kcl-lib 0.2.186

use std::collections::HashMap;
use std::sync::Arc;

use async_recursion::async_recursion;
use ezpz::Constraint;
use ezpz::NonLinearSystemError;
use ezpz::datatypes::inputs::DatumPoint;
use indexmap::IndexMap;
use kcl_api::Group;
use kcl_api::NumericType;
use kcl_api::Operation;
use kcl_api::UnitAngle;

use crate::CompilationIssue;
use crate::NodePath;
use crate::NodePathExt;
use crate::SourceRange;
use crate::errors::KclError;
use crate::errors::KclErrorDetails;
use crate::exec::Sketch;
use crate::execution::AbstractSegment;
use crate::execution::AngleConstraintMode;
use crate::execution::AngleRayDirection;
use crate::execution::AngleSector;
use crate::execution::Artifact;
use crate::execution::ArtifactId;
use crate::execution::BodyType;
use crate::execution::ConstrainableLine2d;
use crate::execution::ConstraintKind;
use crate::execution::EarlyReturn;
use crate::execution::EnvironmentRef;
use crate::execution::ExecState;
use crate::execution::ExecutorContext;
use crate::execution::KclValue;
use crate::execution::KclValueControlFlow;
use crate::execution::KclVersion;
use crate::execution::LegacyAngleRefactorMeta;
use crate::execution::Metadata;
use crate::execution::ModelingCmdMeta;
use crate::execution::ModuleArtifactState;
use crate::execution::PendingLegacyAngleRefactorMeta;
use crate::execution::PreserveMem;
use crate::execution::RefactorMetadata;
use crate::execution::SKETCH_BLOCK_PARAM_ON;
use crate::execution::SKETCH_OBJECT_META;
use crate::execution::SKETCH_OBJECT_META_SKETCH;
use crate::execution::Segment;
use crate::execution::SegmentKind;
use crate::execution::SegmentRepr;
use crate::execution::SketchConstraintKind;
use crate::execution::SketchSurface;
use crate::execution::SolverArc;
use crate::execution::StatementKind;
use crate::execution::TagIdentifier;
use crate::execution::UnsolvedExpr;
use crate::execution::UnsolvedSegment;
use crate::execution::UnsolvedSegmentKind;
use crate::execution::annotations;
use crate::execution::annotations::FnAttrs;
use crate::execution::cad_op::op_from_kcl_value;
use crate::execution::control_continue;
use crate::execution::early_return;
use crate::execution::fn_call::Arg;
use crate::execution::fn_call::Args;
use crate::execution::fn_call::unexpected_kw_arg_message;
use crate::execution::kcl_value::EnumTypeDef;
use crate::execution::kcl_value::EnumTypeId;
use crate::execution::kcl_value::EnumValue;
use crate::execution::kcl_value::FunctionSource;
use crate::execution::kcl_value::KclFunctionSourceParams;
use crate::execution::kcl_value::KclObjectKind;
use crate::execution::kcl_value::TypeDef;
use crate::execution::memory::SKETCH_PREFIX;
use crate::execution::memory::{self};
use crate::execution::sketch_constraint_status_for_sketch;
use crate::execution::sketch_solve::FreedomAnalysis;
use crate::execution::sketch_solve::Solved;
use crate::execution::sketch_solve::UnsatisfiedDirectionalConstraint;
use crate::execution::sketch_solve::create_segment_scene_objects;
use crate::execution::sketch_solve::normalize_to_solver_angle_unit;
use crate::execution::sketch_solve::normalize_to_solver_distance_unit;
use crate::execution::sketch_solve::solver_numeric_type;
use crate::execution::sketch_solve::substitute_sketch_var_in_segment;
use crate::execution::sketch_solve::substitute_sketch_vars;
use crate::execution::state::ModuleState;
use crate::execution::state::SketchBlockState;
use crate::execution::types::CoercionMode;
use crate::execution::types::NumericTypeExt;
use crate::execution::types::PrimitiveType;
use crate::execution::types::RuntimeType;
use crate::execution::types::resolve_named_type_def;
use crate::execution::types::type_value_named_by_segment;
use crate::front::ArcDirection;
use crate::front::LineCtor;
use crate::front::Object;
use crate::front::ObjectId;
use crate::front::ObjectKind;
use crate::front::PointCtor;
use crate::modules::ModuleExecutionOutcome;
use crate::modules::ModuleId;
use crate::modules::ModulePath;
use crate::modules::ModuleRepr;
use crate::parsing::ast::types::ABSOLUTE_PATHS_NOT_SUPPORTED;
use crate::parsing::ast::types::Annotation;
use crate::parsing::ast::types::ArrayExpression;
use crate::parsing::ast::types::ArrayRangeExpression;
use crate::parsing::ast::types::AscribedExpression;
use crate::parsing::ast::types::BinaryExpression;
use crate::parsing::ast::types::BinaryOperator;
use crate::parsing::ast::types::BinaryPart;
use crate::parsing::ast::types::BodyItem;
use crate::parsing::ast::types::CodeBlock;
use crate::parsing::ast::types::Expr;
use crate::parsing::ast::types::FunctionExpression;
use crate::parsing::ast::types::Identifier;
use crate::parsing::ast::types::IfExpression;
use crate::parsing::ast::types::ImportPath;
use crate::parsing::ast::types::ImportSelector;
use crate::parsing::ast::types::ImportStatement;
use crate::parsing::ast::types::ItemVisibility;
use crate::parsing::ast::types::MemberExpression;
use crate::parsing::ast::types::Name;
use crate::parsing::ast::types::Node;
use crate::parsing::ast::types::ObjectExpression;
use crate::parsing::ast::types::PipeExpression;
use crate::parsing::ast::types::Program;
use crate::parsing::ast::types::ReturnStatement;
use crate::parsing::ast::types::SketchBlock;
use crate::parsing::ast::types::SketchVar;
use crate::parsing::ast::types::TagDeclarator;
use crate::parsing::ast::types::Type;
use crate::parsing::ast::types::TypeDeclaration;
use crate::parsing::ast::types::TypeDeclarationDefinition;
use crate::parsing::ast::types::UnaryExpression;
use crate::parsing::ast::types::UnaryOperator;
use crate::parsing::ast::types::VariableDeclaration;
use crate::std::StdFnProps;
use crate::std::args::FromKclValue;
use crate::std::args::TyF64;
use crate::std::shapes::SketchOrSurface;
use crate::std::sketch::ensure_sketch_plane_in_engine;
use crate::std::solver::SOLVER_CONVERGENCE_TOLERANCE;
use crate::std::solver::create_segments_in_engine;
use crate::std::utils::intersect_lines_2d;
use crate::std::utils::normalize_rad;
use crate::std::utils::vec2_dot;
use crate::std::utils::vec2_len;
use crate::std::utils::vec2_sub;
use crate::walk::Visitable;

fn internal_err(message: impl Into<String>, range: impl Into<SourceRange>) -> KclError {
    KclError::new_internal(KclErrorDetails::new(message.into(), vec![range.into()]))
}

fn signed_distance_conflict_hint(solve_outcome: &Solved) -> String {
    let hints = solve_outcome
        .unsatisfied_directional_constraints
        .iter()
        .map(|constraint| match constraint {
            UnsatisfiedDirectionalConstraint::Horizontal(expected) if *expected > 0.0 => {
                "Unsatisfied signed horizontalDistance constraint: a positive right-hand side requires the second point to be right of the first (second.x - first.x > 0)."
            }
            UnsatisfiedDirectionalConstraint::Horizontal(expected) if *expected < 0.0 => {
                "Unsatisfied signed horizontalDistance constraint: a negative right-hand side requires the second point to be left of the first (second.x - first.x < 0)."
            }
            UnsatisfiedDirectionalConstraint::Horizontal(_) => {
                "Unsatisfied signed horizontalDistance constraint: a zero right-hand side requires both points to have the same X coordinate."
            }
            UnsatisfiedDirectionalConstraint::Vertical(expected) if *expected > 0.0 => {
                "Unsatisfied signed verticalDistance constraint: a positive right-hand side requires the second point to be above the first (second.y - first.y > 0)."
            }
            UnsatisfiedDirectionalConstraint::Vertical(expected) if *expected < 0.0 => {
                "Unsatisfied signed verticalDistance constraint: a negative right-hand side requires the second point to be below the first (second.y - first.y < 0)."
            }
            UnsatisfiedDirectionalConstraint::Vertical(_) => {
                "Unsatisfied signed verticalDistance constraint: a zero right-hand side requires both points to have the same Y coordinate."
            }
        })
        .collect::<Vec<_>>();

    if hints.is_empty() {
        String::new()
    } else {
        format!(" {}", hints.join(" "))
    }
}

fn datum_point_from_constrainable(
    point: &crate::execution::ConstrainablePoint2d,
    range: SourceRange,
) -> Result<ezpz::datatypes::inputs::DatumPoint, KclError> {
    Ok(ezpz::datatypes::inputs::DatumPoint::new_xy(
        point.vars.x.to_constraint_id(range)?,
        point.vars.y.to_constraint_id(range)?,
    ))
}

fn push_fixed_origin_point(
    sketch_block_state: &mut SketchBlockState,
    sketch_var_ty: NumericType,
    range: SourceRange,
) -> Result<ezpz::datatypes::inputs::DatumPoint, KclError> {
    let origin_x_id = sketch_block_state.next_sketch_var_id();
    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
        value: Box::new(crate::execution::SketchVar {
            id: origin_x_id,
            initial_value: 0.0,
            ty: sketch_var_ty,
            // Synthesized fixed origin coord; not source-backed.
            node_path: None,
            meta: vec![],
        }),
    });
    let origin_y_id = sketch_block_state.next_sketch_var_id();
    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
        value: Box::new(crate::execution::SketchVar {
            id: origin_y_id,
            initial_value: 0.0,
            ty: sketch_var_ty,
            // Synthesized fixed origin coord; not source-backed.
            node_path: None,
            meta: vec![],
        }),
    });

    sketch_block_state
        .solver_constraints
        .push(Constraint::Fixed(origin_x_id.to_constraint_id(range)?, 0.0));
    sketch_block_state
        .solver_constraints
        .push(Constraint::Fixed(origin_y_id.to_constraint_id(range)?, 0.0));

    Ok(ezpz::datatypes::inputs::DatumPoint::new_xy(
        origin_x_id.to_constraint_id(range)?,
        origin_y_id.to_constraint_id(range)?,
    ))
}

fn datum_point_from_constrainable_or_origin(
    sketch_block_state: &mut SketchBlockState,
    sketch_var_ty: NumericType,
    point: &crate::execution::ConstrainablePoint2dOrOrigin,
    range: SourceRange,
) -> Result<ezpz::datatypes::inputs::DatumPoint, KclError> {
    match point {
        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => datum_point_from_constrainable(point, range),
        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
            push_fixed_origin_point(sketch_block_state, sketch_var_ty, range)
        }
    }
}

fn datum_line_from_constrainable(
    line: &crate::execution::ConstrainableLine2d,
    range: SourceRange,
) -> Result<ezpz::datatypes::inputs::DatumLineSegment, KclError> {
    Ok(ezpz::datatypes::inputs::DatumLineSegment::new(
        ezpz::datatypes::inputs::DatumPoint::new_xy(
            line.vars[0].x.to_constraint_id(range)?,
            line.vars[0].y.to_constraint_id(range)?,
        ),
        ezpz::datatypes::inputs::DatumPoint::new_xy(
            line.vars[1].x.to_constraint_id(range)?,
            line.vars[1].y.to_constraint_id(range)?,
        ),
    ))
}

fn push_hidden_sketch_point(
    sketch_block_state: &mut SketchBlockState,
    sketch_var_ty: NumericType,
    initial: [f64; 2],
    range: SourceRange,
) -> Result<DatumPoint, KclError> {
    let x_id = sketch_block_state.next_sketch_var_id();
    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
        value: Box::new(crate::execution::SketchVar {
            id: x_id,
            initial_value: initial[0],
            ty: sketch_var_ty,
            node_path: None,
            meta: vec![],
        }),
    });
    let y_id = sketch_block_state.next_sketch_var_id();
    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
        value: Box::new(crate::execution::SketchVar {
            id: y_id,
            initial_value: initial[1],
            ty: sketch_var_ty,
            node_path: None,
            meta: vec![],
        }),
    });

    Ok(DatumPoint::new_xy(
        x_id.to_constraint_id(range)?,
        y_id.to_constraint_id(range)?,
    ))
}

fn front_angle_sector(sector: AngleSector) -> u8 {
    match sector {
        AngleSector::One => 1,
        AngleSector::Two => 2,
        AngleSector::Three => 3,
        AngleSector::Four => 4,
    }
}

#[derive(Clone, Copy)]
struct AngleSectorRay {
    line_index: usize,
    direction: AngleRayDirection,
}

fn angle_sector_rays(sector: AngleSector, is_inverse: bool) -> [AngleSectorRay; 2] {
    let rays = match sector {
        AngleSector::One => [
            AngleSectorRay {
                line_index: 0,
                direction: AngleRayDirection::Forward,
            },
            AngleSectorRay {
                line_index: 1,
                direction: AngleRayDirection::Forward,
            },
        ],
        AngleSector::Two => [
            AngleSectorRay {
                line_index: 1,
                direction: AngleRayDirection::Forward,
            },
            AngleSectorRay {
                line_index: 0,
                direction: AngleRayDirection::Reverse,
            },
        ],
        AngleSector::Three => [
            AngleSectorRay {
                line_index: 0,
                direction: AngleRayDirection::Reverse,
            },
            AngleSectorRay {
                line_index: 1,
                direction: AngleRayDirection::Reverse,
            },
        ],
        AngleSector::Four => [
            AngleSectorRay {
                line_index: 1,
                direction: AngleRayDirection::Reverse,
            },
            AngleSectorRay {
                line_index: 0,
                direction: AngleRayDirection::Forward,
            },
        ],
    };
    if is_inverse { [rays[1], rays[0]] } else { rays }
}

fn line_endpoint_datum(
    line: &ConstrainableLine2d,
    endpoint_index: usize,
    range: SourceRange,
) -> Result<DatumPoint, KclError> {
    let Some(endpoint) = line.vars.get(endpoint_index) else {
        return Err(internal_err("Invalid angle line endpoint index", range));
    };

    Ok(DatumPoint::new_xy(
        endpoint.x.to_constraint_id(range)?,
        endpoint.y.to_constraint_id(range)?,
    ))
}

fn representative_angle_endpoint(
    line: &ConstrainableLine2d,
    initial_line: ([f64; 2], [f64; 2]),
    vertex: [f64; 2],
    range: SourceRange,
) -> Result<(DatumPoint, AngleRayDirection), KclError> {
    let start_delta = vec2_sub(initial_line.0, vertex);
    let end_delta = vec2_sub(initial_line.1, vertex);
    let endpoint_index = if vec2_len(end_delta) >= vec2_len(start_delta) {
        1
    } else {
        0
    };
    let endpoint_delta = if endpoint_index == 1 { end_delta } else { start_delta };
    if vec2_len(endpoint_delta) <= 1e-9 {
        return Err(KclError::new_semantic(KclErrorDetails::new(
            "angleDimension(lines = ..., sector = ...) requires each line to have an endpoint away from the intersection"
                .to_owned(),
            vec![range],
        )));
    }

    let line_direction = vec2_sub(initial_line.1, initial_line.0);
    let direction = if vec2_dot(endpoint_delta, line_direction) >= 0.0 {
        AngleRayDirection::Forward
    } else {
        AngleRayDirection::Reverse
    };

    Ok((line_endpoint_datum(line, endpoint_index, range)?, direction))
}

fn remap_angle_for_representative_rays(
    requested_rays: [AngleSectorRay; 2],
    representative_directions: [AngleRayDirection; 2],
    desired_angle: ezpz::datatypes::Angle,
) -> ezpz::datatypes::Angle {
    let mut requested_directions = representative_directions;
    for ray in requested_rays {
        requested_directions[ray.line_index] = ray.direction;
    }

    let sign_offset = if (requested_directions[0] != representative_directions[0])
        ^ (requested_directions[1] != representative_directions[1])
    {
        std::f64::consts::PI
    } else {
        0.0
    };

    let desired = desired_angle.to_radians();
    let representative_angle = if requested_rays[0].line_index == 0 {
        desired - sign_offset
    } else {
        -desired - sign_offset
    };

    ezpz::datatypes::Angle::from_radians(normalize_rad(representative_angle))
}

struct PointsAtAngleLineData {
    initial_vertex: [f64; 2],
    representative_points: [DatumPoint; 2],
    angle_kind: ezpz::datatypes::AngleKind,
}

enum AngleConstraintLowering {
    LinesAtAngle(Box<PendingLegacyAngleRefactorMeta>),
    PointsAtAngle(PointsAtAngleLineData),
}

fn solved_angle_line(line: &ConstrainableLine2d, final_values: &[f64]) -> Option<([f64; 2], [f64; 2])> {
    let point = |index: usize| {
        let point = line.vars.get(index)?;
        Some([*final_values.get(point.x.0)?, *final_values.get(point.y.0)?])
    };
    Some((point(0)?, point(1)?))
}

fn angle_ray_vector(lines: [[f64; 2]; 2], ray: AngleSectorRay) -> [f64; 2] {
    let direction = lines[ray.line_index];
    match ray.direction {
        AngleRayDirection::Forward => direction,
        AngleRayDirection::Reverse => [-direction[0], -direction[1]],
    }
}

fn directed_angle(from: [f64; 2], to: [f64; 2]) -> f64 {
    let cross = from[0] * to[1] - from[1] * to[0];
    libm::atan2(cross, vec2_dot(from, to)).rem_euclid(std::f64::consts::TAU)
}

fn circular_angle_distance(a: f64, b: f64) -> f64 {
    let delta = (a - b).abs().rem_euclid(std::f64::consts::TAU);
    libm::fmin(delta, std::f64::consts::TAU - delta)
}

fn legacy_angle_arc_midpoint_angle(
    lines: [([f64; 2], [f64; 2]); 2],
    directions: [[f64; 2]; 2],
    vertex: [f64; 2],
    desired: f64,
) -> f64 {
    let signed_distances = lines.map(|line| {
        let direction = vec2_sub(line.1, line.0);
        let length = vec2_len(direction);
        [
            vec2_dot(vec2_sub(line.0, vertex), direction) / length,
            vec2_dot(vec2_sub(line.1, vertex), direction) / length,
        ]
    });
    let overlap = [
        libm::fmax(signed_distances[0][0], signed_distances[1][0]),
        libm::fmin(signed_distances[0][1], signed_distances[1][1]),
    ];
    // Match calculateArcRenderInput in src/machines/sketchSolve/constraints/AngleConstraintBuilder.ts;
    // the radius sign chooses the line 0 ray on which the legacy arc starts.
    let radius = if overlap[1] >= overlap[0] {
        let near_start = overlap[0] + (overlap[1] - overlap[0]) * 0.15;
        let near_end = overlap[0] + (overlap[1] - overlap[0]) * 0.85;
        if near_start.abs() < near_end.abs() {
            near_start
        } else {
            near_end
        }
    } else {
        let mut distances = signed_distances.into_iter().flatten().collect::<Vec<_>>();
        distances.sort_by(f64::total_cmp);
        distances[1]
    };
    let start = if radius < 0.0 {
        [-directions[0][0], -directions[0][1]]
    } else {
        directions[0]
    };

    (libm::atan2(start[1], start[0]) + desired * 0.5).rem_euclid(std::f64::consts::TAU)
}

fn finalize_legacy_angle_refactor_meta(
    pending: &PendingLegacyAngleRefactorMeta,
    final_values: &[f64],
) -> Option<LegacyAngleRefactorMeta> {
    let line0 = solved_angle_line(&pending.lines[0], final_values)?;
    let line1 = solved_angle_line(&pending.lines[1], final_values)?;
    let vertex = intersect_lines_2d(line0, line1)?;
    let directions = [vec2_sub(line0.1, line0.0), vec2_sub(line1.1, line1.0)];
    if directions.iter().any(|direction| vec2_len(*direction) <= 1e-9) {
        return None;
    }

    let desired = pending.desired_angle_radians.rem_euclid(std::f64::consts::TAU);
    let sectors = [
        AngleSector::One,
        AngleSector::Two,
        AngleSector::Three,
        AngleSector::Four,
    ];
    let mut candidates = Vec::new();
    for sector in sectors {
        for inverse in [false, true] {
            let rays = angle_sector_rays(sector, inverse);
            let from = angle_ray_vector(directions, rays[0]);
            let to = angle_ray_vector(directions, rays[1]);
            if circular_angle_distance(directed_angle(from, to), desired) <= 1e-5 {
                let midpoint = libm::atan2(from[1], from[0]) + desired * 0.5;
                candidates.push((sector, inverse, midpoint.rem_euclid(std::f64::consts::TAU)));
            }
        }
    }

    let arc_midpoint_angle = legacy_angle_arc_midpoint_angle([line0, line1], directions, vertex, desired);
    let selected = candidates.into_iter().min_by(|a, b| {
        circular_angle_distance(a.2, arc_midpoint_angle).total_cmp(&circular_angle_distance(b.2, arc_midpoint_angle))
    })?;

    Some(LegacyAngleRefactorMeta {
        source_range: pending.source_range,
        sector: front_angle_sector(selected.0),
        inverse: selected.1,
    })
}

fn push_points_at_angle_for_lines(
    sketch_block_state: &mut SketchBlockState,
    sketch_var_ty: NumericType,
    lines: [&ConstrainableLine2d; 2],
    data: PointsAtAngleLineData,
    range: SourceRange,
) -> Result<(), KclError> {
    let solver_line0 = datum_line_from_constrainable(lines[0], range)?;
    let solver_line1 = datum_line_from_constrainable(lines[1], range)?;
    let vertex = push_hidden_sketch_point(sketch_block_state, sketch_var_ty, data.initial_vertex, range)?;

    sketch_block_state
        .solver_constraints
        .push(Constraint::PointLineDistance(vertex, solver_line0, 0.0));
    sketch_block_state
        .solver_constraints
        .push(Constraint::PointLineDistance(vertex, solver_line1, 0.0));
    sketch_block_state.solver_constraints.push(Constraint::PointsAtAngle(
        vertex,
        data.representative_points[0],
        data.representative_points[1],
        data.angle_kind,
    ));

    Ok(())
}

fn sketch_var_initial_value(
    sketch_vars: &[KclValue],
    id: crate::execution::SketchVarId,
    exec_state: &mut ExecState,
    range: SourceRange,
    description: &str,
) -> Result<f64, KclError> {
    sketch_vars
        .get(id.0)
        .and_then(KclValue::as_sketch_var)
        .map(|sketch_var| {
            sketch_var
                .initial_value_to_solver_units(exec_state, range, description)
                .map(|value| value.n)
        })
        .transpose()?
        .ok_or_else(|| internal_err(format!("Missing sketch variable initial value for id {}", id.0), range))
}

fn constrainable_point_initial_position(
    sketch_vars: &[KclValue],
    point: &crate::execution::ConstrainablePoint2d,
    exec_state: &mut ExecState,
    range: SourceRange,
    description: &str,
) -> Result<[f64; 2], KclError> {
    Ok([
        sketch_var_initial_value(sketch_vars, point.vars.x, exec_state, range, description)?,
        sketch_var_initial_value(sketch_vars, point.vars.y, exec_state, range, description)?,
    ])
}

fn constrainable_point_or_origin_initial_position(
    sketch_vars: &[KclValue],
    point: &crate::execution::ConstrainablePoint2dOrOrigin,
    exec_state: &mut ExecState,
    range: SourceRange,
    description: &str,
) -> Result<[f64; 2], KclError> {
    match point {
        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
            constrainable_point_initial_position(sketch_vars, point, exec_state, range, description)
        }
        crate::execution::ConstrainablePoint2dOrOrigin::Origin => Ok([0.0, 0.0]),
    }
}

// These helpers read the current sketch variable guesses so hidden support
// geometry starts near the geometry the user selected. The visible constraint
// value still comes from the KCL RHS. These initial values are only solver
// seeds for new hidden points/radii, which helps ezpz converge to the intended
// geometric branch instead of an equivalent but visually surprising one.
fn constrainable_line_initial_positions(
    sketch_vars: &[KclValue],
    line: &crate::execution::ConstrainableLine2d,
    exec_state: &mut ExecState,
    range: SourceRange,
    description: &str,
) -> Result<([f64; 2], [f64; 2]), KclError> {
    let start = crate::execution::ConstrainablePoint2d {
        vars: line.vars[0].clone(),
        object_id: line.object_id,
    };
    let end = crate::execution::ConstrainablePoint2d {
        vars: line.vars[1].clone(),
        object_id: line.object_id,
    };
    Ok((
        constrainable_point_initial_position(sketch_vars, &start, exec_state, range, description)?,
        constrainable_point_initial_position(sketch_vars, &end, exec_state, range, description)?,
    ))
}

fn projected_point_on_line_initial_position(
    sketch_vars: &[KclValue],
    point: &crate::execution::ConstrainablePoint2dOrOrigin,
    line: &crate::execution::ConstrainableLine2d,
    exec_state: &mut ExecState,
    range: SourceRange,
) -> Result<[f64; 2], KclError> {
    let point = constrainable_point_or_origin_initial_position(
        sketch_vars,
        point,
        exec_state,
        range,
        "point-line distance initial point",
    )?;
    let (line_start, line_end) =
        constrainable_line_initial_positions(sketch_vars, line, exec_state, range, "point-line distance initial line")?;
    let dx = line_end[0] - line_start[0];
    let dy = line_end[1] - line_start[1];
    let len_sq = dx * dx + dy * dy;
    if len_sq == 0.0 {
        return Err(KclError::new_semantic(KclErrorDetails::new(
            "distance() line input must have non-zero length".to_owned(),
            vec![range],
        )));
    }

    // Project the point onto the infinite target line. `t` is the scalar
    // projection of the point-start vector onto the line direction.
    let t = ((point[0] - line_start[0]) * dx + (point[1] - line_start[1]) * dy) / len_sq;
    Ok([line_start[0] + t * dx, line_start[1] + t * dy])
}

fn constrainable_points_initial_distance(
    sketch_vars: &[KclValue],
    point0: &crate::execution::ConstrainablePoint2d,
    point1: &crate::execution::ConstrainablePoint2d,
    exec_state: &mut ExecState,
    range: SourceRange,
    description: &str,
) -> Result<f64, KclError> {
    let p0 = constrainable_point_initial_position(sketch_vars, point0, exec_state, range, description)?;
    let p1 = constrainable_point_initial_position(sketch_vars, point1, exec_state, range, description)?;
    Ok(libm::hypot(p0[0] - p1[0], p0[1] - p1[1]))
}

// Circular distance lowering needs an ezpz DatumCircle, but arcs/circles in
// KCL are represented by points. This bundles the center/start/end datums and
// seeds a hidden radius variable from the current center-start distance.
#[derive(Clone, Copy)]
struct CircularDistanceDatums {
    center: ezpz::datatypes::inputs::DatumPoint,
    start: ezpz::datatypes::inputs::DatumPoint,
    end: Option<ezpz::datatypes::inputs::DatumPoint>,
    radius_initial_value: f64,
}

fn circular_distance_datums(
    sketch_vars: &[KclValue],
    center: &crate::execution::ConstrainablePoint2d,
    start: &crate::execution::ConstrainablePoint2d,
    end: Option<&crate::execution::ConstrainablePoint2d>,
    exec_state: &mut ExecState,
    range: SourceRange,
) -> Result<CircularDistanceDatums, KclError> {
    Ok(CircularDistanceDatums {
        center: datum_point_from_constrainable(center, range)?,
        start: datum_point_from_constrainable(start, range)?,
        end: end.map(|end| datum_point_from_constrainable(end, range)).transpose()?,
        radius_initial_value: constrainable_points_initial_distance(
            sketch_vars,
            center,
            start,
            exec_state,
            range,
            "circular distance radius initial value",
        )?,
    })
}

fn circular_circular_support_initial_position(
    sketch_vars: &[KclValue],
    center0: &crate::execution::ConstrainablePoint2d,
    center1: &crate::execution::ConstrainablePoint2d,
    radius0: f64,
    distance_value: f64,
    exec_state: &mut ExecState,
    range: SourceRange,
) -> Result<[f64; 2], KclError> {
    let center0_initial =
        constrainable_point_initial_position(sketch_vars, center0, exec_state, range, "circular distance center")?;
    let center1_initial =
        constrainable_point_initial_position(sketch_vars, center1, exec_state, range, "circular distance center")?;
    let dx = center1_initial[0] - center0_initial[0];
    let dy = center1_initial[1] - center0_initial[1];
    let center_distance = libm::hypot(dx, dy);
    // The circular-circular distance lowering uses a hidden spacer circle
    // with radius d/2 tangent to both targets. Seed its center on the
    // center-to-center ray at r0 + d/2 so the nonlinear solver starts on the
    // intended between-centers tangency branch.
    let support_distance = radius0 + distance_value / 2.0;

    if center_distance <= f64::EPSILON {
        // Concentric initial guesses have no center-to-center direction, so
        // pick a deterministic horizontal ray for the hidden spacer point.
        return Ok([center0_initial[0] + support_distance, center0_initial[1]]);
    }

    Ok([
        center0_initial[0] + dx / center_distance * support_distance,
        center0_initial[1] + dy / center_distance * support_distance,
    ])
}

fn push_circular_radius_constraints(
    sketch_block_state: &mut SketchBlockState,
    sketch_var_ty: NumericType,
    circular: CircularDistanceDatums,
    range: SourceRange,
) -> Result<ezpz::datatypes::inputs::DatumCircle, KclError> {
    // Create a hidden radius variable and constrain the circular segment's
    // defining points to it. For arcs, both start and end stay on the same
    // radius; for circles, the start point alone defines the radius.
    let circular_radius_id = sketch_block_state.next_sketch_var_id();
    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
        value: Box::new(crate::execution::SketchVar {
            id: circular_radius_id,
            initial_value: circular.radius_initial_value,
            ty: sketch_var_ty,
            // Synthesized hidden radius for circular distance; not source-backed.
            node_path: None,
            meta: vec![],
        }),
    });
    let circular_radius = ezpz::datatypes::inputs::DatumDistance::new(circular_radius_id.to_constraint_id(range)?);

    sketch_block_state.solver_constraints.push(Constraint::DistanceVar(
        circular.start,
        circular.center,
        circular_radius,
    ));
    if let Some(end) = circular.end {
        sketch_block_state
            .solver_constraints
            .push(Constraint::DistanceVar(end, circular.center, circular_radius));
    }

    Ok(ezpz::datatypes::inputs::DatumCircle {
        center: circular.center,
        radius: circular_radius,
    })
}

fn push_circular_distance_constraints(
    sketch_block_state: &mut SketchBlockState,
    sketch_var_ty: NumericType,
    target_point: ezpz::datatypes::inputs::DatumPoint,
    circular: CircularDistanceDatums,
    distance_value: f64,
    range: SourceRange,
) -> Result<(), KclError> {
    let circular_target = push_circular_radius_constraints(sketch_block_state, sketch_var_ty, circular, range)?;

    // Point-circular distance becomes tangency between the target circle and
    // a hidden circle centered on the point with radius equal to the distance.
    let target_distance_id = sketch_block_state.next_sketch_var_id();
    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
        value: Box::new(crate::execution::SketchVar {
            id: target_distance_id,
            initial_value: distance_value,
            ty: sketch_var_ty,
            // Synthesized hidden distance for point-circular tangency; not source-backed.
            node_path: None,
            meta: vec![],
        }),
    });
    let target_distance = ezpz::datatypes::inputs::DatumDistance::new(target_distance_id.to_constraint_id(range)?);

    sketch_block_state
        .solver_constraints
        .push(Constraint::Fixed(target_distance.id, distance_value));

    let target_circle = ezpz::datatypes::inputs::DatumCircle {
        center: target_point,
        radius: target_distance,
    };
    sketch_block_state
        .solver_constraints
        .push(Constraint::CircleTangentToCircle(
            target_circle,
            circular_target,
            ezpz::CircleSide::Exterior,
        ));

    Ok(())
}

fn sketch_on_cache_name(sketch_id: ObjectId) -> String {
    format!("{SKETCH_PREFIX}{}_on", sketch_id.0)
}

fn default_plane_name_from_expr(expr: &Expr) -> Option<crate::engine::PlaneName> {
    fn parse_name(name: &str, negative: bool) -> Option<crate::engine::PlaneName> {
        use crate::engine::PlaneName;

        match (name, negative) {
            ("XY", false) => Some(PlaneName::Xy),
            ("XY", true) => Some(PlaneName::NegXy),
            ("XZ", false) => Some(PlaneName::Xz),
            ("XZ", true) => Some(PlaneName::NegXz),
            ("YZ", false) => Some(PlaneName::Yz),
            ("YZ", true) => Some(PlaneName::NegYz),
            _ => None,
        }
    }

    match expr {
        Expr::Name(name) => {
            if !name.path.is_empty() {
                return None;
            }
            parse_name(&name.name.name, false)
        }
        Expr::UnaryExpression(unary) => {
            if unary.operator != UnaryOperator::Neg {
                return None;
            }
            let crate::parsing::ast::types::BinaryPart::Name(name) = &unary.argument else {
                return None;
            };
            if !name.path.is_empty() {
                return None;
            }
            parse_name(&name.name.name, true)
        }
        _ => None,
    }
}

fn sketch_on_frontend_plane(
    arguments: &[crate::parsing::ast::types::LabeledArg],
    on_object_id: crate::front::ObjectId,
) -> crate::front::Plane {
    for arg in arguments {
        let Some(label) = &arg.label else {
            continue;
        };
        if label.name != SKETCH_BLOCK_PARAM_ON {
            continue;
        }
        if let Some(name) = default_plane_name_from_expr(&arg.arg) {
            return crate::front::Plane::Default(name);
        }
        break;
    }

    crate::front::Plane::Object(on_object_id)
}

impl<'a> StatementKind<'a> {
    fn expect_name(&self) -> &'a str {
        match self {
            StatementKind::Declaration { name } => name,
            StatementKind::Expression => unreachable!(),
        }
    }
}

impl ExecutorContext {
    /// Returns true if importing the prelude should be skipped.
    pub(super) async fn handle_annotations(
        &self,
        annotations: impl Iterator<Item = &Node<Annotation>>,
        body_type: BodyType,
        exec_state: &mut ExecState,
    ) -> Result<bool, KclError> {
        let mut no_prelude = false;
        for annotation in annotations {
            // The attribute that customizes diagnostics is `@warnings` before
            // KCL 3.0 and `@diagnostics` in KCL 3.0 and later. Look it up per
            // annotation since a preceding `@settings` may have changed the
            // version.
            let diagnostics_attr = annotations::diagnostics_attr_name(exec_state.kcl_version());
            if annotation.name() == Some(annotations::SETTINGS) {
                if matches!(body_type, BodyType::Root) {
                    let (updated_len, updated_angle) =
                        exec_state.mod_local.settings.update_from_annotation(annotation)?;
                    if updated_len {
                        exec_state.mod_local.explicit_length_units = true;
                    }
                    if updated_angle {
                        if exec_state.kcl_version() >= KclVersion::V3Preview {
                            return Err(KclError::new_semantic(KclErrorDetails::new(
                                "The `defaultAngleUnit` setting was removed in KCL 3.0; use explicit units for angles"
                                    .to_owned(),
                                annotation.as_source_ranges(),
                            )));
                        }
                        exec_state.warn(
                            CompilationIssue::err(
                                annotation.as_source_range(),
                                "The `defaultAngleUnit` setting is deprecated; use explicit units for angles",
                            ),
                            annotations::WARN_ANGLE_UNITS,
                        );
                    }
                } else {
                    exec_state.err(CompilationIssue::err(
                        annotation.as_source_range(),
                        "Settings can only be modified at the top level scope of a file",
                    ));
                }
            } else if annotation.name() == Some(annotations::NO_PRELUDE) {
                if matches!(body_type, BodyType::Root) {
                    no_prelude = true;
                } else {
                    exec_state.err(CompilationIssue::err(
                        annotation.as_source_range(),
                        "The standard library can only be skipped at the top level scope of a file",
                    ));
                }
            } else if annotation.name() == Some(diagnostics_attr) {
                // TODO we should support setting warnings for the whole project, not just one file
                if matches!(body_type, BodyType::Root) {
                    let props = annotations::expect_properties(diagnostics_attr, annotation)?;
                    for p in props {
                        match &*p.inner.key.name {
                            annotations::WARN_ALLOW => {
                                let allowed = annotations::many_of(
                                    &p.inner.value,
                                    &annotations::WARN_VALUES,
                                    diagnostics_attr,
                                    annotation.as_source_range(),
                                )?;
                                exec_state.mod_local.allowed_warnings = allowed;
                            }
                            annotations::WARN_DENY => {
                                let denied = annotations::many_of(
                                    &p.inner.value,
                                    &annotations::WARN_VALUES,
                                    diagnostics_attr,
                                    annotation.as_source_range(),
                                )?;
                                exec_state.mod_local.denied_warnings = denied;
                            }
                            name => {
                                return Err(KclError::new_semantic(KclErrorDetails::new(
                                    format!(
                                        "Unexpected {diagnostics_attr} key: `{name}`; expected one of `{}`, `{}`",
                                        annotations::WARN_ALLOW,
                                        annotations::WARN_DENY,
                                    ),
                                    vec![annotation.as_source_range()],
                                )));
                            }
                        }
                    }
                } else {
                    let message = match diagnostics_attr {
                        annotations::WARNINGS => "Warnings can only be customized at the top level scope of a file",
                        _ => "Diagnostics can only be customized at the top level scope of a file",
                    };
                    exec_state.err(CompilationIssue::err(annotation.as_source_range(), message));
                }
            } else if annotation.name() == Some(annotations::WARNINGS) {
                // KCL 3.0 renamed `@warnings` to `@diagnostics`. This is only
                // reached in KCL 3.0-preview or later, since before that the
                // attribute is handled above. Report a non-fatal error with
                // the fix, and ignore the attribute.
                let mut issue = CompilationIssue::err(
                    annotation.as_source_range(),
                    format!(
                        "The `@{old}` attribute was renamed to `@{new}` in KCL 3.0, so this attribute is ignored. Replace `@{old}` with `@{new}`; its `{allow}` and `{deny}` properties are unchanged.",
                        old = annotations::WARNINGS,
                        new = annotations::DIAGNOSTICS,
                        allow = annotations::WARN_ALLOW,
                        deny = annotations::WARN_DENY,
                    ),
                );
                if let Some(name) = &annotation.name {
                    issue = issue.with_suggestion(
                        format!("Rename to `@{}`", annotations::DIAGNOSTICS),
                        annotations::DIAGNOSTICS,
                        Some(name.as_source_range()),
                        crate::errors::Tag::None,
                    );
                }
                exec_state.err(issue);
            } else {
                exec_state.warn(
                    CompilationIssue::err(annotation.as_source_range(), "Unknown annotation"),
                    annotations::WARN_UNKNOWN_ATTR,
                );
            }
        }
        Ok(no_prelude)
    }

    pub(super) async fn exec_module_body(
        &self,
        program: &Node<Program>,
        exec_state: &mut ExecState,
        preserve_mem: PreserveMem,
        module_id: ModuleId,
        path: &ModulePath,
    ) -> Result<ModuleExecutionOutcome, (KclError, Option<EnvironmentRef>, Option<ModuleArtifactState>)> {
        crate::log::log(format!("enter module {path} {}", exec_state.stack()));

        // KCL 3.0: reject an imported file whose declared kclVersion is not
        // allowed with the entry point's before any of it executes.
        exec_state
            .check_imported_module_kcl_version(path, program, None)
            .map_err(|err| (err, None, None))?;

        // When executing only the new statements in incremental execution or
        // mock executing for sketch mode, we need the scene objects that were
        // created during the last execution, which are in the execution cache.
        // The cache is read to create the initial module state. Depending on
        // whether it's mock execution or engine execution, it's rehydrated
        // differently, so we need to clone them from a different place. Then
        // make sure the object ID generator matches the number of existing
        // scene objects.
        let mut local_state = ModuleState::new(
            path.clone(),
            exec_state.stack().memory.clone(),
            Some(module_id),
            exec_state.mod_local.sketch_mode,
            exec_state.mod_local.freedom_analysis,
        );
        match preserve_mem {
            PreserveMem::Always => {
                exec_state
                    .mod_local
                    .artifacts
                    .restore_scene_objects(&exec_state.global.root_module_artifacts.scene_objects);
            }
            PreserveMem::Normal => {
                local_state
                    .artifacts
                    .restore_scene_objects(&exec_state.mod_local.artifacts.scene_objects);
                std::mem::swap(&mut exec_state.mod_local, &mut local_state);
            }
        }

        let no_prelude = self
            .handle_annotations(program.inner_attrs.iter(), crate::execution::BodyType::Root, exec_state)
            .await
            .map_err(|err| (err, None, None))?;

        if preserve_mem.normal() {
            exec_state
                .mut_stack()
                .push_new_root_env(!no_prelude)
                .map_err(|err| (err, None, None))?;
        }

        let result = self
            .exec_block(program, exec_state, crate::execution::BodyType::Root)
            .await;

        let env_ref = match preserve_mem {
            PreserveMem::Always => exec_state.mut_stack().pop_and_preserve_env(),
            PreserveMem::Normal => exec_state.mut_stack().pop_env(),
        }
        .map_err(|err| (err, None, None))?;
        let module_artifacts = match preserve_mem {
            PreserveMem::Always => std::mem::take(&mut exec_state.mod_local.artifacts),
            PreserveMem::Normal => {
                std::mem::swap(&mut exec_state.mod_local, &mut local_state);
                local_state.artifacts
            }
        };

        crate::log::log(format!("leave {path}"));

        result
            .map_err(|err| (err, Some(env_ref), Some(module_artifacts.clone())))
            .map(|last_expr| ModuleExecutionOutcome {
                last_expr: last_expr.map(|value_cf| value_cf.into_value()),
                environment: env_ref,
                exports: local_state.module_exports,
                artifacts: module_artifacts,
            })
    }

    /// Execute an AST's program.
    #[async_recursion]
    pub(super) async fn exec_block<'a, B>(
        &'a self,
        block: &'a B,
        exec_state: &mut ExecState,
        body_type: BodyType,
    ) -> Result<Option<KclValueControlFlow>, KclError>
    where
        B: CodeBlock + crate::execution::machine::ToMachineBlock + Sync,
    {
        if self.is_machine_executor() {
            return crate::execution::machine::run_block(self, block.to_machine_block(), exec_state, body_type).await;
        }

        let mut last_expr = None;
        // Iterate over the body of the program.
        for statement in block.body() {
            match statement {
                BodyItem::ImportStatement(import_stmt) => {
                    if exec_state.sketch_mode() {
                        continue;
                    }
                    self.exec_import_statement(import_stmt, body_type, exec_state).await?;
                    last_expr = None;
                }
                BodyItem::ExpressionStatement(expression_statement) => {
                    if exec_state.sketch_mode() && sketch_mode_should_skip(&expression_statement.expression) {
                        continue;
                    }

                    let metadata = Metadata::from(expression_statement);
                    let value = self
                        .execute_expr(
                            &expression_statement.expression,
                            exec_state,
                            &metadata,
                            &[],
                            StatementKind::Expression,
                        )
                        .await?;

                    let is_return = value.is_some_return();
                    last_expr = Some(value);

                    if is_return {
                        break;
                    }
                }
                BodyItem::VariableDeclaration(variable_declaration) => {
                    if exec_state.sketch_mode() && sketch_mode_should_skip(&variable_declaration.declaration.init) {
                        continue;
                    }

                    let var_name = variable_declaration.declaration.id.name.to_string();
                    let source_range = SourceRange::from(&variable_declaration.declaration.init);
                    let metadata = Metadata { source_range };

                    let annotations = &variable_declaration.outer_attrs;

                    // During the evaluation of the variable's RHS, set context that this is all happening inside a variable
                    // declaration, for the given name. This helps improve user-facing error messages.
                    let lhs = variable_declaration.inner.name().to_owned();
                    let prev_being_declared = exec_state.mod_local.being_declared.take();
                    exec_state.mod_local.being_declared = Some(lhs);
                    let rhs_result = self
                        .execute_expr(
                            &variable_declaration.declaration.init,
                            exec_state,
                            &metadata,
                            annotations,
                            StatementKind::Declaration { name: &var_name },
                        )
                        .await;
                    // Declaration over, so unset this context.
                    exec_state.mod_local.being_declared = prev_being_declared;
                    let rhs = rhs_result?;

                    if rhs.is_some_return() {
                        last_expr = Some(rhs);
                        break;
                    }
                    let rhs =
                        self.bind_variable_declaration(variable_declaration, rhs.into_value(), body_type, exec_state)?;
                    // Variable declaration can be the return value of a module.
                    last_expr = matches!(body_type, BodyType::Root).then_some(rhs.continue_());
                }
                BodyItem::TypeDeclaration(ty) => {
                    if exec_state.sketch_mode() {
                        continue;
                    }
                    self.exec_type_declaration(ty, body_type, exec_state).await?;
                    last_expr = None;
                }
                BodyItem::ReturnStatement(return_statement) => {
                    if exec_state.sketch_mode() && sketch_mode_should_skip(&return_statement.argument) {
                        continue;
                    }

                    let metadata = Metadata::from(return_statement);

                    if matches!(body_type, BodyType::Root) {
                        return Err(KclError::new_semantic(KclErrorDetails::new(
                            "Cannot return from outside a function.".to_owned(),
                            vec![metadata.source_range],
                        )));
                    }

                    let value_cf = self
                        .execute_expr(
                            &return_statement.argument,
                            exec_state,
                            &metadata,
                            &[],
                            StatementKind::Expression,
                        )
                        .await?;
                    if value_cf.is_some_return() {
                        last_expr = Some(value_cf);
                        break;
                    }
                    let value = value_cf.into_value();
                    if exec_state.entry_point_version_is_v3_or_higher() {
                        // KCL 3.0: early return. The value unwinds as control
                        // flow to the nearest function-call boundary, which
                        // absorbs it; see call_finish.
                        last_expr = Some(value.return_());
                        break;
                    }
                    Self::bind_return_value(return_statement, value, exec_state)?;
                    last_expr = None;
                }
            }
        }

        // A Return can reach a root block only by escaping an expression
        // evaluated at the top level (e.g. an if-arm); a `return` statement
        // here is rejected above before it evaluates.
        if matches!(body_type, BodyType::Root)
            && let Some(cf) = &last_expr
            && cf.is_return()
        {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                "Cannot return from outside a function.".to_owned(),
                cf.source_ranges(),
            )));
        }

        if matches!(body_type, BodyType::Root) {
            // Flush the batch queue.
            exec_state
                .flush_batch(
                    ModelingCmdMeta::new(exec_state, self, block.to_source_range()),
                    // True here tells the engine to flush all the end commands as well like fillets
                    // and chamfers where the engine would otherwise eat the ID of the segments.
                    true,
                )
                .await?;
        }

        Ok(last_expr)
    }

    /// Execute an import statement. Flat: this does not evaluate KCL
    /// sub-expressions (module execution happens in its own fresh root), so
    /// both executors share it.
    pub(super) async fn exec_import_statement(
        &self,
        import_stmt: &Node<ImportStatement>,
        body_type: BodyType,
        exec_state: &mut ExecState,
    ) -> Result<(), KclError> {
        if !matches!(body_type, BodyType::Root) {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                "Imports are only supported at the top-level of a file.".to_owned(),
                vec![import_stmt.into()],
            )));
        }

        let source_range = SourceRange::from(import_stmt);
        let attrs = &import_stmt.outer_attrs;
        let module_path = ModulePath::from_import_path(
            &import_stmt.path,
            &self.settings.project_directory,
            &exec_state.mod_local.path,
        )?;
        let module_id = self
            .open_module(&import_stmt.path, attrs, &module_path, exec_state, source_range)
            .await?;

        // KCL 3.0: check the imported file's declared kclVersion at the import
        // site as well. Mock execution runs a whole-module import's body only
        // when the module is referenced, so for an unreferenced one this is
        // the only place the check can run. In engine execution, every
        // imported module's body (and so this check) ran before the root body
        // got here.
        if let ImportPath::Kcl { .. } = &import_stmt.path
            && let Some(ModuleRepr::Kcl(program, _)) =
                exec_state.global.module_infos.get(&module_id).map(|info| &info.repr)
        {
            exec_state.check_imported_module_kcl_version(&module_path, program, Some(source_range))?;
        }

        if let ModulePath::Local { value, .. } = &module_path {
            let name = import_stmt
                .module_name()
                .unwrap_or_else(|| value.file_name().unwrap_or_default());
            exec_state.push_op(Operation::ModuleInstance {
                name,
                module_id,
                glob: matches!(import_stmt.selector, ImportSelector::Glob(_)),
                node_path: NodePath::placeholder(),
                source_range,
            });
        }

        match &import_stmt.selector {
            ImportSelector::List { items } => {
                let (env_ref, module_exports) = self.exec_module_for_items(module_id, exec_state, source_range).await?;
                for import_item in items {
                    // Extract the item from the module.
                    let mem = &exec_state.stack().memory;
                    let mut value = mem.get_from_owned(&import_item.name.name, env_ref, import_item.into(), 0);
                    let ty_name = format!("{}{}", memory::TYPE_PREFIX, import_item.name.name);
                    let mut ty = mem.get_from_owned(&ty_name, env_ref, import_item.into(), 0);
                    let mod_name = format!("{}{}", memory::MODULE_PREFIX, import_item.name.name);
                    let mut mod_value = mem.get_from_owned(&mod_name, env_ref, import_item.into(), 0);

                    if value.is_err() && ty.is_err() && mod_value.is_err() {
                        return Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("{} is not defined in module", import_item.name.name),
                                vec![SourceRange::from(&import_item.name)],
                            ),
                            None,
                        ));
                    }

                    // Check that the item is allowed to be imported (in at least one namespace).
                    if value.is_ok() && !module_exports.contains(&import_item.name.name) {
                        value = Err(KclError::new_semantic(KclErrorDetails::new(
                            format!(
                                "Cannot import \"{}\" from module because it is not exported. Add \"export\" before the definition to export it.",
                                import_item.name.name
                            ),
                            vec![SourceRange::from(&import_item.name)],
                        )));
                    }

                    if ty.is_ok() && !module_exports.contains(&ty_name) {
                        ty = Err(KclError::new_semantic(KclErrorDetails::new(
                            format!(
                                "Cannot import \"{}\" from module because it is not exported. Add \"export\" before the definition to export it.",
                                import_item.name.name
                            ),
                            vec![SourceRange::from(&import_item.name)],
                        )));
                    }

                    if mod_value.is_ok() && !module_exports.contains(&mod_name) {
                        mod_value = Err(KclError::new_semantic(KclErrorDetails::new(
                            format!(
                                "Cannot import \"{}\" from module because it is not exported. Add \"export\" before the definition to export it.",
                                import_item.name.name
                            ),
                            vec![SourceRange::from(&import_item.name)],
                        )));
                    }

                    if value.is_err() && ty.is_err() && mod_value.is_err() {
                        return value.map(|_| ());
                    }

                    // Add the item to the current module.
                    if let Ok(value) = value {
                        exec_state.mut_stack().add(
                            import_item.identifier().to_owned(),
                            value,
                            SourceRange::from(&import_item.name),
                        )?;

                        if let ItemVisibility::Export = import_stmt.visibility {
                            exec_state
                                .mod_local
                                .module_exports
                                .push(import_item.identifier().to_owned());
                        }
                    }

                    if let Ok(ty) = ty {
                        let ty_name = format!("{}{}", memory::TYPE_PREFIX, import_item.identifier());
                        if matches!(
                            &ty,
                            KclValue::Type {
                                value: TypeDef::Enum(_),
                                ..
                            }
                        ) {
                            reject_enum_clashing_with_module(
                                exec_state,
                                import_item.identifier(),
                                SourceRange::from(&import_item.name),
                            )?;
                        }
                        exec_state
                            .mut_stack()
                            .add(ty_name.clone(), ty, SourceRange::from(&import_item.name))?;

                        if let ItemVisibility::Export = import_stmt.visibility {
                            exec_state.mod_local.module_exports.push(ty_name);
                        }
                    }

                    if let Ok(mod_value) = mod_value {
                        let mod_name = format!("{}{}", memory::MODULE_PREFIX, import_item.identifier());
                        reject_module_clashing_with_enum(
                            exec_state,
                            import_item.identifier(),
                            SourceRange::from(&import_item.name),
                        )?;
                        exec_state.mut_stack().add(
                            mod_name.clone(),
                            mod_value,
                            SourceRange::from(&import_item.name),
                        )?;

                        if let ItemVisibility::Export = import_stmt.visibility {
                            exec_state.mod_local.module_exports.push(mod_name);
                        }
                    }
                }
            }
            ImportSelector::Glob(_) => {
                let (env_ref, module_exports) = self.exec_module_for_items(module_id, exec_state, source_range).await?;
                for name in module_exports.iter() {
                    let item = exec_state
                        .stack()
                        .memory
                        .get_from_owned(name, env_ref, source_range, 0)
                        .map_err(|_err| {
                            internal_err(
                                format!("{name} is not defined in module (but was exported?)"),
                                source_range,
                            )
                        })?;
                    reject_glob_import_clash(exec_state, name, &item, source_range)?;
                    exec_state.mut_stack().add(name.to_owned(), item, source_range)?;

                    if let ItemVisibility::Export = import_stmt.visibility {
                        exec_state.mod_local.module_exports.push(name.clone());
                    }
                }
            }
            ImportSelector::None { .. } => {
                let name = import_stmt.module_name().unwrap();
                reject_module_clashing_with_enum(exec_state, &name, source_range)?;
                let item = KclValue::Module {
                    value: module_id,
                    meta: vec![source_range.into()],
                };
                exec_state
                    .mut_stack()
                    .add(format!("{}{}", memory::MODULE_PREFIX, name), item, source_range)?;
            }
        }

        Ok(())
    }

    /// Execute a type declaration. Flat; shared by both executors.
    pub(super) async fn exec_type_declaration(
        &self,
        ty: &Node<TypeDeclaration>,
        body_type: BodyType,
        exec_state: &mut ExecState,
    ) -> Result<(), KclError> {
        let metadata = Metadata::from(ty);
        let attrs = annotations::get_fn_attrs(&ty.outer_attrs, metadata.source_range)?.unwrap_or_default();
        match attrs.impl_ {
            annotations::Impl::Rust | annotations::Impl::RustConstrainable | annotations::Impl::RustConstraint => {
                let std_path = match &exec_state.mod_local.path {
                    ModulePath::Std { value } => value,
                    ModulePath::Local { .. } | ModulePath::Main => {
                        return Err(KclError::new_semantic(KclErrorDetails::new(
                            "User-defined types are not yet supported.".to_owned(),
                            vec![metadata.source_range],
                        )));
                    }
                };
                let (t, props) = crate::std::std_ty(std_path, &ty.name.name);
                let value = KclValue::Type {
                    value: TypeDef::RustRepr(t, props),
                    meta: vec![metadata],
                    experimental: attrs.experimental,
                };
                let name_in_mem = format!("{}{}", memory::TYPE_PREFIX, ty.name.name);
                exec_state
                    .mut_stack()
                    .add(name_in_mem.clone(), value, metadata.source_range)
                    .map_err(|_| {
                        KclError::new_semantic(KclErrorDetails::new(
                            format!("Redefinition of type {}.", ty.name.name),
                            vec![metadata.source_range],
                        ))
                    })?;

                if let ItemVisibility::Export = ty.visibility {
                    exec_state.mod_local.module_exports.push(name_in_mem);
                }
            }
            // Do nothing for primitive types, they get special treatment and their declarations are just for documentation.
            annotations::Impl::Primitive => {}
            annotations::Impl::Kcl | annotations::Impl::KclConstrainable => match &ty.definition {
                TypeDeclarationDefinition::Alias { ty: alias } => {
                    let type_def = match alias.inner.clone() {
                        Type::Named { name } => {
                            match resolve_named_type_def(&name, exec_state, self, metadata.source_range, false).await? {
                                def @ TypeDef::Enum(_) => def,
                                def => TypeDef::Alias(def.into_runtime_type()),
                            }
                        }
                        alias => TypeDef::Alias(
                            RuntimeType::from_parsed(
                                alias,
                                exec_state,
                                self,
                                metadata.source_range,
                                attrs.impl_ == annotations::Impl::KclConstrainable,
                                false,
                            )
                            .await?,
                        ),
                    };
                    if matches!(&type_def, TypeDef::Enum(_)) {
                        reject_enum_clashing_with_module(exec_state, &ty.name.name, metadata.source_range)?;
                    }
                    let value = KclValue::Type {
                        value: type_def,
                        meta: vec![metadata],
                        experimental: attrs.experimental,
                    };
                    let name_in_mem = format!("{}{}", memory::TYPE_PREFIX, ty.name.name);
                    exec_state
                        .mut_stack()
                        .add(name_in_mem.clone(), value, metadata.source_range)
                        .map_err(|_| {
                            KclError::new_semantic(KclErrorDetails::new(
                                format!("Redefinition of type {}.", ty.name.name),
                                vec![metadata.source_range],
                            ))
                        })?;

                    if let ItemVisibility::Export = ty.visibility {
                        exec_state.mod_local.module_exports.push(name_in_mem);
                    }
                }
                TypeDeclarationDefinition::Bare => {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        "User-defined types are not yet supported.".to_owned(),
                        vec![metadata.source_range],
                    )));
                }
                TypeDeclarationDefinition::Enum(decl) => {
                    // Identity is module plus declared name, so `type Color` in
                    // two function bodies of one file would be one type with two
                    // variant sets. A V1 limitation, liftable in enum v2 by
                    // giving `EnumTypeId` a declaration site.
                    if !matches!(body_type, BodyType::Root) {
                        return Err(KclError::new_semantic(KclErrorDetails::new(
                            format!(
                                "Enum declarations are only supported at the top-level of a file. Move `type {}` to the top-level.",
                                ty.name.name
                            ),
                            vec![metadata.source_range],
                        )));
                    }

                    reject_enum_clashing_with_module(exec_state, &ty.name.name, metadata.source_range)?;

                    let variants = decl.variants.iter().map(|v| v.name.name.clone()).collect();
                    let id = EnumTypeId::new(metadata.source_range.module_id(), ty.name.name.clone());
                    // Constructing the definition is the validation step: nothing
                    // below runs, so nothing reaches memory, unless every variant
                    // name is distinct.
                    let def = EnumTypeDef::new(id, variants).map_err(|duplicate| {
                        KclError::new_semantic(KclErrorDetails::new(
                            format!("Duplicate variant `{}` in enum `{}`.", duplicate.name, ty.name.name),
                            vec![
                                decl.variants[duplicate.first_index].as_source_range(),
                                decl.variants[duplicate.duplicate_index].as_source_range(),
                            ],
                        ))
                    })?;

                    let value = KclValue::Type {
                        value: TypeDef::Enum(Arc::new(def)),
                        meta: vec![metadata],
                        experimental: attrs.experimental,
                    };
                    let name_in_mem = format!("{}{}", memory::TYPE_PREFIX, ty.name.name);
                    exec_state
                        .mut_stack()
                        .add(name_in_mem.clone(), value, metadata.source_range)
                        .map_err(|_| {
                            KclError::new_semantic(KclErrorDetails::new(
                                format!("Redefinition of type {}.", ty.name.name),
                                vec![metadata.source_range],
                            ))
                        })?;

                    if let ItemVisibility::Export = ty.visibility {
                        exec_state.mod_local.module_exports.push(name_in_mem);
                    }
                }
            },
        }

        Ok(())
    }

    /// Bind the evaluated right-hand side of a variable declaration: segment
    /// tag attachment, name binding, sketch-block segment tags, feature-tree
    /// operation, and export tracking. The evaluation-free second half of
    /// variable-declaration execution, shared by both executors. Returns the
    /// bound value (which becomes the module result when this is the last
    /// Root statement).
    pub(super) fn bind_variable_declaration(
        &self,
        variable_declaration: &Node<VariableDeclaration>,
        rhs: KclValue,
        body_type: BodyType,
        exec_state: &mut ExecState,
    ) -> Result<KclValue, KclError> {
        let var_name = variable_declaration.declaration.id.name.to_string();
        let source_range = SourceRange::from(&variable_declaration.declaration.init);
        let mut rhs = rhs;

        // Attach the variable name to unsolved segments as a tag.
        // While executing the body of a sketch block, the segments
        // won't have been solved yet.
        if let KclValue::Segment { value } = &mut rhs
            && let SegmentRepr::Unsolved { segment } = &mut value.repr
        {
            segment.tag = Some(TagIdentifier {
                value: variable_declaration.declaration.id.name.clone(),
                info: Default::default(),
                meta: vec![SourceRange::from(&variable_declaration.declaration.id).into()],
            });
        }
        let rhs = rhs; // Remove mutability.

        let should_bind_name = if let Some(fn_name) = variable_declaration.declaration.init.fn_declaring_name() {
            // Declaring a function with a name, so only bind
            // the variable name if it differs from the function
            // name.
            var_name != fn_name
        } else {
            // Not declaring a function, so we should bind the
            // variable name.
            true
        };
        if should_bind_name {
            exec_state
                .mut_stack()
                .add(var_name.clone(), rhs.clone(), source_range)?;
        }

        if let Some(sketch_block_state) = exec_state.mod_local.sketch_block.as_mut()
            && let KclValue::Segment { value } = &rhs
        {
            // Add segment to mapping so that we can tag it when
            // sending to the engine.
            let segment_object_id = match &value.repr {
                SegmentRepr::Unsolved { segment } => segment.object_id,
                SegmentRepr::Solved { segment } => segment.object_id,
            };
            sketch_block_state
                .segment_tags
                .entry(segment_object_id)
                .or_insert_with(|| {
                    let id_node = &variable_declaration.declaration.id;
                    Node::new(
                        TagDeclarator {
                            name: id_node.name.clone(),
                            digest: None,
                        },
                        id_node.start,
                        id_node.end,
                        id_node.module_id,
                    )
                });
        }

        // Track operations, for the feature tree.
        // Don't track these operations if the KCL code being executed is in the stdlib,
        // because users shouldn't know about stdlib internals -- it's useless noise, to them.
        let should_show_in_feature_tree = !exec_state.mod_local.inside_stdlib && rhs.show_variable_in_feature_tree();
        if should_show_in_feature_tree {
            exec_state.push_op(Operation::VariableDeclaration {
                name: var_name.clone(),
                value: op_from_kcl_value(&rhs),
                visibility: variable_declaration.visibility,
                node_path: NodePath::placeholder(),
                source_range,
            });
        }

        // Track exports.
        if let ItemVisibility::Export = variable_declaration.visibility {
            if matches!(body_type, BodyType::Root) {
                exec_state.mod_local.module_exports.push(var_name);
            } else {
                exec_state.err(CompilationIssue::err(
                                variable_declaration.as_source_range(),
                                "Exports are only supported at the top-level of a file. Remove `export` or move it to the top-level.",
                            ));
            }
        }
        Ok(rhs)
    }

    /// Record a return statement's evaluated value as the function result
    /// (`__return`). This is the pre-KCL-3.0 `return` semantics: it
    /// deliberately does NOT stop the enclosing block -- statements after a
    /// `return` still execute, exactly like the historical behavior (see the
    /// ReturnStatement arm of exec_block); a second executed `return` is the
    /// "Multiple returns" error. Under KCL 3.0, this is never called; `return`
    /// unwinds as `Return` control flow instead. Shared by both executors.
    pub(super) fn bind_return_value(
        return_statement: &Node<ReturnStatement>,
        value: KclValue,
        exec_state: &mut ExecState,
    ) -> Result<(), KclError> {
        let metadata = Metadata::from(return_statement);
        exec_state
            .mut_stack()
            .add(memory::RETURN_NAME.to_owned(), value, metadata.source_range)
            .map_err(|_| {
                KclError::new_semantic(KclErrorDetails::new(
                    "Multiple returns from a single function.".to_owned(),
                    vec![metadata.source_range],
                ))
            })?;
        Ok(())
    }

    pub async fn open_module(
        &self,
        path: &ImportPath,
        attrs: &[Node<Annotation>],
        resolved_path: &ModulePath,
        exec_state: &mut ExecState,
        source_range: SourceRange,
    ) -> Result<ModuleId, KclError> {
        match path {
            ImportPath::Kcl { .. } => {
                exec_state.global.mod_loader.cycle_check(resolved_path, source_range)?;

                if let Some(id) = exec_state.id_for_module(resolved_path) {
                    return Ok(id);
                }

                let id = exec_state.next_module_id();
                // Add file path string to global state even if it fails to import
                exec_state.add_path_to_source_id(resolved_path.clone(), id);
                let source = resolved_path.source(&self.fs, source_range).await?;
                exec_state.add_id_to_source(id, source.clone());
                // TODO handle parsing errors properly
                let parsed = crate::parsing::parse_str(&source.source, id).parse_errs_as_err()?;
                exec_state.add_module(id, resolved_path.clone(), ModuleRepr::Kcl(parsed, None));

                Ok(id)
            }
            ImportPath::Foreign { .. } => {
                if let Some(id) = exec_state.id_for_module(resolved_path) {
                    return Ok(id);
                }

                let id = exec_state.next_module_id();
                let path = resolved_path.expect_path();
                // Add file path string to global state even if it fails to import
                exec_state.add_path_to_source_id(resolved_path.clone(), id);
                let format = super::import::format_from_annotations(attrs, path, source_range)?;
                let geom = super::import::import_foreign(path, format, exec_state, self, source_range).await?;
                exec_state.add_module(id, resolved_path.clone(), ModuleRepr::Foreign(geom, None));
                Ok(id)
            }
            ImportPath::Std { .. } => {
                if resolved_path.is_solver_module() && exec_state.mod_local.sketch_block.is_none() {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        format!("The `{resolved_path}` module is only available inside sketch blocks."),
                        vec![source_range],
                    )));
                }

                if let Some(id) = exec_state.id_for_module(resolved_path) {
                    return Ok(id);
                }

                let id = exec_state.next_module_id();
                // Add file path string to global state even if it fails to import
                exec_state.add_path_to_source_id(resolved_path.clone(), id);
                let source = resolved_path.source(&self.fs, source_range).await?;
                exec_state.add_id_to_source(id, source.clone());
                let parsed = crate::parsing::parse_str(&source.source, id)
                    .parse_errs_as_err()
                    .unwrap();
                exec_state.add_module(id, resolved_path.clone(), ModuleRepr::Kcl(parsed, None));
                Ok(id)
            }
        }
    }

    pub(super) async fn exec_module_for_items(
        &self,
        module_id: ModuleId,
        exec_state: &mut ExecState,
        source_range: SourceRange,
    ) -> Result<(EnvironmentRef, Vec<String>), KclError> {
        let path = exec_state.global.module_infos[&module_id].path.clone();
        let mut repr = exec_state.global.module_infos[&module_id].take_repr();
        // DON'T EARLY RETURN! We need to restore the module repr

        let result = match &mut repr {
            ModuleRepr::Root => Err(exec_state.circular_import_error(&path, source_range)),
            ModuleRepr::Kcl(_, Some(outcome)) => Ok((outcome.environment, outcome.exports.clone())),
            ModuleRepr::Kcl(program, cache) => self
                .exec_module_from_ast(program, module_id, &path, exec_state, source_range, PreserveMem::Normal)
                .await
                .map(|outcome| {
                    *cache = Some(outcome.clone());
                    (outcome.environment, outcome.exports)
                }),
            ModuleRepr::Foreign(geom, _) => Err(KclError::new_semantic(KclErrorDetails::new(
                "Cannot import items from foreign modules".to_owned(),
                vec![geom.source_range],
            ))),
            ModuleRepr::Dummy => unreachable!("Looking up {}, but it is still being interpreted", path),
        };

        exec_state.global.module_infos[&module_id].restore_repr(repr);
        result
    }

    async fn exec_module_for_result(
        &self,
        module_id: ModuleId,
        exec_state: &mut ExecState,
        source_range: SourceRange,
    ) -> Result<Option<KclValue>, KclError> {
        let path = exec_state.global.module_infos[&module_id].path.clone();
        let mut repr = exec_state.global.module_infos[&module_id].take_repr();
        // DON'T EARLY RETURN! We need to restore the module repr

        let result = match &mut repr {
            ModuleRepr::Root => Err(exec_state.circular_import_error(&path, source_range)),
            ModuleRepr::Kcl(_, Some(outcome)) => Ok(outcome.last_expr.clone()),
            ModuleRepr::Kcl(program, cached_items) => {
                let result = self
                    .exec_module_from_ast(program, module_id, &path, exec_state, source_range, PreserveMem::Normal)
                    .await;
                match result {
                    Ok(outcome) => {
                        let value = outcome.last_expr.clone();
                        *cached_items = Some(outcome);
                        Ok(value)
                    }
                    Err(e) => Err(e),
                }
            }
            ModuleRepr::Foreign(_, Some((imported, _))) => Ok(imported.clone()),
            ModuleRepr::Foreign(geom, cached) => {
                let caller_artifacts = std::mem::take(&mut exec_state.mod_local.artifacts);
                let result = super::import::send_to_engine(geom.clone(), exec_state, self)
                    .await
                    .map(|geom| Some(KclValue::ImportedGeometry(geom)));
                let module_artifacts = std::mem::replace(&mut exec_state.mod_local.artifacts, caller_artifacts);

                match result {
                    Ok(val) => {
                        *cached = Some((val.clone(), module_artifacts));
                        Ok(val)
                    }
                    Err(e) => {
                        // Preserve the failed command in the caller's error artifacts, matching
                        // the behavior before foreign module artifact states were isolated.
                        exec_state.mod_local.artifacts.extend(module_artifacts);
                        // Label the failure with the import so the backtrace
                        // names the foreign file, like KCL module failures do.
                        Err(e.add_import_location(&path.import_name(), source_range))
                    }
                }
            }
            ModuleRepr::Dummy => unreachable!(),
        };

        exec_state.global.module_infos[&module_id].restore_repr(repr);

        result
    }

    pub async fn exec_module_from_ast(
        &self,
        program: &Node<Program>,
        module_id: ModuleId,
        path: &ModulePath,
        exec_state: &mut ExecState,
        source_range: SourceRange,
        preserve_mem: PreserveMem,
    ) -> Result<ModuleExecutionOutcome, KclError> {
        exec_state.global.mod_loader.enter_module(path);
        let result = self
            .exec_module_body(program, exec_state, preserve_mem, module_id, path)
            .await;
        exec_state.global.mod_loader.leave_module(path, source_range)?;

        // TODO: ModuleArtifactState is getting dropped here when there's an
        // error.  Should we propagate it for non-root modules?
        result.map_err(|(err, _, _)| {
            match err {
                KclError::ImportCycle { .. } => {
                    // It was an import cycle.  Keep the original message.
                    err.override_source_ranges(vec![source_range])
                }
                // The module loaded successfully, so preserve execution errors
                // exactly as they occurred inside it. Rewrapping them here loses
                // the error kind, structured fields, and imported-file location.
                _ => err.add_import_location(&path.import_name(), source_range),
            }
        })
    }

    /// Resolve a name to its value, running the module body first when the name
    /// refers to a module. Flat (module execution happens in its own fresh
    /// root); shared by both executors.
    pub(super) async fn resolve_name_for_eval(
        &self,
        name: &Node<Name>,
        metadata: &Metadata,
        exec_state: &mut ExecState,
    ) -> Result<KclValue, KclError> {
        let value = name.get_result(exec_state, self).await?;
        if let KclValue::Module { value: module_id, meta } = value {
            Ok(self
                .exec_module_for_result(module_id, exec_state, metadata.source_range)
                .await?
                .unwrap_or_else(|| {
                    exec_state.warn(
                        CompilationIssue::err(
                            metadata.source_range,
                            "Imported module has no return value. The last statement of the module must be an expression, usually the Solid.",
                        ),
                        annotations::WARN_MOD_RETURN_VALUE,
                    );

                    let mut new_meta = vec![metadata.to_owned()];
                    new_meta.extend(meta);
                    KclValue::KclNone {
                        value: Default::default(),
                        meta: new_meta,
                    }
                }))
        } else {
            Ok(value)
        }
    }

    #[async_recursion]
    pub(crate) async fn execute_expr<'a: 'async_recursion>(
        &self,
        init: &Expr,
        exec_state: &mut ExecState,
        metadata: &Metadata,
        annotations: &[Node<Annotation>],
        statement_kind: StatementKind<'a>,
    ) -> Result<KclValueControlFlow, KclError> {
        let item = match init {
            Expr::None(none) => KclValue::from(none).continue_(),
            Expr::Literal(literal) => KclValue::from_literal((**literal).clone(), exec_state).continue_(),
            Expr::TagDeclarator(tag) => tag.execute(exec_state).await?.continue_(),
            Expr::Name(name) => self
                .resolve_name_for_eval(name, metadata, exec_state)
                .await?
                .continue_(),
            Expr::BinaryExpression(binary_expression) => binary_expression.get_result(exec_state, self).await?,
            Expr::FunctionExpression(function_expression) => self
                .create_function_closure(function_expression, annotations, metadata, statement_kind, exec_state)
                .await?
                .continue_(),
            Expr::CallExpressionKw(call_expression) => call_expression.execute(exec_state, self).await?,
            Expr::PipeExpression(pipe_expression) => pipe_expression.get_result(exec_state, self).await?,
            Expr::PipeSubstitution(pipe_substitution) => match statement_kind {
                StatementKind::Declaration { name } => {
                    let message = format!(
                        "you cannot declare variable {name} as %, because % can only be used in function calls"
                    );

                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        message,
                        vec![pipe_substitution.into()],
                    )));
                }
                StatementKind::Expression => match exec_state.mod_local.pipe_value.clone() {
                    Some(x) => x.continue_(),
                    None => {
                        return Err(KclError::new_semantic(KclErrorDetails::new(
                            "cannot use % outside a pipe expression".to_owned(),
                            vec![pipe_substitution.into()],
                        )));
                    }
                },
            },
            Expr::ArrayExpression(array_expression) => array_expression.execute(exec_state, self).await?,
            Expr::ArrayRangeExpression(range_expression) => range_expression.execute(exec_state, self).await?,
            Expr::ObjectExpression(object_expression) => object_expression.execute(exec_state, self).await?,
            Expr::MemberExpression(member_expression) => member_expression.get_result(exec_state, self).await?,
            Expr::UnaryExpression(unary_expression) => unary_expression.get_result(exec_state, self).await?,
            Expr::IfExpression(expr) => expr.get_result(exec_state, self).await?,
            Expr::LabelledExpression(expr) => {
                let value_cf = self
                    .execute_expr(&expr.expr, exec_state, metadata, &[], statement_kind)
                    .await?;
                let value = control_continue!(value_cf);
                exec_state
                    .mut_stack()
                    .add(expr.label.name.clone(), value.clone(), init.into())?;
                // TODO this lets us use the label as a variable name, but not as a tag in most cases
                value.continue_()
            }
            Expr::AscribedExpression(expr) => expr.get_result(exec_state, self).await?,
            Expr::SketchBlock(expr) => expr.get_result(exec_state, self).await?,
            Expr::SketchVar(expr) => expr.get_result(exec_state, self).await?.continue_(),
        };
        Ok(item)
    }

    /// Evaluate a single expression on whichever executor is active, as a
    /// fresh root. For bounded internal evaluations (e.g. GD&T's constant
    /// plane lookup).
    pub(crate) async fn eval_expr_fresh_root(
        &self,
        expr: &Expr,
        exec_state: &mut ExecState,
        metadata: &Metadata,
    ) -> Result<KclValueControlFlow, KclError> {
        if self.is_machine_executor() {
            return crate::execution::machine::run_expr(self, expr, exec_state, metadata).await;
        }
        self.execute_expr(expr, exec_state, metadata, &[], StatementKind::Expression)
            .await
    }

    /// Create the closure value for a function expression, including the
    /// recursive-closure placeholder fixup and binding a named `fn name() {}`
    /// in the current scope. Flat; shared by both executors.
    pub(super) async fn create_function_closure(
        &self,
        function_expression: &crate::parsing::ast::types::BoxNode<FunctionExpression>,
        annotations: &[Node<Annotation>],
        metadata: &Metadata,
        statement_kind: StatementKind<'_>,
        exec_state: &mut ExecState,
    ) -> Result<KclValue, KclError> {
        let attrs = annotations::get_fn_attrs(annotations, metadata.source_range)?;
        let experimental = attrs
            .as_ref()
            .map(|a| a.experimental)
            // Use the default for the field, not the bool type.
            .unwrap_or_else(|| FnAttrs::default().experimental);

        // Check the KCL @(feature_tree = ) annotation.
        let include_in_feature_tree = attrs
            .as_ref()
            .map(|a| a.include_in_feature_tree)
            // Use the default for the field, not the bool type.
            .unwrap_or_else(|| FnAttrs::default().include_in_feature_tree);
        let (mut closure, placeholder_env_ref) = if let Some(attrs) = attrs
            && (attrs.impl_ == annotations::Impl::Rust
                || attrs.impl_ == annotations::Impl::RustConstrainable
                || attrs.impl_ == annotations::Impl::RustConstraint)
        {
            if let ModulePath::Std { value: std_path } = &exec_state.mod_local.path {
                let (func, props) = crate::std::std_fn(std_path, statement_kind.expect_name());
                (
                    KclValue::Function {
                        value: Box::new(FunctionSource::rust(func, function_expression.clone(), props, attrs)),
                        meta: vec![metadata.to_owned()],
                    },
                    None,
                )
            } else {
                return Err(KclError::new_semantic(KclErrorDetails::new(
                    "Rust implementation of functions is restricted to the standard library".to_owned(),
                    vec![metadata.source_range],
                )));
            }
        } else {
            let std_props = function_expression
                .name_str()
                .and_then(|name| exec_state.mod_local.path.build_std_fully_qualified_name(name))
                .map(|name| StdFnProps::default(&name));
            // Snapshotting memory here is crucial for semantics so that we close
            // over variables. Variables defined lexically later shouldn't
            // be available to the function body.
            let (env_ref, placeholder_env_ref) = if function_expression.name.is_some() {
                // Recursive function needs a snapshot that includes
                // itself.
                let dummy = EnvironmentRef::dummy();
                (dummy, Some(dummy))
            } else {
                (exec_state.mut_stack().snapshot()?, None)
            };
            (
                KclValue::Function {
                    value: Box::new(FunctionSource::kcl(
                        function_expression.clone(),
                        env_ref,
                        KclFunctionSourceParams {
                            std_props,
                            experimental,
                            include_in_feature_tree,
                        },
                    )),
                    meta: vec![metadata.to_owned()],
                },
                placeholder_env_ref,
            )
        };

        // Resolve the signature's type names now, in the scope where
        // the declaration is written. Call sites consume the stored
        // resolutions and never look type names up themselves.
        if let KclValue::Function { value, .. } = &mut closure {
            value.resolve_signature_types(exec_state, self).await?;
        }

        // If the function expression has a name, i.e. `fn name() {}`,
        // bind it in the current scope.
        if let Some(fn_name) = &function_expression.name {
            // If we used a placeholder env ref for recursion, fix it up
            // with the name recursively bound so that it's available in
            // the function body.
            if let Some(placeholder_env_ref) = placeholder_env_ref {
                closure = exec_state.mut_stack().add_recursive_closure(
                    fn_name.name.to_owned(),
                    closure,
                    placeholder_env_ref,
                    metadata.source_range,
                )?;
            } else {
                // Regular non-recursive binding.
                exec_state
                    .mut_stack()
                    .add(fn_name.name.clone(), closure.clone(), metadata.source_range)?;
            }
        }

        Ok(closure)
    }
}

/// The head of a `Color::Red` path is looked up both as a module and as an enum,
/// so one scope must not bind a module and an enum under the same name. Reporting
/// the clash where the second name is introduced keeps every `X::y` use site
/// unambiguous, so no check is needed at the use site.
///
/// Type aliases that resolve to enums participate in this rule because they can
/// head a `::` path. Other aliases and bare types may continue to share a name
/// with a module.
fn module_enum_clash(name: &str, source_range: SourceRange) -> KclError {
    KclError::new_semantic(KclErrorDetails::new(
        format!(
            "An enum and a module cannot share the name `{name}` in the same scope, because `{name}::x` would be ambiguous. Rename one of them."
        ),
        vec![source_range],
    ))
}

/// Call before binding an enum under `name`.
fn reject_enum_clashing_with_module(
    exec_state: &ExecState,
    name: &str,
    source_range: SourceRange,
) -> Result<(), KclError> {
    let key = format!("{}{}", memory::MODULE_PREFIX, name);
    if !exec_state.stack().cur_frame_contains(&key)? {
        return Ok(());
    }

    Err(module_enum_clash(name, source_range))
}

/// Call before binding a module under `name`. The mirror of
/// [`reject_enum_clashing_with_module`].
fn reject_module_clashing_with_enum(
    exec_state: &ExecState,
    name: &str,
    source_range: SourceRange,
) -> Result<(), KclError> {
    let key = format!("{}{}", memory::TYPE_PREFIX, name);
    if !exec_state.stack().cur_frame_contains(&key)? {
        return Ok(());
    }

    let Ok(KclValue::Type {
        value: TypeDef::Enum(_),
        ..
    }) = exec_state.stack().get(&key, source_range)
    else {
        return Ok(());
    };

    Err(module_enum_clash(name, source_range))
}

/// Builds the error for comparing values of two different enum types.
fn different_enums_err(left: &EnumValue, right: &EnumValue, source_range: SourceRange) -> KclError {
    let left_name = left.enum_id().declared_name();
    let right_name = right.enum_id().declared_name();

    let message = if left_name == right_name {
        // Identity is the declaration, so two enums can share a name and still be
        // different types. Naming both would read as a mistake in the message.
        format!(
            "Cannot compare two different enums that are both named `{left_name}`. They come from separate declarations."
        )
    } else {
        format!("Cannot compare enum `{left_name}` with enum `{right_name}`. They are different types.")
    };

    KclError::new_semantic(KclErrorDetails::new(message, vec![source_range]))
}

/// Builds the error for a name that resolves to a type where a value is needed,
/// such as `x = Color`.
///
/// Returns `None` when no type of that name is in scope, which leaves the
/// caller's "is not defined" error in place.
fn type_used_as_value(exec_state: &ExecState, name: &Node<Identifier>) -> Option<KclError> {
    let key = format!("{}{}", memory::TYPE_PREFIX, name.name);
    let KclValue::Type { value: def, .. } = exec_state.stack().get(&key, name.as_source_range()).ok()? else {
        return None;
    };

    // The suggestion uses the name as written, which may be an import alias, so
    // that it can be pasted into the file that produced the error.
    let suggestion = match &def {
        TypeDef::Enum(def) => def
            .variants()
            .first()
            .map(|variant| format!(" Use one of its variants, such as `{}::{variant}`.", name.name))
            .unwrap_or_default(),
        _ => String::new(),
    };

    Some(KclError::new_semantic(KclErrorDetails::new(
        format!("`{}` is a type, not a value.{suggestion}", name.name),
        name.as_source_ranges(),
    )))
}

enum EnumPathHead {
    Enum(Arc<EnumTypeDef>),
    NonEnumType,
}

/// Classifies the type named by a `::` path segment: `Color` in both
/// `Color::Red` and `colors::Color::Red`.
///
/// A non-enum type is retained until module lookup has also failed because a
/// type alias and a module may share a name. The module remains the valid path
/// head in that case.
fn enum_named_by_segment(
    exec_state: &ExecState,
    segment: &Node<Identifier>,
    within: Option<&(EnvironmentRef, Vec<String>)>,
) -> Option<EnumPathHead> {
    match type_value_named_by_segment(exec_state, segment, within)? {
        KclValue::Type {
            value: TypeDef::Enum(def),
            ..
        } => Some(EnumPathHead::Enum(def)),
        KclValue::Type { .. } => Some(EnumPathHead::NonEnumType),
        _ => None,
    }
}

fn non_enum_type_in_path(segment: &Node<Identifier>) -> KclError {
    KclError::new_semantic(KclErrorDetails::new(
        format!(
            "`{}` is a type that does not resolve to an enum, so it cannot be used as the head of a `::` path.",
            segment.name
        ),
        segment.as_source_ranges(),
    ))
}

/// `Red` in `Color::Red`.
fn enum_variant_value(
    def: Arc<EnumTypeDef>,
    variant: &Node<Identifier>,
    exec_state: &mut ExecState,
) -> Result<KclValue, KclError> {
    let enum_name = def.id().declared_name();

    if !def.has_variant(&variant.name) {
        let known = if def.variants().is_empty() {
            format!("Enum `{enum_name}` has no variants")
        } else {
            format!("Its variants are: {}", def.variants().join(", "))
        };

        return Err(KclError::new_semantic(KclErrorDetails::new(
            format!("`{}` is not a variant of enum `{enum_name}`. {known}.", variant.name),
            variant.as_source_ranges(),
        )));
    }

    // Every V1 enum is experimental, not only those with an annotation, so this
    // call is unconditional. `warn_experimental` reads the setting of the module
    // being executed and does nothing when that setting is `allow`, so an enum
    // imported from a permissive module is still reported in a consumer that has
    // not opted in. Declarations are gated during parsing; type positions by
    // `RuntimeType::from_alias`.
    exec_state.warn_experimental(&format!("the enum `{enum_name}`"), variant.as_source_range());

    // The value holds the declaration itself, so its identity is read off that
    // declaration and can never be rebuilt from a name. A later enum v2 adding a
    // declaration site to `EnumTypeId` therefore changes nothing here.
    Ok(KclValue::Enum {
        value: Box::new(EnumValue::new(
            def,
            variant.name.clone(),
            vec![Metadata {
                source_range: variant.as_source_range(),
            }],
        )),
    })
}

/// Glob imports copy exported keys verbatim, prefix included, so which namespace
/// an incoming key lands in has to be read back off the key itself.
fn reject_glob_import_clash(
    exec_state: &ExecState,
    key: &str,
    item: &KclValue,
    source_range: SourceRange,
) -> Result<(), KclError> {
    if let Some(name) = key.strip_prefix(memory::MODULE_PREFIX) {
        return reject_module_clashing_with_enum(exec_state, name, source_range);
    }

    if let Some(name) = key.strip_prefix(memory::TYPE_PREFIX)
        && matches!(
            item,
            KclValue::Type {
                value: TypeDef::Enum(_),
                ..
            }
        )
    {
        return reject_enum_clashing_with_module(exec_state, name, source_range);
    }

    Ok(())
}

/// When executing in sketch mode, whether we should skip executing this
/// expression.
pub(super) fn sketch_mode_should_skip(expr: &Expr) -> bool {
    fn contains_edited_sketch_block(node: crate::walk::Node<'_>) -> bool {
        if let crate::walk::Node::SketchBlock(sketch_block) = node {
            return sketch_block.is_being_edited;
        }
        node.children().into_iter().any(contains_edited_sketch_block)
    }

    !contains_edited_sketch_block(expr.into())
}

/// If the error is about an undefined name, and that name matches the name being defined,
/// make the error message more specific.
fn var_in_own_ref_err(e: KclError, being_declared: &Option<String>) -> KclError {
    let KclError::UndefinedValue { name, mut details } = e else {
        return e;
    };
    // TODO after June 26th: replace this with a let-chain,
    // which will be available in Rust 1.88
    // https://rust-lang.github.io/rfcs/2497-if-let-chains.html
    if let (Some(name0), Some(name1)) = (&being_declared, &name)
        && name0 == name1
    {
        details.message = format!(
            "You can't use `{name0}` because you're currently trying to define it. Use a different variable here instead."
        );
    }
    KclError::UndefinedValue { details, name }
}

impl Node<AscribedExpression> {
    #[async_recursion]
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        let metadata = Metadata {
            source_range: SourceRange::from(self),
        };
        let result = ctx
            .execute_expr(&self.expr, exec_state, &metadata, &[], StatementKind::Expression)
            .await?;
        let result = control_continue!(result);
        apply_ascription(&result, &self.ty, exec_state, ctx, self.into())
            .await
            .map(KclValue::continue_)
    }
}

impl Node<SketchBlock> {
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        if exec_state.mod_local.sketch_block.is_some() {
            // Disallow nested sketch blocks for now.
            return Err(KclError::new_semantic(KclErrorDetails::new(
                "Cannot execute a sketch block from within another sketch block".to_owned(),
                vec![SourceRange::from(self)],
            )));
        }

        let range = SourceRange::from(self);

        // Evaluate arguments.
        let (sketch_id, sketch_surface) = match self.exec_arguments(exec_state, ctx).await {
            Ok(x) => x,
            Err(cf_error) => match cf_error {
                // Control flow needs to return early.
                EarlyReturn::Value(cf_value) => return Ok(cf_value),
                EarlyReturn::Error(err) => return Err(err),
            },
        };
        let sketch_block_artifact_id = self.scene_setup(sketch_id, &sketch_surface, exec_state)?;

        let (return_result, variables, sketch_block_state) = {
            // Don't early return until the stack frame is popped!
            self.prep_mem(exec_state.mut_stack().snapshot()?, exec_state)?;

            // Track that we're executing a sketch block.
            let initial_sketch_block_state = {
                SketchBlockState {
                    sketch_id: Some(sketch_id),
                    ..Default::default()
                }
            };

            let original_value = exec_state.mod_local.sketch_block.replace(initial_sketch_block_state);

            // When executing the body of the sketch block, we no longer want to
            // skip any code.
            let original_sketch_mode = std::mem::replace(&mut exec_state.mod_local.sketch_mode, false);

            // Load `sketch2::*` into the sketch block's parent scope, so calls
            // like `line(...)` resolve to sketch2 functions. Then execute the
            // user body in a child scope, so these aliases aren't included in
            // the returned sketch object.
            let (result, block_variables) = match self.load_sketch2_into_current_scope(exec_state, ctx, range).await {
                Ok(()) => {
                    let parent = exec_state.mut_stack().snapshot()?;
                    exec_state.mut_stack().push_new_env_for_call(parent)?;
                    let result = ctx.exec_block(&self.body, exec_state, BodyType::Block).await;
                    let (result, block_variables) = match exec_state.stack().find_all_in_current_env() {
                        Ok(block_variables) => (result, block_variables.into_iter().collect::<IndexMap<_, _>>()),
                        Err(err) => (Err(err), IndexMap::new()),
                    };
                    let result = match exec_state.mut_stack().pop_env() {
                        Ok(_) => result,
                        Err(err) => Err(err),
                    };
                    (result, block_variables)
                }
                Err(err) => (Err(err), IndexMap::new()),
            };

            exec_state.mod_local.sketch_mode = original_sketch_mode;

            let sketch_block_state = std::mem::replace(&mut exec_state.mod_local.sketch_block, original_value);

            // Pop the scope used for sketch2 aliases.
            let result = match exec_state.mut_stack().pop_env() {
                Ok(_) => result,
                Err(err) => Err(err),
            };

            (result, block_variables, sketch_block_state)
        };

        // Propagate errors.
        let return_control_flow = return_result?;
        // If the sketch block body exited early (e.g. via `exit()`), propagate
        // the exit so that the rest of the program terminates instead of only
        // ending this sketch block. Without this, execution would fall through,
        // solve the partial sketch, and continue on to later statements.
        if let Some(control_flow) = return_control_flow
            && control_flow.is_some_return()
        {
            // Balance the GroupBegin operation pushed above so the feature tree
            // stays well-formed.
            exec_state.push_op(Operation::GroupEnd);
            return Ok(control_flow);
        }
        let Some(sketch_block_state) = sketch_block_state else {
            debug_assert!(false, "Sketch block state should still be set to Some from just above");
            return Err(internal_err(
                "Sketch block state should still be set to Some from just above",
                self,
            ));
        };
        let return_value = self
            .finalize_sketch_block(
                sketch_id,
                &sketch_surface,
                sketch_block_artifact_id,
                variables,
                sketch_block_state,
                exec_state,
                ctx,
            )
            .await?;
        Ok(if self.is_being_edited {
            // When the sketch block is being edited, we exit the program
            // immediately.
            return_value.exit()
        } else {
            return_value.continue_()
        })
    }

    /// Executes the arguments of the sketch block and returns the sketch ID and
    /// surface. The surface is the `on` argument, which is basically a Plane or
    /// Face.
    ///
    /// In sketch mode, the execution cache is used to look up the sketch
    /// surface.
    ///
    /// The sketch ID is generated in either case so that it's stable. But only
    /// a placeholder scene object is created for it.
    async fn exec_arguments(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<(ObjectId, SketchSurface), EarlyReturn> {
        if !exec_state.sketch_mode() {
            // Evaluate arguments.
            //
            // Sketch mode only executes the sketch block body. Arguments must
            // be evaluated in engine execution so that things like Planes and
            // Faces can be created in the engine.
            let mut labeled = IndexMap::new();
            for labeled_arg in &self.arguments {
                let source_range = SourceRange::from(labeled_arg.arg.clone());
                let metadata = Metadata { source_range };
                let value_cf = ctx
                    .execute_expr(&labeled_arg.arg, exec_state, &metadata, &[], StatementKind::Expression)
                    .await?;
                let value = early_return!(value_cf);
                let arg = Arg::new(value, source_range);
                match &labeled_arg.label {
                    Some(label) => {
                        labeled.insert(label.name.clone(), arg);
                    }
                    None => {
                        let name = labeled_arg.arg.ident_name();
                        if let Some(name) = name {
                            labeled.insert(name.to_owned(), arg);
                        } else {
                            return Err(KclError::new_semantic(KclErrorDetails::new(
                                "Arguments to sketch blocks must be either labeled or simple identifiers".to_owned(),
                                vec![SourceRange::from(&labeled_arg.arg)],
                            ))
                            .into());
                        }
                    }
                }
            }
            self.finish_arguments_after_eval(labeled, exec_state, ctx).await
        } else {
            self.arguments_from_cache(exec_state)
        }
    }

    /// The evaluation-free tail of sketch-block argument handling: validate
    /// the arguments, resolve the `on` surface, ensure it exists in the
    /// engine, and mint the stable sketch id. Shared by both executors.
    pub(super) async fn finish_arguments_after_eval(
        &self,
        labeled: IndexMap<String, Arg>,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<(ObjectId, SketchSurface), EarlyReturn> {
        let range = SourceRange::from(self);
        let mut args = Args::new_no_args(
            range,
            self.node_path.clone(),
            ctx.clone(),
            Some(SketchBlock::CALLEE_NAME.to_owned()),
        );
        args.labeled = labeled;

        // Report any arguments that aren't valid sketch block parameters.
        // This is non-fatal so that the rest of the block still executes,
        // matching how unexpected keyword arguments are handled for
        // function calls.
        //
        // Checking arguments should be done after evaluating them, the same
        // order as if we were calling a function.
        self.check_for_unexpected_arguments(&args, exec_state)?;

        let arg_on_value: KclValue =
            args.get_kw_arg(SKETCH_BLOCK_PARAM_ON, &RuntimeType::sketch_or_surface(), exec_state)?;

        let Some(arg_on) = SketchOrSurface::from_kcl_val(&arg_on_value) else {
            let message = "The `on` argument to a sketch block must be convertible to a sketch or surface.".to_owned();
            debug_assert!(false, "{message}");
            return Err(KclError::new_semantic(KclErrorDetails::new(message, vec![range])).into());
        };
        let mut sketch_surface = arg_on.into_sketch_surface();

        // Ensure that the plane has an ObjectId. Always create an Object so
        // that we're consistent with IDs.
        match &mut sketch_surface {
            SketchSurface::Plane(plane) => {
                // Ensure that it's been created in the engine.
                ensure_sketch_plane_in_engine(plane, exec_state, ctx, range, self.node_path.clone()).await?;
            }
            SketchSurface::Face(_) => {
                // All faces should already be created in the engine.
            }
        }

        // Generate an ID for the sketch block. This must be done after
        // arguments so that we get the same result when the arguments are
        // cached. This must be done before the sketch block body so that no
        // matter how many IDs are generated due to objects in the body, the
        // sketch ID is always stable.
        let sketch_id = exec_state.next_object_id();
        exec_state.add_placeholder_scene_object(sketch_id, range, self.node_path.clone());
        let on_cache_name = sketch_on_cache_name(sketch_id);
        // Store in memory so that it's cached.
        exec_state.mut_stack().add(on_cache_name, arg_on_value, range)?;

        Ok((sketch_id, sketch_surface))
    }

    /// Sketch-mode path: arguments cannot be re-evaluated, so look the `on`
    /// surface up from the execution cache. Flat; shared by both executors.
    pub(super) fn arguments_from_cache(
        &self,
        exec_state: &mut ExecState,
    ) -> Result<(ObjectId, SketchSurface), EarlyReturn> {
        let range = SourceRange::from(self);
        {
            // In sketch mode, we can't re-evaluate arguments. Instead, look
            // them up from cache.

            // Generate an ID for the sketch block. This must be done before the
            // sketch block body so that no matter how many IDs are generated
            // due to objects in the body, the sketch ID is always stable.
            let sketch_id = exec_state.next_object_id();
            exec_state.add_placeholder_scene_object(sketch_id, range, self.node_path.clone());
            let on_cache_name = sketch_on_cache_name(sketch_id);
            let arg_on_value = exec_state.stack().get_owned(&on_cache_name, range)?;

            let Some(arg_on) = SketchOrSurface::from_kcl_val(&arg_on_value) else {
                let message =
                    "The `on` argument to a sketch block must be convertible to a sketch or surface.".to_owned();
                debug_assert!(false, "{message}");
                return Err(KclError::new_semantic(KclErrorDetails::new(message, vec![range])).into());
            };
            let mut sketch_surface = arg_on.into_sketch_surface();

            // Ensure that the plane has an ObjectId. Always create an Object so
            // that we're consistent with IDs.
            if sketch_surface.object_id().is_none() {
                // Look up the last object. Since this is where we would have
                // created it in real execution, it will be the last object.
                let Some(last_object) = exec_state.mod_local.artifacts.scene_objects.last() else {
                    return Err(internal_err(
                        "In sketch mode, the `on` plane argument must refer to an existing plane object.",
                        range,
                    )
                    .into());
                };
                sketch_surface.set_object_id(last_object.id);
            }

            Ok((sketch_id, sketch_surface))
        }
    }

    /// Create the sketch scene object and sketch-block artifact, and open
    /// the feature-tree group. Flat; shared by both executors.
    pub(super) fn scene_setup(
        &self,
        sketch_id: ObjectId,
        sketch_surface: &SketchSurface,
        exec_state: &mut ExecState,
    ) -> Result<ArtifactId, KclError> {
        let range = SourceRange::from(self);
        let on_object_id = if let Some(object_id) = sketch_surface.object_id() {
            object_id
        } else {
            let message = "The `on` argument should have an object after ensure_sketch_plane_in_engine".to_owned();
            debug_assert!(false, "{message}");
            return Err(internal_err(message, range));
        };
        let sketch_ctor_on = sketch_on_frontend_plane(&self.arguments, on_object_id);
        let sketch_block_artifact_id = {
            use crate::execution::CodeRef;
            use crate::execution::SketchBlock;
            use crate::front::Plane;
            use crate::front::SourceRef;

            let on_object = exec_state.mod_local.artifacts.scene_object_by_id(on_object_id);

            // Get the plane artifact ID so that we can do an exclusive borrow.
            let plane_artifact_id = on_object.map(|object| object.artifact_id);
            let plane_info = match &sketch_surface {
                SketchSurface::Plane(plane) => Some(super::artifact::artifact_plane_info(&plane.info)),
                SketchSurface::Face(_) => None,
            };

            let standard_plane = match &sketch_ctor_on {
                Plane::Default(plane) => Some(*plane),
                Plane::Object(_) | Plane::PrimitiveFace(_) => None,
            };

            let artifact_id = ArtifactId::from(exec_state.next_uuid());
            // Label the sketch with the name of the variable whose right-hand
            // side is being evaluated. This function runs before the sketch
            // body executes, so for `mySketch = sketch(on = XY) { ... }`,
            // `being_declared` still holds `mySketch` rather than a name
            // declared inside the body.
            //
            // The label is the nearest enclosing declaration, which is not
            // always the sketch's own name:
            // - `part = extrude(sketch(on = XY) { ... }, length = 10)` labels
            //   the sketch `part`.
            // - A sketch constructed inside a function body and returned takes
            //   the name of the declaration in progress at the call site, so
            //   two calls to that function can produce the same label.
            // - A sketch written as an expression statement has no declaration
            //   in progress, so its label is the empty string.
            let label = exec_state.mod_local.being_declared.clone().unwrap_or_default();
            // Create the sketch scene object and replace its placeholder.
            let sketch_scene_object = Object {
                id: sketch_id,
                kind: ObjectKind::Sketch(crate::frontend::sketch::Sketch {
                    args: crate::front::SketchCtor { on: sketch_ctor_on },
                    plane: on_object_id,
                    segments: Default::default(),
                    constraints: Default::default(),
                }),
                label,
                comments: Default::default(),
                artifact_id,
                source: SourceRef::new(self.into(), self.node_path.clone()),
            };
            exec_state.set_scene_object(sketch_scene_object);

            // Create and add the sketch block artifact.
            exec_state.add_artifact(Artifact::SketchBlock(SketchBlock {
                id: artifact_id,
                standard_plane,
                plane_id: plane_artifact_id,
                plane_info,
                // Fill this in later once we create the path. We can't just add
                // the artifact later because order relative to constraint
                // artifacts is significant.
                path_id: None,
                code_ref: CodeRef::placeholder(range),
                sketch_id,
            }));

            exec_state.push_op(Operation::GroupBegin {
                group: Group::SketchBlock { sketch_id },
                node_path: NodePath::placeholder(),
                source_range: range,
            });
            artifact_id
        };
        Ok(sketch_block_artifact_id)
    }

    /// Solve constraints, send segments to the engine, update artifacts and
    /// scene objects, close the feature-tree group, and build the sketch's
    /// result object. Flat (the body has already executed); shared by both
    /// executors.
    #[allow(clippy::too_many_arguments)]
    pub(super) async fn finalize_sketch_block(
        &self,
        sketch_id: ObjectId,
        sketch_surface: &SketchSurface,
        sketch_block_artifact_id: ArtifactId,
        variables: IndexMap<String, KclValue>,
        mut sketch_block_state: SketchBlockState,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValue, KclError> {
        let range = SourceRange::from(self);
        // Translate sketch variables and constraints to solver input.
        let constraints = sketch_block_state
            .solver_constraints
            .iter()
            .cloned()
            .map(ezpz::ConstraintRequest::highest_priority)
            .chain(
                // Optional constraints have a lower priority.
                sketch_block_state
                    .solver_optional_constraints
                    .iter()
                    .cloned()
                    .map(|c| ezpz::ConstraintRequest::new(c, 1)),
            )
            .collect::<Vec<_>>();
        let initial_guesses = sketch_block_state
            .sketch_vars
            .iter()
            .map(|v| {
                let Some(sketch_var) = v.as_sketch_var() else {
                    return Err(internal_err("Expected sketch variable", self));
                };
                let constraint_id = sketch_var.id.to_constraint_id(range)?;
                // Normalize units.
                let number_value = KclValue::Number {
                    value: sketch_var.initial_value,
                    ty: sketch_var.ty,
                    meta: sketch_var.meta.clone(),
                };
                let initial_guess_value = normalize_to_solver_distance_unit(
                    &number_value,
                    v.into(),
                    exec_state,
                    "sketch variable initial value",
                )?;
                let initial_guess = if let Some(n) = initial_guess_value.as_ty_f64() {
                    n.n
                } else {
                    let message = format!(
                        "Expected number after coercion, but found {}",
                        initial_guess_value.human_friendly_type()
                    );
                    debug_assert!(false, "{}", &message);
                    return Err(internal_err(message, self));
                };
                Ok((constraint_id, initial_guess))
            })
            .collect::<Result<Vec<_>, KclError>>()?;
        // Solve constraints.
        let config = ezpz::Config::default()
            .with_max_iterations(50)
            .with_convergence_tolerance(SOLVER_CONVERGENCE_TOLERANCE);
        let solve_result = if exec_state.mod_local.freedom_analysis {
            ezpz::solve_analysis(&constraints, initial_guesses.clone(), config).map(|outcome| {
                let freedom_analysis = FreedomAnalysis::from_ezpz_analysis(outcome.analysis, constraints.len());
                (outcome.outcome, Some(freedom_analysis))
            })
        } else {
            ezpz::solve(&constraints, initial_guesses.clone(), config).map(|outcome| (outcome, None))
        };
        // Build a combined list of all constraints (regular + optional) for conflict detection
        let num_required_constraints = sketch_block_state.solver_constraints.len();
        let all_constraints: Vec<ezpz::Constraint> = sketch_block_state
            .solver_constraints
            .iter()
            .cloned()
            .chain(sketch_block_state.solver_optional_constraints.iter().cloned())
            .collect();

        let (solve_outcome, solve_analysis) = match solve_result {
            Ok((solved, freedom)) => {
                if solved
                    .final_values()
                    .iter()
                    .any(|number| number.is_infinite() || number.is_nan())
                {
                    return Err(KclError::new_internal(KclErrorDetails::new(
                        "KCL's 2D constraint solver returned an invalid number".to_owned(),
                        vec![SourceRange::from(self)],
                    )));
                }
                let outcome = Solved::from_ezpz_outcome(solved, &all_constraints, num_required_constraints);
                if !outcome.converged {
                    exec_state.warn(
                        CompilationIssue::err(range, "Constraint solver failed to find a solution".to_owned()),
                        annotations::WARN_SOLVER,
                    );
                }
                (outcome, freedom)
            }
            Err(failure) => {
                match &failure.error {
                    NonLinearSystemError::FaerMatrix { .. }
                    | NonLinearSystemError::Faer { .. }
                    | NonLinearSystemError::FaerSolve { .. }
                    | NonLinearSystemError::FaerSvd(..) => {
                        // Constraint solver failed to find a solution. Build a
                        // solution that is the initial guesses.
                        exec_state.warn(
                            CompilationIssue::err(range, "Internal error in constraint solver".to_owned()),
                            annotations::WARN_SOLVER,
                        );
                        let final_values = initial_guesses.iter().map(|(_, v)| *v).collect::<Vec<_>>();
                        (
                            Solved {
                                final_values,
                                iterations: Default::default(),
                                warnings: failure.warnings,
                                priority_solved: Default::default(),
                                variables_in_conflicts: Default::default(),
                                unsatisfied_directional_constraints: Default::default(),
                                converged: false,
                            },
                            None,
                        )
                    }
                    NonLinearSystemError::EmptySystemNotAllowed
                    | NonLinearSystemError::WrongNumberGuesses { .. }
                    | NonLinearSystemError::MissingGuess { .. }
                    | NonLinearSystemError::NotFound(..) => {
                        // These indicate something's gone wrong in KCL or ezpz,
                        // it's not a user error. We should investigate this.
                        #[cfg(target_arch = "wasm32")]
                        web_sys::console::error_1(
                            &format!("Internal error from constraint solver: {}", failure.error).into(),
                        );
                        return Err(internal_err(
                            format!("Internal error from constraint solver: {}", failure.error),
                            self,
                        ));
                    }
                    _ => {
                        // Catch all error case so that it's not a breaking change to publish new errors.
                        return Err(internal_err(
                            format!("Error from constraint solver: {}", failure.error),
                            self,
                        ));
                    }
                }
            }
        };
        // Propagate warnings.
        for warning in &solve_outcome.warnings {
            let message = if let Some(index) = warning.about_constraint.as_ref() {
                format!("{}; constraint index {}", warning.content, index)
            } else {
                format!("{}", warning.content)
            };
            exec_state.warn(CompilationIssue::err(range, message), annotations::WARN_SOLVER);
        }
        if solve_outcome.converged {
            exec_state.mod_local.artifacts.refactor_metadata.extend(
                sketch_block_state
                    .pending_legacy_angle_refactor_metadata
                    .iter()
                    .filter_map(|pending| {
                        finalize_legacy_angle_refactor_meta(pending, &solve_outcome.final_values)
                            .map(RefactorMetadata::LegacyAngle)
                    }),
            );
        }
        // Substitute solutions back into sketch variables.
        let sketch_engine_id = exec_state.next_uuid();
        let solution_ty = solver_numeric_type(exec_state);
        let mut solved_segments = Vec::with_capacity(sketch_block_state.needed_by_engine.len());
        for unsolved_segment in &sketch_block_state.needed_by_engine {
            solved_segments.push(substitute_sketch_var_in_segment(
                unsolved_segment.clone(),
                sketch_surface,
                sketch_engine_id,
                None,
                &solve_outcome,
                solver_numeric_type(exec_state),
                solve_analysis.as_ref(),
            )?);
        }
        // Store variable solutions so that the sketch refactoring API can
        // write them back to the source. When editing a sketch block, we
        // exit early so that the sketch block that we're editing is always
        // the last one. Therefore, we should overwrite any previous
        // solutions.
        exec_state.mod_local.artifacts.var_solutions =
            sketch_block_state.var_solutions(&solve_outcome, solution_ty, SourceRange::from(self))?;

        // Create scene objects after unknowns are solved.
        let scene_objects = create_segment_scene_objects(&solved_segments, range, exec_state)?;

        // Build the sketch and send everything to the engine.
        let sketch = create_segments_in_engine(
            sketch_surface,
            sketch_engine_id,
            &mut solved_segments,
            &sketch_block_state.segment_tags,
            ctx,
            exec_state,
            range,
        )
        .await?;

        // We now have enough information to fill in the path.
        if let Some(sketch_artifact_id) = sketch.as_ref().map(|s| s.artifact_id) {
            if let Some(Artifact::SketchBlock(sketch_block_artifact)) =
                exec_state.artifact_mut(sketch_block_artifact_id)
            {
                sketch_block_artifact.path_id = Some(sketch_artifact_id);
            } else {
                let message = "Sketch block artifact not found, so path couldn't be linked to it".to_owned();
                debug_assert!(false, "{message}");
                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
            }
        }

        // Substitute solutions back into sketch variables. This time, collect
        // all the variables in the sketch block. The set of variables may have
        // overlap with the objects sent to the engine, but it isn't necessarily
        // the same.
        let variables = substitute_sketch_vars(
            variables,
            sketch_surface,
            sketch_engine_id,
            sketch.as_ref(),
            &solve_outcome,
            solution_ty,
            solve_analysis.as_ref(),
        )?;

        let mut segment_object_ids = Vec::with_capacity(scene_objects.len());
        for scene_object in scene_objects {
            segment_object_ids.push(scene_object.id);
            // Fill in placeholder scene objects.
            exec_state.set_scene_object(scene_object);
        }
        // Update the sketch scene object with the segments.
        let Some(sketch_object) = exec_state.mod_local.artifacts.scene_object_by_id_mut(sketch_id) else {
            let message = format!("Sketch object not found after it was just created; id={:?}", sketch_id);
            debug_assert!(false, "{}", &message);
            return Err(internal_err(message, range));
        };
        let ObjectKind::Sketch(front_sketch) = &mut sketch_object.kind else {
            let message = format!(
                "Expected Sketch object after it was just created to be a sketch kind; id={:?}, actual={:?}",
                sketch_id, sketch_object
            );
            debug_assert!(
                false,
                "{}; scene_objects={:#?}",
                message, exec_state.mod_local.artifacts.scene_objects
            );
            return Err(internal_err(message, range));
        };
        front_sketch.segments.extend(segment_object_ids);
        // Update the sketch scene object with constraints.
        front_sketch
            .constraints
            .extend(std::mem::take(&mut sketch_block_state.sketch_constraints));

        // Close the sketch block operation group.
        exec_state.push_op(Operation::GroupEnd);

        // Warn if the sketch has conflicting constraints. Skip this when
        // freedom analysis didn't run (e.g., during dragging), because the
        // freedom values on points are stale defaults in that case.
        if exec_state.mod_local.freedom_analysis {
            let status = {
                let scene_objects = &exec_state.mod_local.artifacts.scene_objects;
                scene_objects
                    .get(sketch_id.0)
                    .and_then(|obj| sketch_constraint_status_for_sketch(scene_objects, obj))
            };
            if let Some(status) = status
                && status.status == ConstraintKind::OverConstrained
            {
                let description = if status.conflict_count == 1 {
                    "segment has"
                } else {
                    "segments have"
                };
                let message = format!(
                    "Sketch is over-constrained: {} {description} conflicting constraints.{}",
                    status.conflict_count,
                    signed_distance_conflict_hint(&solve_outcome),
                );
                exec_state.warn(
                    CompilationIssue::err(range, message),
                    annotations::WARN_OVER_CONSTRAINED_SKETCH,
                );
            }
        }

        let properties = self.sketch_properties(sketch, variables);
        let metadata = Metadata {
            source_range: SourceRange::from(self),
        };
        let return_value = KclValue::Object {
            value: properties,
            constrainable: Default::default(),
            object_kind: KclObjectKind::Default,
            meta: vec![metadata],
        };
        Ok(return_value)
    }

    /// Report a non-fatal error for each argument that isn't a valid sketch
    /// block parameter. Currently, the only valid parameter is `on`.
    fn check_for_unexpected_arguments(&self, args: &Args, exec_state: &mut ExecState) -> Result<(), KclError> {
        if !args.unlabeled.is_empty() {
            let message = "Sketch block doesn't support unlabeled arguments; argument shorthand should have already been desugared";
            debug_assert!(false, "{message}");
            return Err(KclError::new_internal(KclErrorDetails::new(
                message.to_owned(),
                vec![args.source_range],
            )));
        }
        for (label, arg) in &args.labeled {
            if label == SKETCH_BLOCK_PARAM_ON {
                continue;
            }
            exec_state.err(CompilationIssue::err(
                arg.source_range,
                unexpected_kw_arg_message(label, Some(SketchBlock::CALLEE_NAME)),
            ));
        }
        Ok(())
    }

    pub(super) async fn load_sketch2_into_current_scope(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
        source_range: SourceRange,
    ) -> Result<(), KclError> {
        let path = vec!["std".to_owned(), "solver".to_owned()];
        let resolved_path = ModulePath::from_std_import_path(&path)?;
        let module_id = ctx
            .open_module(&ImportPath::Std { path }, &[], &resolved_path, exec_state, source_range)
            .await?;
        let (env_ref, exports) = ctx.exec_module_for_items(module_id, exec_state, source_range).await?;

        for name in exports {
            let value = exec_state
                .stack()
                .memory
                .get_from_owned(&name, env_ref, source_range, 0)?;
            exec_state.mut_stack().add(name, value, source_range)?;
        }
        Ok(())
    }

    /// Augment the variables in the sketch block with properties that should be
    /// accessible on the returned sketch object. This includes metadata like
    /// the sketch so that the engine ID and surface can be accessed.
    pub(crate) fn sketch_properties(
        &self,
        sketch: Option<Sketch>,
        variables: HashMap<String, KclValue>,
    ) -> HashMap<String, KclValue> {
        let Some(sketch) = sketch else {
            // The sketch block did not produce a Sketch, so we cannot provide
            // it.
            return variables;
        };

        let mut properties = variables;

        let sketch_value = KclValue::Sketch {
            value: Box::new(sketch),
        };
        let mut meta_map = HashMap::with_capacity(1);
        meta_map.insert(SKETCH_OBJECT_META_SKETCH.to_owned(), sketch_value);
        let meta_value = KclValue::Object {
            value: meta_map,
            constrainable: false,
            object_kind: KclObjectKind::Default,
            meta: vec![Metadata {
                source_range: SourceRange::from(self),
            }],
        };

        properties.insert(SKETCH_OBJECT_META.to_owned(), meta_value);

        properties
    }
}

impl SketchBlock {
    pub(super) fn prep_mem(&self, parent: EnvironmentRef, exec_state: &mut ExecState) -> Result<(), KclError> {
        exec_state.mut_stack().push_new_env_for_call(parent)
    }
}

impl Node<SketchVar> {
    pub async fn get_result(&self, exec_state: &mut ExecState, _ctx: &ExecutorContext) -> Result<KclValue, KclError> {
        let Some(sketch_block_state) = &exec_state.mod_local.sketch_block else {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                "Cannot use a sketch variable outside of a sketch block".to_owned(),
                vec![SourceRange::from(self)],
            )));
        };
        let id = sketch_block_state.next_sketch_var_id();
        let sketch_var = if let Some(initial) = &self.initial {
            KclValue::from_sketch_var_literal(initial, id, self.node_path.clone(), exec_state)
        } else {
            let metadata = Metadata {
                source_range: SourceRange::from(self),
            };

            KclValue::SketchVar {
                value: Box::new(super::SketchVar {
                    id,
                    initial_value: 0.0,
                    ty: NumericType::default(),
                    node_path: self.node_path.clone(),
                    meta: vec![metadata],
                }),
            }
        };

        let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                "Cannot use a sketch variable outside of a sketch block".to_owned(),
                vec![SourceRange::from(self)],
            )));
        };
        sketch_block_state.sketch_vars.push(sketch_var.clone());

        Ok(sketch_var)
    }
}

pub(super) async fn apply_ascription(
    value: &KclValue,
    ty: &Node<Type>,
    exec_state: &mut ExecState,
    ctx: &ExecutorContext,
    source_range: SourceRange,
) -> Result<KclValue, KclError> {
    let ty = RuntimeType::from_parsed(ty.inner.clone(), exec_state, ctx, value.into(), false, false).await?;

    if matches!(&ty, &RuntimeType::Primitive(PrimitiveType::Number(..))) {
        exec_state.clear_units_warnings(&source_range);
    }

    value.coerce(&ty, CoercionMode::explicit(), exec_state).map_err(|e| {
        // A coercion that knows why it failed says so; the generic wording below
        // would replace that with a worse description of the same failure.
        if let Some(message) = e.message {
            return KclError::new_semantic(KclErrorDetails::new(message, vec![source_range]));
        }

        let suggestion = if ty == RuntimeType::length() {
            ", you might try coercing to a fully specified numeric type such as `mm`"
        } else if ty == RuntimeType::angle() {
            ", you might try coercing to a fully specified numeric type such as `deg`"
        } else {
            ""
        };
        let ty_str = if let Some(ty) = value.principal_type() {
            format!("(with type `{ty}`) ")
        } else {
            String::new()
        };
        KclError::new_semantic(KclErrorDetails::new(
            format!(
                "could not coerce {} {ty_str}to type `{ty}`{suggestion}",
                value.human_friendly_type()
            ),
            vec![source_range],
        ))
    })
}

impl BinaryPart {
    #[async_recursion]
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        match self {
            BinaryPart::Literal(literal) => Ok(KclValue::from_literal((**literal).clone(), exec_state).continue_()),
            BinaryPart::Name(name) => {
                let metadata = Metadata {
                    source_range: SourceRange::from(&**name),
                };
                ctx.resolve_name_for_eval(name, &metadata, exec_state)
                    .await
                    .map(KclValue::continue_)
            }
            BinaryPart::BinaryExpression(binary_expression) => binary_expression.get_result(exec_state, ctx).await,
            BinaryPart::CallExpressionKw(call_expression) => call_expression.execute(exec_state, ctx).await,
            BinaryPart::UnaryExpression(unary_expression) => unary_expression.get_result(exec_state, ctx).await,
            BinaryPart::MemberExpression(member_expression) => member_expression.get_result(exec_state, ctx).await,
            BinaryPart::ArrayExpression(e) => e.execute(exec_state, ctx).await,
            BinaryPart::ArrayRangeExpression(e) => e.execute(exec_state, ctx).await,
            BinaryPart::ObjectExpression(e) => e.execute(exec_state, ctx).await,
            BinaryPart::IfExpression(e) => e.get_result(exec_state, ctx).await,
            BinaryPart::AscribedExpression(e) => e.get_result(exec_state, ctx).await,
            BinaryPart::SketchVar(e) => e.get_result(exec_state, ctx).await.map(KclValue::continue_),
        }
    }
}

impl Node<Name> {
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValue, KclError> {
        // Await first so being_declared is read only on the error path,
        // instead of cloned before every lookup.
        let result = self.get_result_inner(exec_state, ctx).await;
        result.map_err(|e| var_in_own_ref_err(e, &exec_state.mod_local.being_declared))
    }

    async fn get_result_inner(&self, exec_state: &mut ExecState, ctx: &ExecutorContext) -> Result<KclValue, KclError> {
        if self.abs_path {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                ABSOLUTE_PATHS_NOT_SUPPORTED.to_owned(),
                self.as_source_ranges(),
            )));
        }

        if self.path.is_empty() {
            if let Ok(item_value) = exec_state.stack().get(&self.name.name, self.into()) {
                return Ok(item_value);
            }

            let mod_name = format!("{}{}", memory::MODULE_PREFIX, self.name.name);
            let not_defined = match exec_state.stack().get(&mod_name, self.into()) {
                Ok(module) => return Ok(module),
                Err(err) => err,
            };

            // No value and no module of this name exists. If a type does, report
            // that instead: "is not defined" would point away from the mistake.
            return Err(type_used_as_value(exec_state, &self.name).unwrap_or(not_defined));
        }

        let mut mem_spec: Option<(EnvironmentRef, Vec<String>)> = None;
        for (index, p) in self.path.iter().enumerate() {
            // Only the last segment can name an enum, because what follows an
            // enum is a variant rather than something to traverse into.
            let non_enum_type = match enum_named_by_segment(exec_state, p, mem_spec.as_ref()) {
                Some(EnumPathHead::Enum(def)) => {
                    if let Some(next) = self.path.get(index + 1) {
                        return Err(KclError::new_semantic(KclErrorDetails::new(
                            format!(
                                "`{}` is an enum, so only a variant name can follow it. There is nothing to reach through `{}::{}`.",
                                p.name, p.name, next.name
                            ),
                            p.as_source_ranges(),
                        )));
                    }

                    return enum_variant_value(def, &self.name, exec_state);
                }
                Some(EnumPathHead::NonEnumType) => true,
                None => false,
            };

            let value = match mem_spec {
                Some((env, exports)) => {
                    if !exports.contains(&p.name) {
                        if non_enum_type {
                            return Err(non_enum_type_in_path(p));
                        }
                        return Err(KclError::new_semantic(KclErrorDetails::new(
                            format!("Item {} not found in module's exported items", p.name),
                            p.as_source_ranges(),
                        )));
                    }

                    exec_state
                        .stack()
                        .memory
                        .get_from_owned(&p.name, env, p.as_source_range(), 0)?
                }
                None => match exec_state
                    .stack()
                    .get(&format!("{}{}", memory::MODULE_PREFIX, p.name), self.into())
                {
                    Ok(value) => value,
                    Err(_) if non_enum_type => return Err(non_enum_type_in_path(p)),
                    Err(err) => return Err(err),
                },
            };

            let module_id = match value {
                KclValue::Module { value, .. } => value,
                value => {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "Identifier in path must refer to a module, found {}",
                            value.human_friendly_type()
                        ),
                        p.as_source_ranges(),
                    )));
                }
            };

            mem_spec = Some(
                ctx.exec_module_for_items(module_id, exec_state, p.as_source_range())
                    .await?,
            );
        }

        let (env, exports) = mem_spec.unwrap();

        let item_exported = exports.contains(&self.name.name);
        let item_value = exec_state
            .stack()
            .memory
            .get_from_owned(&self.name.name, env, self.name.as_source_range(), 0);

        // Item is defined and exported.
        if item_exported && item_value.is_ok() {
            return item_value;
        }

        let mod_name = format!("{}{}", memory::MODULE_PREFIX, self.name.name);
        let mod_exported = exports.contains(&mod_name);
        let mod_value = exec_state
            .stack()
            .memory
            .get_from_owned(&mod_name, env, self.name.as_source_range(), 0);

        // Module is defined and exported.
        if mod_exported && mod_value.is_ok() {
            return mod_value;
        }

        // Neither item or module is defined.
        if item_value.is_err() && mod_value.is_err() {
            return item_value;
        }

        // Either item or module is defined, but not exported.
        debug_assert!((item_value.is_ok() && !item_exported) || (mod_value.is_ok() && !mod_exported));
        Err(KclError::new_semantic(KclErrorDetails::new(
            format!("Item {} not found in module's exported items", self.name.name),
            self.name.as_source_ranges(),
        )))
    }
}

fn mock_array_may_have_engine_dependent_cardinality(ty: &RuntimeType) -> bool {
    match ty {
        RuntimeType::Primitive(
            PrimitiveType::Sketch
            | PrimitiveType::Solid
            | PrimitiveType::Face
            | PrimitiveType::Edge
            | PrimitiveType::BoundedEdge
            | PrimitiveType::ImportedGeometry,
        ) => true,
        RuntimeType::Union(types) => types.iter().any(mock_array_may_have_engine_dependent_cardinality),
        _ => false,
    }
}

impl Node<MemberExpression> {
    async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        if exec_state.entry_point_version_is_v3_or_higher() {
            // KCL 3.0: evaluate in source order, the object before the
            // property.
            let object = control_continue!(self.eval_object(exec_state, ctx).await?);
            let property = match self.eval_property(exec_state, ctx).await {
                Ok(property) => property,
                // The property expression exited, e.g. by calling exit().
                // Propagate the exit so that it terminates the enclosing module.
                Err(EarlyReturn::Value(cf)) => return Ok(cf),
                Err(EarlyReturn::Error(err)) => return Err(err),
            };
            return self.apply_member(object, property, exec_state, ctx).await;
        }

        // Pre-KCL-3.0: the property is evaluated before the object. This is
        // backwards with respect to the source text, but it is preserved
        // because ids and engine commands are order-dependent.
        let property = match self.eval_property(exec_state, ctx).await {
            Ok(property) => property,
            // The property expression exited, e.g. by calling exit().
            // Propagate the exit so that it terminates the enclosing module.
            Err(EarlyReturn::Value(cf)) => return Ok(cf),
            Err(EarlyReturn::Error(err)) => return Err(err),
        };
        let object = control_continue!(self.eval_object(exec_state, ctx).await?);
        self.apply_member(object, property, exec_state, ctx).await
    }

    /// Evaluate the object half of the member expression. It gets its own
    /// source range so that diagnostics raised while evaluating it (module
    /// errors, missing-return warnings) point at the object instead of the
    /// whole member expression.
    async fn eval_object(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        let object_meta = Metadata {
            source_range: SourceRange::from(&self.object),
        };
        ctx.execute_expr(&self.object, exec_state, &object_meta, &[], StatementKind::Expression)
            .await
    }

    /// Evaluate the property half of the member expression: a computed index
    /// is executed, while `obj.name` just reads the identifier. Likewise
    /// gets its own source range.
    async fn eval_property(&self, exec_state: &mut ExecState, ctx: &ExecutorContext) -> Result<Property, EarlyReturn> {
        let property_meta = Metadata {
            source_range: SourceRange::from(&self.property),
        };
        Property::try_from(
            self.computed,
            self.property.clone(),
            exec_state,
            self.into(),
            ctx,
            &property_meta,
            &[],
            StatementKind::Expression,
        )
        .await
    }

    /// Apply property access or indexing to an already-evaluated object: the
    /// evaluation-free second half of member-expression execution, shared by
    /// both executors.
    pub(super) async fn apply_member(
        &self,
        object: KclValue,
        property: Property,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        // Result values of the member access itself carry the whole
        // expression's metadata.
        let meta = Metadata {
            source_range: SourceRange::from(self),
        };

        // Check the property and object match -- e.g. ints for arrays, strs for objects.
        match (object, property, self.computed) {
            (KclValue::Segment { value: segment }, Property::String(property), false) => match property.as_str() {
                "at" => match &segment.repr {
                    SegmentRepr::Unsolved { segment } => {
                        match &segment.kind {
                            UnsolvedSegmentKind::Point { position, .. } => {
                                // TODO: assert that types of all elements are the same.
                                Ok(KclValue::HomArray {
                                    value: vec![
                                        KclValue::from_unsolved_expr(position[0].clone(), segment.meta.clone()),
                                        KclValue::from_unsolved_expr(position[1].clone(), segment.meta.clone()),
                                    ],
                                    ty: RuntimeType::any(),
                                }
                                .continue_())
                            }
                            _ => Err(KclError::new_undefined_value(
                                KclErrorDetails::new(
                                    format!("Property '{property}' not found in segment"),
                                    vec![self.clone().into()],
                                ),
                                None,
                            )),
                        }
                    }
                    SegmentRepr::Solved { segment } => {
                        match &segment.kind {
                            SegmentKind::Point { position, .. } => {
                                // TODO: assert that types of all elements are the same.
                                Ok(KclValue::array_from_point2d(
                                    [position[0].n, position[1].n],
                                    position[0].ty,
                                    segment.meta.clone(),
                                )
                                .continue_())
                            }
                            _ => Err(KclError::new_undefined_value(
                                KclErrorDetails::new(
                                    format!("Property '{property}' not found in segment"),
                                    vec![self.clone().into()],
                                ),
                                None,
                            )),
                        }
                    }
                },
                "start" => match &segment.repr {
                    SegmentRepr::Unsolved { segment } => match &segment.kind {
                        UnsolvedSegmentKind::Point { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in point segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                        UnsolvedSegmentKind::Line {
                            start,
                            ctor,
                            start_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *start_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: start.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.start.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        UnsolvedSegmentKind::Arc {
                            start,
                            ctor,
                            start_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *start_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: start.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.start.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        UnsolvedSegmentKind::Circle {
                            start,
                            ctor,
                            start_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *start_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: start.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.start.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        UnsolvedSegmentKind::ControlPointSpline { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                    SegmentRepr::Solved { segment } => match &segment.kind {
                        SegmentKind::Point { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in point segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                        SegmentKind::Line {
                            start,
                            ctor,
                            start_object_id,
                            start_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *start_object_id,
                                        kind: SegmentKind::Point {
                                            position: start.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.start.clone(),
                                            }),
                                            freedom: *start_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        SegmentKind::Arc {
                            start,
                            ctor,
                            start_object_id,
                            start_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *start_object_id,
                                        kind: SegmentKind::Point {
                                            position: start.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.start.clone(),
                                            }),
                                            freedom: *start_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        SegmentKind::Circle {
                            start,
                            ctor,
                            start_object_id,
                            start_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *start_object_id,
                                        kind: SegmentKind::Point {
                                            position: start.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.start.clone(),
                                            }),
                                            freedom: *start_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        SegmentKind::ControlPointSpline { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                },
                "end" => match &segment.repr {
                    SegmentRepr::Unsolved { segment } => match &segment.kind {
                        UnsolvedSegmentKind::Point { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in point segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                        UnsolvedSegmentKind::Line {
                            end,
                            ctor,
                            end_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *end_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: end.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.end.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        UnsolvedSegmentKind::Arc {
                            end,
                            ctor,
                            end_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *end_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: end.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.end.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        UnsolvedSegmentKind::Circle { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.into()],
                            ),
                            None,
                        )),
                        UnsolvedSegmentKind::ControlPointSpline { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                    SegmentRepr::Solved { segment } => match &segment.kind {
                        SegmentKind::Point { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in point segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                        SegmentKind::Line {
                            end,
                            ctor,
                            end_object_id,
                            end_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *end_object_id,
                                        kind: SegmentKind::Point {
                                            position: end.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.end.clone(),
                                            }),
                                            freedom: *end_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        SegmentKind::Arc {
                            end,
                            ctor,
                            end_object_id,
                            end_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *end_object_id,
                                        kind: SegmentKind::Point {
                                            position: end.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.end.clone(),
                                            }),
                                            freedom: *end_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        SegmentKind::Circle { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.into()],
                            ),
                            None,
                        )),
                        SegmentKind::ControlPointSpline { .. } => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                },
                "center" => match &segment.repr {
                    SegmentRepr::Unsolved { segment } => match &segment.kind {
                        UnsolvedSegmentKind::Arc {
                            center,
                            ctor,
                            center_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *center_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: center.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.center.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        UnsolvedSegmentKind::Circle {
                            center,
                            ctor,
                            center_object_id,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Unsolved {
                                    segment: Box::new(UnsolvedSegment {
                                        id: segment.id,
                                        object_id: *center_object_id,
                                        kind: UnsolvedSegmentKind::Point {
                                            position: center.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.center.clone(),
                                            }),
                                        },
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        _ => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                    SegmentRepr::Solved { segment } => match &segment.kind {
                        SegmentKind::Arc {
                            center,
                            ctor,
                            center_object_id,
                            center_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *center_object_id,
                                        kind: SegmentKind::Point {
                                            position: center.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.center.clone(),
                                            }),
                                            freedom: *center_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        SegmentKind::Circle {
                            center,
                            ctor,
                            center_object_id,
                            center_freedom,
                            ..
                        } => Ok(KclValue::Segment {
                            value: Box::new(AbstractSegment {
                                repr: SegmentRepr::Solved {
                                    segment: Box::new(Segment {
                                        id: segment.id,
                                        object_id: *center_object_id,
                                        kind: SegmentKind::Point {
                                            position: center.clone(),
                                            ctor: Box::new(PointCtor {
                                                position: ctor.center.clone(),
                                            }),
                                            freedom: *center_freedom,
                                        },
                                        surface: segment.surface.clone(),
                                        sketch_id: segment.sketch_id,
                                        sketch: segment.sketch.clone(),
                                        tag: segment.tag.clone(),
                                        node_path: segment.node_path.clone(),
                                        meta: segment.meta.clone(),
                                    }),
                                },
                                meta: segment.meta.clone(),
                            }),
                        }
                        .continue_()),
                        _ => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                },
                "controls" => match &segment.repr {
                    SegmentRepr::Unsolved { segment } => match &segment.kind {
                        UnsolvedSegmentKind::ControlPointSpline {
                            controls,
                            ctor,
                            control_object_ids,
                            ..
                        } => Ok(KclValue::HomArray {
                            value: controls
                                .iter()
                                .zip(control_object_ids.iter())
                                .zip(ctor.points.iter())
                                .map(|((position, object_id), ctor_point)| KclValue::Segment {
                                    value: Box::new(AbstractSegment {
                                        repr: SegmentRepr::Unsolved {
                                            segment: Box::new(UnsolvedSegment {
                                                id: segment.id,
                                                object_id: *object_id,
                                                kind: UnsolvedSegmentKind::Point {
                                                    position: position.clone(),
                                                    ctor: Box::new(PointCtor {
                                                        position: ctor_point.clone(),
                                                    }),
                                                },
                                                tag: segment.tag.clone(),
                                                node_path: segment.node_path.clone(),
                                                meta: segment.meta.clone(),
                                            }),
                                        },
                                        meta: segment.meta.clone(),
                                    }),
                                })
                                .collect(),
                            ty: RuntimeType::segment(),
                        }
                        .continue_()),
                        _ => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                    SegmentRepr::Solved { segment } => match &segment.kind {
                        SegmentKind::ControlPointSpline {
                            controls,
                            ctor,
                            control_object_ids,
                            control_freedoms,
                            ..
                        } => Ok(KclValue::HomArray {
                            value: controls
                                .iter()
                                .zip(control_object_ids.iter())
                                .zip(control_freedoms.iter())
                                .zip(ctor.points.iter())
                                .map(|(((position, object_id), freedom), ctor_point)| KclValue::Segment {
                                    value: Box::new(AbstractSegment {
                                        repr: SegmentRepr::Solved {
                                            segment: Box::new(Segment {
                                                id: segment.id,
                                                object_id: *object_id,
                                                kind: SegmentKind::Point {
                                                    position: position.clone(),
                                                    ctor: Box::new(PointCtor {
                                                        position: ctor_point.clone(),
                                                    }),
                                                    freedom: *freedom,
                                                },
                                                surface: segment.surface.clone(),
                                                sketch_id: segment.sketch_id,
                                                sketch: segment.sketch.clone(),
                                                tag: segment.tag.clone(),
                                                node_path: segment.node_path.clone(),
                                                meta: segment.meta.clone(),
                                            }),
                                        },
                                        meta: segment.meta.clone(),
                                    }),
                                })
                                .collect(),
                            ty: RuntimeType::segment(),
                        }
                        .continue_()),
                        _ => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                },
                "edges" => match &segment.repr {
                    SegmentRepr::Unsolved { segment } => match &segment.kind {
                        UnsolvedSegmentKind::ControlPointSpline {
                            controls,
                            ctor,
                            control_object_ids,
                            control_polygon_edge_object_ids,
                            construction,
                            ..
                        } => Ok(KclValue::HomArray {
                            value: control_polygon_edge_object_ids
                                .iter()
                                .enumerate()
                                .map(|(index, object_id)| KclValue::Segment {
                                    value: Box::new(AbstractSegment {
                                        repr: SegmentRepr::Unsolved {
                                            segment: Box::new(UnsolvedSegment {
                                                id: segment.id,
                                                object_id: *object_id,
                                                kind: UnsolvedSegmentKind::Line {
                                                    start: controls[index].clone(),
                                                    end: controls[index + 1].clone(),
                                                    ctor: Box::new(LineCtor {
                                                        start: ctor.points[index].clone(),
                                                        end: ctor.points[index + 1].clone(),
                                                        construction: Some(*construction),
                                                    }),
                                                    start_object_id: control_object_ids[index],
                                                    end_object_id: control_object_ids[index + 1],
                                                    construction: *construction,
                                                },
                                                tag: segment.tag.clone(),
                                                node_path: segment.node_path.clone(),
                                                meta: segment.meta.clone(),
                                            }),
                                        },
                                        meta: segment.meta.clone(),
                                    }),
                                })
                                .collect(),
                            ty: RuntimeType::segment(),
                        }
                        .continue_()),
                        _ => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                    SegmentRepr::Solved { segment } => match &segment.kind {
                        SegmentKind::ControlPointSpline {
                            controls,
                            ctor,
                            control_object_ids,
                            control_polygon_edge_object_ids,
                            control_freedoms,
                            construction,
                            ..
                        } => Ok(KclValue::HomArray {
                            value: control_polygon_edge_object_ids
                                .iter()
                                .enumerate()
                                .map(|(index, object_id)| KclValue::Segment {
                                    value: Box::new(AbstractSegment {
                                        repr: SegmentRepr::Solved {
                                            segment: Box::new(Segment {
                                                id: segment.id,
                                                object_id: *object_id,
                                                kind: SegmentKind::Line {
                                                    start: controls[index].clone(),
                                                    end: controls[index + 1].clone(),
                                                    ctor: Box::new(LineCtor {
                                                        start: ctor.points[index].clone(),
                                                        end: ctor.points[index + 1].clone(),
                                                        construction: Some(*construction),
                                                    }),
                                                    start_object_id: control_object_ids[index],
                                                    end_object_id: control_object_ids[index + 1],
                                                    start_freedom: control_freedoms[index],
                                                    end_freedom: control_freedoms[index + 1],
                                                    construction: *construction,
                                                },
                                                surface: segment.surface.clone(),
                                                sketch_id: segment.sketch_id,
                                                sketch: segment.sketch.clone(),
                                                tag: segment.tag.clone(),
                                                node_path: segment.node_path.clone(),
                                                meta: segment.meta.clone(),
                                            }),
                                        },
                                        meta: segment.meta.clone(),
                                    }),
                                })
                                .collect(),
                            ty: RuntimeType::segment(),
                        }
                        .continue_()),
                        _ => Err(KclError::new_undefined_value(
                            KclErrorDetails::new(
                                format!("Property '{property}' not found in segment"),
                                vec![self.clone().into()],
                            ),
                            None,
                        )),
                    },
                },
                other => Err(KclError::new_undefined_value(
                    KclErrorDetails::new(
                        format!("Property '{other}' not found in segment"),
                        vec![self.clone().into()],
                    ),
                    None,
                )),
            },
            (KclValue::Plane { value: plane }, Property::String(property), false) => match property.as_str() {
                "zAxis" => {
                    let (p, u) = plane.info.z_axis.as_3_dims();
                    Ok(KclValue::array_from_point3d(p, NumericType::optional_length(u), vec![meta]).continue_())
                }
                "yAxis" => {
                    let (p, u) = plane.info.y_axis.as_3_dims();
                    Ok(KclValue::array_from_point3d(p, NumericType::optional_length(u), vec![meta]).continue_())
                }
                "xAxis" => {
                    let (p, u) = plane.info.x_axis.as_3_dims();
                    Ok(KclValue::array_from_point3d(p, NumericType::optional_length(u), vec![meta]).continue_())
                }
                "origin" => {
                    let (p, u) = plane.info.origin.as_3_dims();
                    Ok(KclValue::array_from_point3d(p, NumericType::optional_length(u), vec![meta]).continue_())
                }
                other => Err(KclError::new_undefined_value(
                    KclErrorDetails::new(
                        format!("Property '{other}' not found in plane"),
                        vec![self.clone().into()],
                    ),
                    None,
                )),
            },
            (
                KclValue::Object {
                    value: map,
                    object_kind,
                    ..
                },
                Property::String(property),
                false,
            ) => {
                if let Some(value) = map.get(&property) {
                    if object_kind
                        .deprecated_solid_tag_names()
                        .iter()
                        .any(|tag_name| tag_name == &property)
                    {
                        exec_state.warn(
                            CompilationIssue::err(
                                SourceRange::from(self),
                                format!(
                                    "Accessing solid-created face `{property}` through sketch tags is deprecated. Use the body's faces instead, e.g. `body.faces.{property}`."
                                ),
                            ),
                            annotations::WARN_DEPRECATED,
                        );
                    }
                    Ok(value.to_owned().continue_())
                } else {
                    Err(KclError::new_undefined_value(
                        KclErrorDetails::new(
                            format!("Property '{property}' not found in object"),
                            vec![self.clone().into()],
                        ),
                        None,
                    ))
                }
            }
            (KclValue::Object { .. }, Property::String(property), true) => {
                Err(KclError::new_semantic(KclErrorDetails::new(
                    format!("Cannot index object with string; use dot notation instead, e.g. `obj.{property}`"),
                    vec![self.clone().into()],
                )))
            }
            (KclValue::Object { value: map, .. }, p @ Property::UInt(i), _) => {
                if i == 0
                    && let Some(value) = map.get("x")
                {
                    return Ok(value.to_owned().continue_());
                }
                if i == 1
                    && let Some(value) = map.get("y")
                {
                    return Ok(value.to_owned().continue_());
                }
                if i == 2
                    && let Some(value) = map.get("z")
                {
                    return Ok(value.to_owned().continue_());
                }
                let t = p.type_name();
                let article = article_for(t);
                Err(KclError::new_semantic(KclErrorDetails::new(
                    format!("Only strings can be used as the property of an object, but you're using {article} {t}",),
                    vec![self.clone().into()],
                )))
            }
            (KclValue::HomArray { value: arr, ty }, Property::UInt(index), _) => {
                let value_of_arr = arr.get(index);
                // Out-of-bounds error.
                let oob_error = KclError::new_undefined_value(
                    KclErrorDetails::new(
                        format!("The array doesn't have any item at index {index}"),
                        vec![self.clone().into()],
                    ),
                    None,
                );
                if let Some(value) = value_of_arr {
                    // Indexing into the array was successful.
                    Ok(value.to_owned().continue_())
                } else if ctx.no_engine_commands().await
                    && !exec_state.is_sketch_mode_execution()
                    && mock_array_may_have_engine_dependent_cardinality(&ty)
                {
                    // In mock execution, we handle OOB errors
                    // by trying to get index 0 only for geometry-handle arrays. Those
                    // values may have come from the engine, so their actual length is
                    // not known during mock execution runtime. Frontend-only arrays
                    // have exact cardinality and must preserve their OOB errors.
                    //
                    // We don't do this in sketch mode execution since it's
                    // forbidden from contacting the engine, meaning array
                    // lengths are always accurate, and the OOB error is real.
                    let value = arr.first();
                    value.map(|value| value.to_owned().continue_()).ok_or(oob_error)
                } else {
                    Err(oob_error)
                }
            }
            // Singletons and single-element arrays should be interchangeable, but only indexing by 0 should work.
            // This is kind of a silly property, but it's possible it occurs in generic code or something.
            (obj, Property::UInt(0), _) => Ok(obj.continue_()),
            (KclValue::HomArray { .. }, p, _) => {
                let t = p.type_name();
                let article = article_for(t);
                Err(KclError::new_semantic(KclErrorDetails::new(
                    format!("Only integers >= 0 can be used as the index of an array, but you're using {article} {t}",),
                    vec![self.clone().into()],
                )))
            }
            (KclValue::Solid { value }, Property::String(prop), false) if prop == "sketch" => {
                let Some(sketch) = value.sketch() else {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        "This solid was created without a sketch, so `solid.sketch` is unavailable.".to_owned(),
                        vec![self.clone().into()],
                    )));
                };
                Ok(KclValue::Sketch {
                    value: Box::new(sketch.clone()),
                }
                .continue_())
            }
            (KclValue::Solid { value: solid }, Property::String(prop), false) if prop == "faces" => {
                Ok(KclValue::Object {
                    meta: vec![Metadata {
                        source_range: SourceRange::from(self.clone()),
                    }],
                    value: solid
                        .faces
                        .iter()
                        .map(|(k, tag)| (k.to_owned(), KclValue::TagIdentifier(Box::new(tag.to_owned()))))
                        .collect(),
                    constrainable: false,
                    object_kind: KclObjectKind::Default,
                }
                .continue_())
            }
            (geometry @ KclValue::Solid { .. }, Property::String(prop), false) if prop == "tags" => {
                // This is a common mistake.
                Err(KclError::new_semantic(KclErrorDetails::new(
                    format!(
                        "Property `{prop}` not found on {}. You can get a solid's faces through `exampleSolid.faces`, or its sketch tags through `exampleSolid.sketch.tags`.",
                        geometry.human_friendly_type()
                    ),
                    vec![self.clone().into()],
                )))
            }
            (KclValue::Sketch { value: sk }, Property::String(prop), false) if prop == "tags" => Ok(KclValue::Object {
                meta: vec![Metadata {
                    source_range: SourceRange::from(self.clone()),
                }],
                value: sk
                    .tags
                    .iter()
                    .map(|(k, tag)| (k.to_owned(), KclValue::TagIdentifier(Box::new(tag.to_owned()))))
                    .collect(),
                constrainable: false,
                object_kind: KclObjectKind::SketchTags {
                    deprecated_solid_tag_names: sk
                        .tags
                        .iter()
                        .filter(|(_, tag)| tag.is_body_created_tag())
                        .map(|(name, _)| name.to_owned())
                        .collect(),
                },
            }
            .continue_()),
            (geometry @ (KclValue::Sketch { .. } | KclValue::Solid { .. }), Property::String(property), false) => {
                Err(KclError::new_semantic(KclErrorDetails::new(
                    format!("Property `{property}` not found on {}", geometry.human_friendly_type()),
                    vec![self.clone().into()],
                )))
            }
            (being_indexed, _, false) => Err(KclError::new_semantic(KclErrorDetails::new(
                format!(
                    "Only objects can have members accessed with dot notation, but you're trying to access {}",
                    being_indexed.human_friendly_type()
                ),
                vec![self.clone().into()],
            ))),
            (being_indexed, _, true) => Err(KclError::new_semantic(KclErrorDetails::new(
                format!(
                    "Only arrays can be indexed, but you're trying to index {}",
                    being_indexed.human_friendly_type()
                ),
                vec![self.clone().into()],
            ))),
        }
    }
}

impl Node<BinaryExpression> {
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        enum State {
            EvaluateLeft(Node<BinaryExpression>),
            FromLeft {
                node: Node<BinaryExpression>,
            },
            EvaluateRight {
                node: Node<BinaryExpression>,
                left: KclValue,
            },
            FromRight {
                node: Node<BinaryExpression>,
                left: KclValue,
            },
        }

        let mut stack = vec![State::EvaluateLeft(self.clone())];
        let mut last_result: Option<KclValue> = None;

        while let Some(state) = stack.pop() {
            match state {
                State::EvaluateLeft(node) => {
                    let left_part = node.left.clone();
                    match left_part {
                        BinaryPart::BinaryExpression(child) => {
                            stack.push(State::FromLeft { node });
                            stack.push(State::EvaluateLeft(child.into_node()));
                        }
                        part => {
                            let left_value = part.get_result(exec_state, ctx).await?;
                            let left_value = control_continue!(left_value);
                            stack.push(State::EvaluateRight { node, left: left_value });
                        }
                    }
                }
                State::FromLeft { node } => {
                    let Some(left_value) = last_result.take() else {
                        return Err(Self::missing_result_error(&node));
                    };
                    stack.push(State::EvaluateRight { node, left: left_value });
                }
                State::EvaluateRight { node, left } => {
                    let right_part = node.right.clone();
                    match right_part {
                        BinaryPart::BinaryExpression(child) => {
                            stack.push(State::FromRight { node, left });
                            stack.push(State::EvaluateLeft(child.into_node()));
                        }
                        part => {
                            let right_value = part.get_result(exec_state, ctx).await?;
                            let right_value = control_continue!(right_value);
                            let result = node.apply_operator(exec_state, ctx, left, right_value).await?;
                            last_result = Some(result);
                        }
                    }
                }
                State::FromRight { node, left } => {
                    let Some(right_value) = last_result.take() else {
                        return Err(Self::missing_result_error(&node));
                    };
                    let result = node.apply_operator(exec_state, ctx, left, right_value).await?;
                    last_result = Some(result);
                }
            }
        }

        last_result
            .map(KclValue::continue_)
            .ok_or_else(|| Self::missing_result_error(self))
    }

    pub(super) async fn apply_operator(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
        left_value: KclValue,
        right_value: KclValue,
    ) -> Result<KclValue, KclError> {
        let mut meta = left_value.metadata();
        meta.extend(right_value.metadata());

        // First check if we are doing string concatenation.
        if self.operator == BinaryOperator::Add
            && let (KclValue::String { value: left, .. }, KclValue::String { value: right, .. }) =
                (&left_value, &right_value)
        {
            return Ok(KclValue::String {
                value: format!("{left}{right}"),
                meta,
            });
        }

        // Then check if we have solids.
        if self.operator == BinaryOperator::Add || self.operator == BinaryOperator::Or {
            if let (KclValue::Solid { value: left }, KclValue::Solid { value: right }) = (&left_value, &right_value) {
                let args = Args::new_no_args(
                    self.into(),
                    self.node_path.clone(),
                    ctx.clone(),
                    Some("union".to_owned()),
                );
                let result = crate::std::csg::inner_union(
                    vec![*left.clone(), *right.clone()],
                    Default::default(),
                    crate::std::csg::CsgAlgorithm::Latest,
                    exec_state,
                    args,
                )
                .await?;
                return Ok(result.into());
            }
        } else if self.operator == BinaryOperator::Sub {
            // Check if we have solids.
            if let (KclValue::Solid { value: left }, KclValue::Solid { value: right }) = (&left_value, &right_value) {
                let args = Args::new_no_args(
                    self.into(),
                    self.node_path.clone(),
                    ctx.clone(),
                    Some("subtract".to_owned()),
                );
                let result = crate::std::csg::inner_subtract(
                    vec![*left.clone()],
                    vec![*right.clone()],
                    Default::default(),
                    crate::std::csg::CsgAlgorithm::Latest,
                    exec_state,
                    args,
                )
                .await?;
                return Ok(result.into());
            }
        } else if self.operator == BinaryOperator::And
            && let (KclValue::Solid { value: left }, KclValue::Solid { value: right }) = (&left_value, &right_value)
        {
            // Check if we have solids.
            let args = Args::new_no_args(
                self.into(),
                self.node_path.clone(),
                ctx.clone(),
                Some("intersect".to_owned()),
            );
            let result = crate::std::csg::inner_intersect(
                vec![*left.clone(), *right.clone()],
                Default::default(),
                crate::std::csg::CsgAlgorithm::Latest,
                exec_state,
                args,
            )
            .await?;
            return Ok(result.into());
        }

        // Check if we are doing logical operations on booleans.
        if self.operator == BinaryOperator::Or || self.operator == BinaryOperator::And {
            let KclValue::Bool { value: left_value, .. } = left_value else {
                return Err(KclError::new_semantic(KclErrorDetails::new(
                    format!(
                        "Cannot apply logical operator to non-boolean value: {}",
                        left_value.human_friendly_type()
                    ),
                    vec![self.left.clone().into()],
                )));
            };
            let KclValue::Bool { value: right_value, .. } = right_value else {
                return Err(KclError::new_semantic(KclErrorDetails::new(
                    format!(
                        "Cannot apply logical operator to non-boolean value: {}",
                        right_value.human_friendly_type()
                    ),
                    vec![self.right.clone().into()],
                )));
            };
            let raw_value = match self.operator {
                BinaryOperator::Or => left_value || right_value,
                BinaryOperator::And => left_value && right_value,
                _ => unreachable!(),
            };
            return Ok(KclValue::Bool { value: raw_value, meta });
        }

        // Check if we're doing equivalence in sketch mode.
        if self.operator == BinaryOperator::Eq && exec_state.mod_local.sketch_block.is_some() {
            match (&left_value, &right_value) {
                // Same sketch variables.
                (KclValue::SketchVar { value: left_value, .. }, KclValue::SketchVar { value: right_value, .. })
                    if left_value.id == right_value.id =>
                {
                    return Ok(KclValue::none());
                }
                // Different sketch variables.
                (KclValue::SketchVar { value: var0 }, KclValue::SketchVar { value: var1, .. }) => {
                    let constraint = Constraint::ScalarEqual(
                        var0.id.to_constraint_id(self.as_source_range())?,
                        var1.id.to_constraint_id(self.as_source_range())?,
                    );
                    let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                        let message = "Being inside a sketch block should have already been checked above".to_owned();
                        debug_assert!(false, "{}", &message);
                        return Err(internal_err(message, self));
                    };
                    sketch_block_state.solver_constraints.push(constraint);
                    return Ok(KclValue::none());
                }
                // One sketch variable, one number.
                (KclValue::SketchVar { value: var, .. }, input_number @ KclValue::Number { .. })
                | (input_number @ KclValue::Number { .. }, KclValue::SketchVar { value: var, .. }) => {
                    let number_value = normalize_to_solver_distance_unit(
                        input_number,
                        input_number.into(),
                        exec_state,
                        "fixed constraint value",
                    )?;
                    let Some(n) = number_value.as_ty_f64() else {
                        let message = format!(
                            "Expected number after coercion, but found {}",
                            number_value.human_friendly_type()
                        );
                        debug_assert!(false, "{}", &message);
                        return Err(internal_err(message, self));
                    };
                    let constraint = Constraint::Fixed(var.id.to_constraint_id(self.as_source_range())?, n.n);
                    let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                        let message = "Being inside a sketch block should have already been checked above".to_owned();
                        debug_assert!(false, "{}", &message);
                        return Err(internal_err(message, self));
                    };
                    sketch_block_state.solver_constraints.push(constraint);
                    exec_state.warn_experimental("scalar fixed constraint", self.as_source_range());
                    return Ok(KclValue::none());
                }
                // One sketch constraint, one number.
                (KclValue::SketchConstraint { value: constraint }, input_number @ KclValue::Number { .. })
                | (input_number @ KclValue::Number { .. }, KclValue::SketchConstraint { value: constraint }) => {
                    let number_value = match constraint.kind {
                        // These constraint kinds expect the RHS to be an angle.
                        SketchConstraintKind::Angle { .. } => normalize_to_solver_angle_unit(
                            input_number,
                            input_number.into(),
                            exec_state,
                            "fixed constraint value",
                        )?,
                        // These constraint kinds expect the RHS to be a distance.
                        SketchConstraintKind::Distance { .. }
                        | SketchConstraintKind::PointLineDistance { .. }
                        | SketchConstraintKind::LineLineDistance { .. }
                        | SketchConstraintKind::PointCircularDistance { .. }
                        | SketchConstraintKind::LineCircularDistance { .. }
                        | SketchConstraintKind::CircularCircularDistance { .. }
                        | SketchConstraintKind::Radius { .. }
                        | SketchConstraintKind::Diameter { .. }
                        | SketchConstraintKind::HorizontalDistance { .. }
                        | SketchConstraintKind::VerticalDistance { .. } => normalize_to_solver_distance_unit(
                            input_number,
                            input_number.into(),
                            exec_state,
                            "fixed constraint value",
                        )?,
                    };
                    let Some(n) = number_value.as_ty_f64() else {
                        let message = format!(
                            "Expected number after coercion, but found {}",
                            number_value.human_friendly_type()
                        );
                        debug_assert!(false, "{}", &message);
                        return Err(internal_err(message, self));
                    };
                    // Recast the number side of == to get the source expression text.
                    let number_binary_part = if matches!(&left_value, KclValue::SketchConstraint { .. }) {
                        &self.right
                    } else {
                        &self.left
                    };
                    let source = {
                        use crate::unparser::ExprContext;
                        let mut buf = String::new();
                        number_binary_part.recast(&mut buf, &Default::default(), 0, ExprContext::Other);
                        crate::frontend::sketch::ConstraintSource {
                            expr: buf,
                            is_literal: matches!(number_binary_part, BinaryPart::Literal(_)),
                        }
                    };

                    match &constraint.kind {
                        SketchConstraintKind::Angle {
                            line0,
                            line1,
                            mode,
                            label_position,
                        } => {
                            let range = self.as_source_range();
                            let desired_angle = match n.ty {
                                NumericType::Known(crate::exec::UnitType::Angle(crate::exec::UnitAngle::Degrees))
                                | NumericType::Default {
                                    len: _,
                                    angle: UnitAngle::Degrees,
                                } => ezpz::datatypes::Angle::from_degrees(n.n),
                                NumericType::Known(crate::exec::UnitType::Angle(crate::exec::UnitAngle::Radians))
                                | NumericType::Default {
                                    len: _,
                                    angle: UnitAngle::Radians,
                                } => ezpz::datatypes::Angle::from_radians(n.n),
                                NumericType::Known(crate::exec::UnitType::Count)
                                | NumericType::Known(crate::exec::UnitType::GenericLength)
                                | NumericType::Known(crate::exec::UnitType::GenericAngle)
                                | NumericType::Known(crate::exec::UnitType::Length(_))
                                | NumericType::Unknown
                                | NumericType::Any => {
                                    let message = format!("Expected angle but found {:?}", n);
                                    debug_assert!(false, "{}", &message);
                                    return Err(internal_err(message, self));
                                }
                            };
                            let angle_lowering = match *mode {
                                AngleConstraintMode::LinesAtAngle => {
                                    AngleConstraintLowering::LinesAtAngle(Box::new(PendingLegacyAngleRefactorMeta {
                                        source_range: constraint
                                            .meta
                                            .first()
                                            .map(|meta| meta.source_range)
                                            .unwrap_or(range),
                                        lines: [line0.clone(), line1.clone()],
                                        desired_angle_radians: desired_angle.to_radians(),
                                    }))
                                }
                                AngleConstraintMode::PointsAtAngle { sector, inverse } => {
                                    let sketch_vars = exec_state
                                        .mod_local
                                        .sketch_block
                                        .as_ref()
                                        .ok_or_else(|| {
                                            internal_err(
                                                "Being inside a sketch block should have already been checked above",
                                                self,
                                            )
                                        })?
                                        .sketch_vars
                                        .clone();
                                    let initial_line0 = constrainable_line_initial_positions(
                                        &sketch_vars,
                                        line0,
                                        exec_state,
                                        range,
                                        "angle line0",
                                    )?;
                                    let initial_line1 = constrainable_line_initial_positions(
                                        &sketch_vars,
                                        line1,
                                        exec_state,
                                        range,
                                        "angle line1",
                                    )?;
                                    let Some(initial_vertex) = intersect_lines_2d(initial_line0, initial_line1) else {
                                        return Err(KclError::new_semantic(KclErrorDetails::new(
                                            "angleDimension(lines = ..., sector = ...) requires non-parallel lines"
                                                .to_owned(),
                                            vec![range],
                                        )));
                                    };
                                    let (line0_representative, line0_direction) =
                                        representative_angle_endpoint(line0, initial_line0, initial_vertex, range)?;
                                    let (line1_representative, line1_direction) =
                                        representative_angle_endpoint(line1, initial_line1, initial_vertex, range)?;
                                    let sector_rays = angle_sector_rays(sector, inverse);
                                    let angle_kind =
                                        ezpz::datatypes::AngleKind::Other(remap_angle_for_representative_rays(
                                            sector_rays,
                                            [line0_direction, line1_direction],
                                            desired_angle,
                                        ));
                                    AngleConstraintLowering::PointsAtAngle(PointsAtAngleLineData {
                                        initial_vertex,
                                        representative_points: [line0_representative, line1_representative],
                                        angle_kind,
                                    })
                                }
                            };
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };
                            match angle_lowering {
                                AngleConstraintLowering::LinesAtAngle(refactor_meta) => {
                                    sketch_block_state.solver_constraints.push(Constraint::LinesAtAngle(
                                        datum_line_from_constrainable(line0, range)?,
                                        datum_line_from_constrainable(line1, range)?,
                                        ezpz::datatypes::AngleKind::Other(desired_angle),
                                    ));
                                    sketch_block_state
                                        .pending_legacy_angle_refactor_metadata
                                        .push(*refactor_meta);
                                }
                                AngleConstraintLowering::PointsAtAngle(points_at_angle_data) => {
                                    push_points_at_angle_for_lines(
                                        sketch_block_state,
                                        sketch_var_ty,
                                        [line0, line1],
                                        points_at_angle_data,
                                        range,
                                    )?
                                }
                            }
                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Angle;
                            use crate::front::SourceRef;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let (sector, inverse) = match *mode {
                                AngleConstraintMode::LinesAtAngle => (None, None),
                                AngleConstraintMode::PointsAtAngle { sector, inverse } => {
                                    (Some(front_angle_sector(sector)), Some(inverse))
                                }
                            };
                            let sketch_constraint = crate::front::Constraint::Angle(Angle {
                                lines: vec![line0.object_id, line1.object_id],
                                angle: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert angle units numeric suffix:", range)
                                })?,
                                sector,
                                inverse,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::Distance { points, label_position } => {
                            let range = self.as_source_range();
                            let p0 = &points[0];
                            let p1 = &points[1];
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };
                            match (p0, p1) {
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(p0),
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(p1),
                                ) => {
                                    let solver_pt0 = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        p0.vars.x.to_constraint_id(range)?,
                                        p0.vars.y.to_constraint_id(range)?,
                                    );
                                    let solver_pt1 = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        p1.vars.x.to_constraint_id(range)?,
                                        p1.vars.y.to_constraint_id(range)?,
                                    );
                                    sketch_block_state
                                        .solver_constraints
                                        .push(Constraint::Distance(solver_pt0, solver_pt1, n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(point),
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                )
                                | (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(point),
                                ) => {
                                    let origin_x_id = sketch_block_state.next_sketch_var_id();
                                    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                        value: Box::new(crate::execution::SketchVar {
                                            id: origin_x_id,
                                            initial_value: 0.0,
                                            ty: sketch_var_ty,
                                            // Synthesized origin coord for distance(); not source-backed.
                                            node_path: None,
                                            meta: vec![],
                                        }),
                                    });
                                    let origin_y_id = sketch_block_state.next_sketch_var_id();
                                    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                        value: Box::new(crate::execution::SketchVar {
                                            id: origin_y_id,
                                            initial_value: 0.0,
                                            ty: sketch_var_ty,
                                            // Synthesized origin coord for distance(); not source-backed.
                                            node_path: None,
                                            meta: vec![],
                                        }),
                                    });
                                    let origin_x = origin_x_id.to_constraint_id(range)?;
                                    let origin_y = origin_y_id.to_constraint_id(range)?;
                                    sketch_block_state
                                        .solver_constraints
                                        .push(Constraint::Fixed(origin_x, 0.0));
                                    sketch_block_state
                                        .solver_constraints
                                        .push(Constraint::Fixed(origin_y, 0.0));
                                    let solver_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        point.vars.x.to_constraint_id(range)?,
                                        point.vars.y.to_constraint_id(range)?,
                                    );
                                    let origin_point = ezpz::datatypes::inputs::DatumPoint::new_xy(origin_x, origin_y);
                                    sketch_block_state.solver_constraints.push(Constraint::Distance(
                                        solver_point,
                                        origin_point,
                                        n.n,
                                    ));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                ) => {
                                    return Err(internal_err(
                                        "distance() cannot constrain ORIGIN against ORIGIN".to_owned(),
                                        range,
                                    ));
                                }
                            }
                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let sketch_constraint = crate::front::Constraint::Distance(Distance {
                                segments: vec![
                                    match p0 {
                                        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
                                            ConstraintSegment::from(point.object_id)
                                        }
                                        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
                                            ConstraintSegment::ORIGIN
                                        }
                                    },
                                    match p1 {
                                        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
                                            ConstraintSegment::from(point.object_id)
                                        }
                                        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
                                            ConstraintSegment::ORIGIN
                                        }
                                    },
                                ],
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::PointLineDistance {
                            point,
                            line,
                            input_object_ids,
                            label_position,
                        } => {
                            let range = self.as_source_range();
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let sketch_vars = exec_state
                                .mod_local
                                .sketch_block
                                .as_ref()
                                .ok_or_else(|| {
                                    internal_err(
                                        "Being inside a sketch block should have already been checked above",
                                        self,
                                    )
                                })?
                                .sketch_vars
                                .clone();
                            let support_initial =
                                projected_point_on_line_initial_position(&sketch_vars, point, line, exec_state, range)?;
                            let solver_line = datum_line_from_constrainable(line, range)?;

                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };

                            // Lower point-line distance by adding a hidden
                            // support point on the line, then constrain the
                            // selected point-to-support segment to be
                            // perpendicular and equal to the requested
                            // distance.
                            let solver_point = datum_point_from_constrainable_or_origin(
                                sketch_block_state,
                                sketch_var_ty,
                                point,
                                range,
                            )?;
                            let support_x_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_x_id,
                                    initial_value: support_initial[0],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_y_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_y_id,
                                    initial_value: support_initial[1],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                support_x_id.to_constraint_id(range)?,
                                support_y_id.to_constraint_id(range)?,
                            );
                            let support_line =
                                ezpz::datatypes::inputs::DatumLineSegment::new(solver_point, support_point);

                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::PointLineDistance(support_point, solver_line, 0.0));
                            sketch_block_state.solver_constraints.push(Constraint::LinesAtAngle(
                                support_line,
                                solver_line,
                                ezpz::datatypes::AngleKind::Perpendicular,
                            ));
                            sketch_block_state.solver_constraints.push(Constraint::Distance(
                                solver_point,
                                support_point,
                                n.n,
                            ));

                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let sketch_constraint = crate::front::Constraint::Distance(Distance {
                                segments: input_object_ids
                                    .iter()
                                    .copied()
                                    .map(|id| id.map_or(ConstraintSegment::ORIGIN, ConstraintSegment::from))
                                    .collect(),
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::LineLineDistance {
                            line0,
                            line1,
                            input_object_ids,
                            label_position,
                        } => {
                            let range = self.as_source_range();
                            let reference_point = crate::execution::ConstrainablePoint2d {
                                vars: line0.vars[0].clone(),
                                object_id: line0.object_id,
                            };
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let sketch_vars = exec_state
                                .mod_local
                                .sketch_block
                                .as_ref()
                                .ok_or_else(|| {
                                    internal_err(
                                        "Being inside a sketch block should have already been checked above",
                                        self,
                                    )
                                })?
                                .sketch_vars
                                .clone();
                            let support_initial = projected_point_on_line_initial_position(
                                &sketch_vars,
                                &crate::execution::ConstrainablePoint2dOrOrigin::Point(reference_point.clone()),
                                line1,
                                exec_state,
                                range,
                            )?;
                            let solver_point = datum_point_from_constrainable(&reference_point, range)?;
                            let solver_line0 = datum_line_from_constrainable(line0, range)?;
                            let solver_line1 = datum_line_from_constrainable(line1, range)?;

                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };

                            // Lower line-line distance to the point-line
                            // construction above by choosing one endpoint on
                            // line0 as the reference point, forcing the lines
                            // parallel, and measuring perpendicularly to
                            // line1.
                            let support_x_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_x_id,
                                    initial_value: support_initial[0],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_y_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_y_id,
                                    initial_value: support_initial[1],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                support_x_id.to_constraint_id(range)?,
                                support_y_id.to_constraint_id(range)?,
                            );
                            let support_line =
                                ezpz::datatypes::inputs::DatumLineSegment::new(solver_point, support_point);

                            sketch_block_state.solver_constraints.push(Constraint::LinesAtAngle(
                                solver_line0,
                                solver_line1,
                                ezpz::datatypes::AngleKind::Parallel,
                            ));
                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::PointLineDistance(support_point, solver_line1, 0.0));
                            sketch_block_state.solver_constraints.push(Constraint::LinesAtAngle(
                                support_line,
                                solver_line1,
                                ezpz::datatypes::AngleKind::Perpendicular,
                            ));
                            sketch_block_state.solver_constraints.push(Constraint::Distance(
                                solver_point,
                                support_point,
                                n.n,
                            ));

                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let sketch_constraint = crate::front::Constraint::Distance(Distance {
                                segments: input_object_ids.iter().copied().map(ConstraintSegment::from).collect(),
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::PointCircularDistance {
                            point,
                            center,
                            start,
                            end,
                            input_object_ids,
                            label_position,
                        } => {
                            let range = self.as_source_range();
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let sketch_vars = exec_state
                                .mod_local
                                .sketch_block
                                .as_ref()
                                .ok_or_else(|| {
                                    internal_err(
                                        "Being inside a sketch block should have already been checked above",
                                        self,
                                    )
                                })?
                                .sketch_vars
                                .clone();
                            let circular =
                                circular_distance_datums(&sketch_vars, center, start, end.as_ref(), exec_state, range)?;

                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };

                            // Lower point-circular distance to exterior
                            // circle tangency: a hidden circle centered on the
                            // point has radius equal to the requested distance
                            // and is tangent to the target arc/circle.
                            let target_point = datum_point_from_constrainable_or_origin(
                                sketch_block_state,
                                sketch_var_ty,
                                point,
                                range,
                            )?;
                            push_circular_distance_constraints(
                                sketch_block_state,
                                sketch_var_ty,
                                target_point,
                                circular,
                                n.n,
                                range,
                            )?;

                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let sketch_constraint = crate::front::Constraint::Distance(Distance {
                                segments: input_object_ids
                                    .iter()
                                    .copied()
                                    .map(|id| id.map_or(ConstraintSegment::ORIGIN, ConstraintSegment::from))
                                    .collect(),
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::LineCircularDistance {
                            line,
                            center,
                            start,
                            end,
                            input_object_ids,
                            label_position,
                        } => {
                            let range = self.as_source_range();
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let sketch_vars = exec_state
                                .mod_local
                                .sketch_block
                                .as_ref()
                                .ok_or_else(|| {
                                    internal_err(
                                        "Being inside a sketch block should have already been checked above",
                                        self,
                                    )
                                })?
                                .sketch_vars
                                .clone();
                            let support_initial = projected_point_on_line_initial_position(
                                &sketch_vars,
                                &crate::execution::ConstrainablePoint2dOrOrigin::Point(center.clone()),
                                line,
                                exec_state,
                                range,
                            )?;
                            let solver_line = datum_line_from_constrainable(line, range)?;
                            let circular =
                                circular_distance_datums(&sketch_vars, center, start, end.as_ref(), exec_state, range)?;

                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };

                            // Lower line-circular distance by first projecting
                            // the circular center onto the target line with a
                            // hidden support point. The circular distance is
                            // then the point-circular construction from that
                            // support point.
                            let support_x_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_x_id,
                                    initial_value: support_initial[0],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_y_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_y_id,
                                    initial_value: support_initial[1],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                support_x_id.to_constraint_id(range)?,
                                support_y_id.to_constraint_id(range)?,
                            );
                            let support_line =
                                ezpz::datatypes::inputs::DatumLineSegment::new(circular.center, support_point);

                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::PointLineDistance(support_point, solver_line, 0.0));
                            sketch_block_state.solver_constraints.push(Constraint::LinesAtAngle(
                                support_line,
                                solver_line,
                                ezpz::datatypes::AngleKind::Perpendicular,
                            ));
                            push_circular_distance_constraints(
                                sketch_block_state,
                                sketch_var_ty,
                                support_point,
                                circular,
                                n.n,
                                range,
                            )?;

                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let sketch_constraint = crate::front::Constraint::Distance(Distance {
                                segments: input_object_ids.iter().copied().map(ConstraintSegment::from).collect(),
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::CircularCircularDistance {
                            center0,
                            start0,
                            end0,
                            center1,
                            start1,
                            end1,
                            input_object_ids,
                            label_position,
                        } => {
                            let range = self.as_source_range();
                            let sketch_var_ty = solver_numeric_type(exec_state);
                            let sketch_vars = exec_state
                                .mod_local
                                .sketch_block
                                .as_ref()
                                .ok_or_else(|| {
                                    internal_err(
                                        "Being inside a sketch block should have already been checked above",
                                        self,
                                    )
                                })?
                                .sketch_vars
                                .clone();
                            let circular0 = circular_distance_datums(
                                &sketch_vars,
                                center0,
                                start0,
                                end0.as_ref(),
                                exec_state,
                                range,
                            )?;
                            let circular1 = circular_distance_datums(
                                &sketch_vars,
                                center1,
                                start1,
                                end1.as_ref(),
                                exec_state,
                                range,
                            )?;
                            let support_initial = circular_circular_support_initial_position(
                                &sketch_vars,
                                center0,
                                center1,
                                circular0.radius_initial_value,
                                n.n,
                                exec_state,
                                range,
                            )?;

                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };

                            // Lower circular-circular distance with a hidden
                            // spacer circle of radius d/2. Constraining its
                            // center onto the line between target centers and
                            // making it exterior-tangent to both targets gives
                            // center distance r0 + d + r1.
                            let circular_target0 =
                                push_circular_radius_constraints(sketch_block_state, sketch_var_ty, circular0, range)?;
                            let circular_target1 =
                                push_circular_radius_constraints(sketch_block_state, sketch_var_ty, circular1, range)?;

                            let support_x_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_x_id,
                                    initial_value: support_initial[0],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_y_id = sketch_block_state.next_sketch_var_id();
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_y_id,
                                    initial_value: support_initial[1],
                                    ty: sketch_var_ty,
                                    // Synthesized support point coord for distance lowering; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                support_x_id.to_constraint_id(range)?,
                                support_y_id.to_constraint_id(range)?,
                            );

                            let support_radius_id = sketch_block_state.next_sketch_var_id();
                            let support_radius_value = n.n / 2.0;
                            sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                value: Box::new(crate::execution::SketchVar {
                                    id: support_radius_id,
                                    initial_value: support_radius_value,
                                    ty: sketch_var_ty,
                                    // Synthesized hidden support radius for circular-circular distance; not source-backed.
                                    node_path: None,
                                    meta: vec![],
                                }),
                            });
                            let support_radius =
                                ezpz::datatypes::inputs::DatumDistance::new(support_radius_id.to_constraint_id(range)?);
                            let support_circle = ezpz::datatypes::inputs::DatumCircle {
                                center: support_point,
                                radius: support_radius,
                            };
                            let center_line = ezpz::datatypes::inputs::DatumLineSegment::new(
                                circular_target0.center,
                                circular_target1.center,
                            );

                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::Fixed(support_radius.id, support_radius_value));
                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::PointLineDistance(support_point, center_line, 0.0));
                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::CircleTangentToCircle(
                                    circular_target0,
                                    support_circle,
                                    ezpz::CircleSide::Exterior,
                                ));
                            sketch_block_state
                                .solver_constraints
                                .push(Constraint::CircleTangentToCircle(
                                    support_circle,
                                    circular_target1,
                                    ezpz::CircleSide::Exterior,
                                ));

                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let sketch_constraint = crate::front::Constraint::Distance(Distance {
                                segments: input_object_ids.iter().copied().map(ConstraintSegment::from).collect(),
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&sketch_constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint {
                                        constraint: sketch_constraint,
                                    },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::Radius { .. } | SketchConstraintKind::Diameter { .. } => {
                            #[derive(Clone, Copy)]
                            enum CircularSegmentConstraintTarget {
                                Arc {
                                    object_id: ObjectId,
                                    end: [crate::execution::SketchVarId; 2],
                                    direction: ArcDirection,
                                },
                                Circle {
                                    object_id: ObjectId,
                                },
                            }

                            fn sketch_var_initial_value(
                                sketch_vars: &[KclValue],
                                id: crate::execution::SketchVarId,
                                exec_state: &mut ExecState,
                                range: SourceRange,
                            ) -> Result<f64, KclError> {
                                sketch_vars
                                    .get(id.0)
                                    .and_then(KclValue::as_sketch_var)
                                    .map(|sketch_var| {
                                        sketch_var
                                            .initial_value_to_solver_units(
                                                exec_state,
                                                range,
                                                "circle radius initial value",
                                            )
                                            .map(|value| value.n)
                                    })
                                    .transpose()?
                                    .ok_or_else(|| {
                                        internal_err(
                                            format!("Missing sketch variable initial value for id {}", id.0),
                                            range,
                                        )
                                    })
                            }

                            let (points, label_position) = match &constraint.kind {
                                SketchConstraintKind::Radius { points, label_position } => {
                                    (points, label_position.clone())
                                }
                                SketchConstraintKind::Diameter { points, label_position } => {
                                    (points, label_position.clone())
                                }
                                _ => unreachable!(),
                            };
                            let range = self.as_source_range();
                            let center = &points[0];
                            let start = &points[1];
                            let Some(sketch_block_state) = &exec_state.mod_local.sketch_block else {
                                return Err(internal_err(
                                    "Being inside a sketch block should have already been checked above",
                                    self,
                                ));
                            };
                            let (constraint_name, is_diameter) = match &constraint.kind {
                                SketchConstraintKind::Radius { .. } => ("radius", false),
                                SketchConstraintKind::Diameter { .. } => ("diameter", true),
                                _ => unreachable!(),
                            };
                            let sketch_vars = sketch_block_state.sketch_vars.clone();
                            let target_segment = sketch_block_state
                                .needed_by_engine
                                .iter()
                                .find_map(|seg| match &seg.kind {
                                    UnsolvedSegmentKind::Arc {
                                        center_object_id,
                                        start_object_id,
                                        end,
                                        direction,
                                        ..
                                    } if *center_object_id == center.object_id
                                        && *start_object_id == start.object_id =>
                                    {
                                        let (end_x_var, end_y_var) = match (&end[0], &end[1]) {
                                            (UnsolvedExpr::Unknown(end_x), UnsolvedExpr::Unknown(end_y)) => {
                                                (*end_x, *end_y)
                                            }
                                            _ => return None,
                                        };
                                        Some(CircularSegmentConstraintTarget::Arc {
                                            object_id: seg.object_id,
                                            end: [end_x_var, end_y_var],
                                            direction: *direction,
                                        })
                                    }
                                    UnsolvedSegmentKind::Circle {
                                        center_object_id,
                                        start_object_id,
                                        ..
                                    } if *center_object_id == center.object_id
                                        && *start_object_id == start.object_id =>
                                    {
                                        Some(CircularSegmentConstraintTarget::Circle {
                                            object_id: seg.object_id,
                                        })
                                    }
                                    _ => None,
                                })
                                .ok_or_else(|| {
                                    internal_err(
                                        format!("Could not find circular segment for {} constraint", constraint_name),
                                        range,
                                    )
                                })?;
                            let radius_value = if is_diameter { n.n / 2.0 } else { n.n };
                            let center_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                center.vars.x.to_constraint_id(range)?,
                                center.vars.y.to_constraint_id(range)?,
                            );
                            let start_point = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                start.vars.x.to_constraint_id(range)?,
                                start.vars.y.to_constraint_id(range)?,
                            );
                            let solver_constraint = match target_segment {
                                CircularSegmentConstraintTarget::Arc { end, direction, .. } => {
                                    let solver_arc = SolverArc::new(
                                        [center.vars.x, center.vars.y],
                                        [start.vars.x, start.vars.y],
                                        end,
                                        direction,
                                        range,
                                    )?;
                                    solver_arc.radius_constraint(radius_value)
                                }
                                CircularSegmentConstraintTarget::Circle { .. } => {
                                    let sketch_var_ty = solver_numeric_type(exec_state);
                                    let start_x =
                                        sketch_var_initial_value(&sketch_vars, start.vars.x, exec_state, range)?;
                                    let start_y =
                                        sketch_var_initial_value(&sketch_vars, start.vars.y, exec_state, range)?;
                                    let center_x =
                                        sketch_var_initial_value(&sketch_vars, center.vars.x, exec_state, range)?;
                                    let center_y =
                                        sketch_var_initial_value(&sketch_vars, center.vars.y, exec_state, range)?;

                                    // Get the hypotenuse between the two points, the radius
                                    let radius_initial_value = libm::hypot(start_x - center_x, start_y - center_y);

                                    let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                        let message =
                                            "Being inside a sketch block should have already been checked above"
                                                .to_owned();
                                        debug_assert!(false, "{}", &message);
                                        return Err(internal_err(message, self));
                                    };
                                    let radius_id = sketch_block_state.next_sketch_var_id();
                                    sketch_block_state.sketch_vars.push(KclValue::SketchVar {
                                        value: Box::new(crate::execution::SketchVar {
                                            id: radius_id,
                                            initial_value: radius_initial_value,
                                            ty: sketch_var_ty,
                                            // Synthesized hidden radius for circle constraint; not source-backed.
                                            node_path: None,
                                            meta: vec![],
                                        }),
                                    });
                                    let radius =
                                        ezpz::datatypes::inputs::DatumDistance::new(radius_id.to_constraint_id(range)?);
                                    let solver_circle = ezpz::datatypes::inputs::DatumCircle {
                                        center: center_point,
                                        radius,
                                    };
                                    sketch_block_state.solver_constraints.push(Constraint::DistanceVar(
                                        start_point,
                                        center_point,
                                        radius,
                                    ));
                                    Constraint::CircleRadius(solver_circle, radius_value)
                                }
                            };

                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };
                            sketch_block_state.solver_constraints.push(solver_constraint);
                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::SourceRef;
                            let segment_object_id = match target_segment {
                                CircularSegmentConstraintTarget::Arc { object_id, .. }
                                | CircularSegmentConstraintTarget::Circle { object_id } => object_id,
                            };

                            let constraint = if is_diameter {
                                use crate::frontend::sketch::Diameter;
                                crate::front::Constraint::Diameter(Diameter {
                                    arc: segment_object_id,
                                    diameter: n.try_into().map_err(|_| {
                                        internal_err("Failed to convert diameter units numeric suffix:", range)
                                    })?,
                                    label_position,
                                    source,
                                })
                            } else {
                                use crate::frontend::sketch::Radius;
                                crate::front::Constraint::Radius(Radius {
                                    arc: segment_object_id,
                                    radius: n.try_into().map_err(|_| {
                                        internal_err("Failed to convert radius units numeric suffix:", range)
                                    })?,
                                    label_position,
                                    source,
                                })
                            };
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint { constraint },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::HorizontalDistance { points, label_position } => {
                            let range = self.as_source_range();
                            let p0 = &points[0];
                            let p1 = &points[1];
                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };
                            match (p0, p1) {
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(p0),
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(p1),
                                ) => {
                                    let solver_pt0 = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        p0.vars.x.to_constraint_id(range)?,
                                        p0.vars.y.to_constraint_id(range)?,
                                    );
                                    let solver_pt1 = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        p1.vars.x.to_constraint_id(range)?,
                                        p1.vars.y.to_constraint_id(range)?,
                                    );
                                    sketch_block_state
                                        .solver_constraints
                                        .push(ezpz::Constraint::HorizontalDistance(solver_pt1, solver_pt0, n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(point),
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                ) => {
                                    // horizontalDistance([point, ORIGIN]) == n means 0 - point.x = n, so point.x = -n.
                                    sketch_block_state
                                        .solver_constraints
                                        .push(ezpz::Constraint::Fixed(point.vars.x.to_constraint_id(range)?, -n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(point),
                                ) => {
                                    // horizontalDistance([ORIGIN, point]) == n means point.x - 0 = n, so point.x = n.
                                    sketch_block_state
                                        .solver_constraints
                                        .push(ezpz::Constraint::Fixed(point.vars.x.to_constraint_id(range)?, n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                ) => {
                                    return Err(internal_err(
                                        "horizontalDistance() cannot constrain ORIGIN against ORIGIN".to_owned(),
                                        range,
                                    ));
                                }
                            }
                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let constraint = crate::front::Constraint::HorizontalDistance(Distance {
                                segments: vec![
                                    match p0 {
                                        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
                                            ConstraintSegment::from(point.object_id)
                                        }
                                        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
                                            ConstraintSegment::ORIGIN
                                        }
                                    },
                                    match p1 {
                                        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
                                            ConstraintSegment::from(point.object_id)
                                        }
                                        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
                                            ConstraintSegment::ORIGIN
                                        }
                                    },
                                ],
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint { constraint },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                        SketchConstraintKind::VerticalDistance { points, label_position } => {
                            let range = self.as_source_range();
                            let p0 = &points[0];
                            let p1 = &points[1];
                            let constraint_id = exec_state.next_object_id();
                            let Some(sketch_block_state) = &mut exec_state.mod_local.sketch_block else {
                                let message =
                                    "Being inside a sketch block should have already been checked above".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(internal_err(message, self));
                            };
                            match (p0, p1) {
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(p0),
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(p1),
                                ) => {
                                    let solver_pt0 = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        p0.vars.x.to_constraint_id(range)?,
                                        p0.vars.y.to_constraint_id(range)?,
                                    );
                                    let solver_pt1 = ezpz::datatypes::inputs::DatumPoint::new_xy(
                                        p1.vars.x.to_constraint_id(range)?,
                                        p1.vars.y.to_constraint_id(range)?,
                                    );
                                    sketch_block_state
                                        .solver_constraints
                                        .push(ezpz::Constraint::VerticalDistance(solver_pt1, solver_pt0, n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(point),
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                ) => {
                                    sketch_block_state
                                        .solver_constraints
                                        .push(ezpz::Constraint::Fixed(point.vars.y.to_constraint_id(range)?, -n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                    crate::execution::ConstrainablePoint2dOrOrigin::Point(point),
                                ) => {
                                    sketch_block_state
                                        .solver_constraints
                                        .push(ezpz::Constraint::Fixed(point.vars.y.to_constraint_id(range)?, n.n));
                                }
                                (
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                    crate::execution::ConstrainablePoint2dOrOrigin::Origin,
                                ) => {
                                    return Err(internal_err(
                                        "verticalDistance() cannot constrain ORIGIN against ORIGIN".to_owned(),
                                        range,
                                    ));
                                }
                            }
                            use crate::execution::Artifact;
                            use crate::execution::CodeRef;
                            use crate::execution::SketchBlockConstraint;
                            use crate::front::Distance;
                            use crate::front::SourceRef;
                            use crate::frontend::sketch::ConstraintSegment;

                            let constraint = crate::front::Constraint::VerticalDistance(Distance {
                                segments: vec![
                                    match p0 {
                                        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
                                            ConstraintSegment::from(point.object_id)
                                        }
                                        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
                                            ConstraintSegment::ORIGIN
                                        }
                                    },
                                    match p1 {
                                        crate::execution::ConstrainablePoint2dOrOrigin::Point(point) => {
                                            ConstraintSegment::from(point.object_id)
                                        }
                                        crate::execution::ConstrainablePoint2dOrOrigin::Origin => {
                                            ConstraintSegment::ORIGIN
                                        }
                                    },
                                ],
                                distance: n.try_into().map_err(|_| {
                                    internal_err("Failed to convert distance units numeric suffix:", range)
                                })?,
                                label_position: label_position.clone(),
                                source,
                            });
                            sketch_block_state.sketch_constraints.push(constraint_id);
                            let Some(sketch_id) = sketch_block_state.sketch_id else {
                                let message = "Sketch id missing for constraint artifact".to_owned();
                                debug_assert!(false, "{}", &message);
                                return Err(KclError::new_internal(KclErrorDetails::new(message, vec![range])));
                            };
                            let artifact_id = exec_state.next_artifact_id();
                            exec_state.add_artifact(Artifact::SketchBlockConstraint(SketchBlockConstraint {
                                id: artifact_id,
                                sketch_id,
                                constraint_id,
                                constraint_type: super::artifact::sketch_block_constraint_type(&constraint),
                                code_ref: CodeRef::placeholder(range),
                            }));
                            exec_state.add_scene_object(
                                Object {
                                    id: constraint_id,
                                    kind: ObjectKind::Constraint { constraint },
                                    label: Default::default(),
                                    comments: Default::default(),
                                    artifact_id,
                                    source: SourceRef::new(range, self.node_path.clone()),
                                },
                                range,
                            );
                        }
                    }
                    return Ok(KclValue::none());
                }
                _ => {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "Cannot create an equivalence constraint between values of these types: {} and {}",
                            left_value.human_friendly_type(),
                            right_value.human_friendly_type()
                        ),
                        vec![self.into()],
                    )));
                }
            }
        }

        // Inside sketch blocks, `==` is reserved for equivalence constraints
        // and has already been handled above.
        if matches!(self.operator, BinaryOperator::Eq | BinaryOperator::Neq)
            && let (KclValue::String { value: left, .. }, KclValue::String { value: right, .. }) =
                (&left_value, &right_value)
        {
            let is_equal = left == right;
            let value = if self.operator == BinaryOperator::Eq {
                is_equal
            } else {
                !is_equal
            };
            return Ok(KclValue::Bool { value, meta });
        }

        // Enums compare by declaration and variant. This has to precede
        // `number_as_f64` below, which would otherwise reject an enum with
        // "expected a number" and describe the wrong problem.
        if matches!(self.operator, BinaryOperator::Eq | BinaryOperator::Neq) {
            match (&left_value, &right_value) {
                (KclValue::Enum { value: left }, KclValue::Enum { value: right }) => {
                    if left.enum_id() != right.enum_id() {
                        return Err(different_enums_err(left, right, self.as_source_range()));
                    }

                    let is_equal = left.variant() == right.variant();
                    let value = if self.operator == BinaryOperator::Eq {
                        is_equal
                    } else {
                        !is_equal
                    };
                    return Ok(KclValue::Bool { value, meta });
                }
                (KclValue::Enum { value }, other) | (other, KclValue::Enum { value }) => {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "Cannot compare enum `{}` with {}.",
                            value.qualified_name(),
                            other.human_friendly_type()
                        ),
                        vec![self.as_source_range()],
                    )));
                }
                _ => {}
            }
        }

        let left = number_as_f64(&left_value, self.left.clone().into())?;
        let right = number_as_f64(&right_value, self.right.clone().into())?;

        let value = match self.operator {
            BinaryOperator::Add => {
                let (l, r, ty) = NumericType::combine_eq_coerce(left, right, None);
                self.warn_on_unknown(&ty, "Adding", exec_state);
                KclValue::Number { value: l + r, meta, ty }
            }
            BinaryOperator::Sub => {
                let (l, r, ty) = NumericType::combine_eq_coerce(left, right, None);
                self.warn_on_unknown(&ty, "Subtracting", exec_state);
                KclValue::Number { value: l - r, meta, ty }
            }
            BinaryOperator::Mul => {
                let (l, r, ty) = NumericType::combine_mul(left, right);
                self.warn_on_unknown(&ty, "Multiplying", exec_state);
                KclValue::Number { value: l * r, meta, ty }
            }
            BinaryOperator::Div => {
                let (l, r, ty) = NumericType::combine_div(left, right);
                self.warn_on_unknown(&ty, "Dividing", exec_state);
                KclValue::Number { value: l / r, meta, ty }
            }
            BinaryOperator::Mod => {
                let (l, r, ty) = NumericType::combine_mod(left, right);
                self.warn_on_unknown(&ty, "Modulo of", exec_state);
                KclValue::Number { value: l % r, meta, ty }
            }
            BinaryOperator::Pow => KclValue::Number {
                value: libm::pow(left.n, right.n),
                meta,
                ty: exec_state.current_default_units(),
            },
            BinaryOperator::Neq => {
                let (l, r, ty) = NumericType::combine_eq(left, right, exec_state, self.as_source_range());
                self.warn_on_unknown(&ty, "Comparing", exec_state);
                KclValue::Bool { value: l != r, meta }
            }
            BinaryOperator::Gt => {
                let (l, r, ty) = NumericType::combine_eq(left, right, exec_state, self.as_source_range());
                self.warn_on_unknown(&ty, "Comparing", exec_state);
                KclValue::Bool { value: l > r, meta }
            }
            BinaryOperator::Gte => {
                let (l, r, ty) = NumericType::combine_eq(left, right, exec_state, self.as_source_range());
                self.warn_on_unknown(&ty, "Comparing", exec_state);
                KclValue::Bool { value: l >= r, meta }
            }
            BinaryOperator::Lt => {
                let (l, r, ty) = NumericType::combine_eq(left, right, exec_state, self.as_source_range());
                self.warn_on_unknown(&ty, "Comparing", exec_state);
                KclValue::Bool { value: l < r, meta }
            }
            BinaryOperator::Lte => {
                let (l, r, ty) = NumericType::combine_eq(left, right, exec_state, self.as_source_range());
                self.warn_on_unknown(&ty, "Comparing", exec_state);
                KclValue::Bool { value: l <= r, meta }
            }
            BinaryOperator::Eq => {
                let (l, r, ty) = NumericType::combine_eq(left, right, exec_state, self.as_source_range());
                self.warn_on_unknown(&ty, "Comparing", exec_state);
                KclValue::Bool { value: l == r, meta }
            }
            BinaryOperator::And | BinaryOperator::Or => unreachable!(),
        };

        Ok(value)
    }

    fn missing_result_error(node: &Node<BinaryExpression>) -> KclError {
        internal_err("missing result while evaluating binary expression", node)
    }

    fn warn_on_unknown(&self, ty: &NumericType, verb: &str, exec_state: &mut ExecState) {
        if ty == &NumericType::Unknown {
            let sr = self.as_source_range();
            exec_state.clear_units_warnings(&sr);
            let mut err = CompilationIssue::err(
                sr,
                format!(
                    "{verb} numbers which have unknown or incompatible units.\nYou can probably fix this error by specifying the units using type ascription, e.g., `len: number(mm)` or `(a * b): number(deg)`."
                ),
            );
            err.tag = crate::errors::Tag::UnknownNumericUnits;
            exec_state.warn(err, annotations::WARN_UNKNOWN_UNITS);
        }
    }
}

impl Node<UnaryExpression> {
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        let value = self.argument.get_result(exec_state, ctx).await?;
        let value = control_continue!(value);
        self.apply_unary(value, exec_state).map(KclValue::continue_)
    }

    /// Apply the unary operator to an already-evaluated operand. Shared by
    /// both executors.
    pub(super) fn apply_unary(&self, value: KclValue, exec_state: &mut ExecState) -> Result<KclValue, KclError> {
        match self.operator {
            UnaryOperator::Not => {
                let KclValue::Bool {
                    value: bool_value,
                    meta: _,
                } = value
                else {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "Cannot apply unary operator ! to non-boolean value: {}",
                            value.human_friendly_type()
                        ),
                        vec![self.into()],
                    )));
                };
                let meta = vec![Metadata {
                    source_range: self.into(),
                }];
                let negated = KclValue::Bool {
                    value: !bool_value,
                    meta,
                };

                Ok(negated)
            }
            UnaryOperator::Neg => {
                let err = || {
                    KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "You can only negate numbers, planes, or lines, but this is a {}",
                            value.human_friendly_type()
                        ),
                        vec![self.into()],
                    ))
                };
                match &value {
                    KclValue::Number { value, ty, .. } => {
                        let meta = vec![Metadata {
                            source_range: self.into(),
                        }];
                        Ok(KclValue::Number {
                            value: -value,
                            meta,
                            ty: *ty,
                        })
                    }
                    KclValue::Plane { value } => {
                        let mut plane = value.clone();
                        if plane.info.x_axis.x != 0.0 {
                            plane.info.x_axis.x *= -1.0;
                        }
                        if plane.info.x_axis.y != 0.0 {
                            plane.info.x_axis.y *= -1.0;
                        }
                        if plane.info.x_axis.z != 0.0 {
                            plane.info.x_axis.z *= -1.0;
                        }
                        plane.info.z_axis = plane.info.x_axis.axes_cross_product(&plane.info.y_axis);
                        plane.info.z_axis.canonicalize_signed_zero();

                        plane.id = exec_state.next_uuid();
                        plane.object_id = None;
                        Ok(KclValue::Plane { value: plane })
                    }
                    KclValue::Object {
                        value: values, meta, ..
                    } => {
                        // Special-case for negating line-like objects.
                        let Some(direction) = values.get("direction") else {
                            return Err(err());
                        };

                        let direction = match direction {
                            KclValue::Tuple { value: values, meta } => {
                                let values = values
                                    .iter()
                                    .map(|v| match v {
                                        KclValue::Number { value, ty, meta } => Ok(KclValue::Number {
                                            value: *value * -1.0,
                                            ty: *ty,
                                            meta: meta.clone(),
                                        }),
                                        _ => Err(err()),
                                    })
                                    .collect::<Result<Vec<_>, _>>()?;

                                KclValue::Tuple {
                                    value: values,
                                    meta: meta.clone(),
                                }
                            }
                            KclValue::HomArray {
                                value: values,
                                ty: ty @ RuntimeType::Primitive(PrimitiveType::Number(_)),
                            } => {
                                let values = values
                                    .iter()
                                    .map(|v| match v {
                                        KclValue::Number { value, ty, meta } => Ok(KclValue::Number {
                                            value: *value * -1.0,
                                            ty: *ty,
                                            meta: meta.clone(),
                                        }),
                                        _ => Err(err()),
                                    })
                                    .collect::<Result<Vec<_>, _>>()?;

                                KclValue::HomArray {
                                    value: values,
                                    ty: ty.clone(),
                                }
                            }
                            _ => return Err(err()),
                        };

                        let mut value = values.clone();
                        value.insert("direction".to_owned(), direction);
                        Ok(KclValue::Object {
                            value,
                            meta: meta.clone(),
                            constrainable: false,
                            object_kind: KclObjectKind::Default,
                        })
                    }
                    _ => Err(err()),
                }
            }
            UnaryOperator::Plus => match value {
                KclValue::Number { .. } | KclValue::Plane { .. } => Ok(value),
                _ => Err(KclError::new_semantic(KclErrorDetails::new(
                    format!(
                        "You can only apply unary + to numbers or planes, but this is a {}",
                        value.human_friendly_type()
                    ),
                    vec![self.into()],
                ))),
            },
        }
    }
}

pub(crate) async fn execute_pipe_body(
    exec_state: &mut ExecState,
    body: &[Expr],
    source_range: SourceRange,
    ctx: &ExecutorContext,
) -> Result<KclValueControlFlow, KclError> {
    let Some((first, body)) = body.split_first() else {
        return Err(KclError::new_semantic(KclErrorDetails::new(
            "Pipe expressions cannot be empty".to_owned(),
            vec![source_range],
        )));
    };
    // Evaluate the first element in the pipeline.
    // They use the pipe_value from some AST node above this, so that if pipe expression is nested in a larger pipe expression,
    // they use the % from the parent. After all, this pipe expression hasn't been executed yet, so it doesn't have any % value
    // of its own.
    let meta = Metadata {
        source_range: SourceRange::from(first),
    };
    let output = ctx
        .execute_expr(first, exec_state, &meta, &[], StatementKind::Expression)
        .await?;
    let output = control_continue!(output);

    // Now that we've evaluated the first child expression in the pipeline, following child expressions
    // should use the previous child expression for %.
    // This means there's no more need for the previous pipe_value from the parent AST node above this one.
    let previous_pipe_value = exec_state.mod_local.pipe_value.replace(output);
    // Evaluate remaining elements.
    let result = inner_execute_pipe_body(exec_state, body, ctx).await;
    // Restore the previous pipe value.
    exec_state.mod_local.pipe_value = previous_pipe_value;

    result
}

/// Execute the tail of a pipe expression.  exec_state.pipe_value must be set by
/// the caller.
#[async_recursion]
async fn inner_execute_pipe_body(
    exec_state: &mut ExecState,
    body: &[Expr],
    ctx: &ExecutorContext,
) -> Result<KclValueControlFlow, KclError> {
    for expression in body {
        if let Expr::TagDeclarator(_) = expression {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!("This cannot be in a PipeExpression: {expression:?}"),
                vec![expression.into()],
            )));
        }
        let metadata = Metadata {
            source_range: SourceRange::from(expression),
        };
        let output = ctx
            .execute_expr(expression, exec_state, &metadata, &[], StatementKind::Expression)
            .await?;
        let output = control_continue!(output);
        exec_state.mod_local.pipe_value = Some(output);
    }
    // Safe to unwrap here, because pipe_value always has something pushed in when the `match first` executes.
    let final_output = exec_state.mod_local.pipe_value.take().unwrap();
    Ok(final_output.continue_())
}

impl Node<TagDeclarator> {
    pub async fn execute(&self, exec_state: &mut ExecState) -> Result<KclValue, KclError> {
        let memory_item = KclValue::TagIdentifier(Box::new(TagIdentifier {
            value: self.name.clone(),
            info: Vec::new(),
            meta: vec![Metadata {
                source_range: self.into(),
            }],
        }));

        exec_state
            .mut_stack()
            .add(self.name.clone(), memory_item, self.into())?;

        Ok(self.into())
    }
}

impl Node<ArrayExpression> {
    #[async_recursion]
    pub(super) async fn execute(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        let mut results = Vec::with_capacity(self.elements.len());

        for element in &self.elements {
            let metadata = Metadata::from(element);
            // TODO: Carry statement kind here so that we know if we're
            // inside a variable declaration.
            let value = ctx
                .execute_expr(element, exec_state, &metadata, &[], StatementKind::Expression)
                .await?;
            let value = control_continue!(value);

            results.push(value);
        }

        Ok(KclValue::HomArray {
            value: results,
            ty: RuntimeType::Primitive(PrimitiveType::Any),
        }
        .continue_())
    }
}

impl Node<ArrayRangeExpression> {
    #[async_recursion]
    pub(super) async fn execute(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        let metadata = Metadata::from(&self.start_element);
        let start_val = ctx
            .execute_expr(
                &self.start_element,
                exec_state,
                &metadata,
                &[],
                StatementKind::Expression,
            )
            .await?;
        let start_val_for_build = control_continue!(start_val);
        self.validate_range_start(&start_val_for_build)?;
        let metadata = Metadata::from(&self.end_element);
        let end_val = ctx
            .execute_expr(&self.end_element, exec_state, &metadata, &[], StatementKind::Expression)
            .await?;
        let end_val = control_continue!(end_val);
        self.build_range(start_val_for_build, end_val, exec_state)
            .map(KclValue::continue_)
    }

    /// Validate the evaluated start endpoint, preserving the original error
    /// ordering: a bad start is reported before the end element is ever
    /// evaluated. Shared by both executors; `build_range` re-checks it,
    /// which is redundant but keeps `build_range` total on its own.
    pub(super) fn validate_range_start(&self, start_val: &KclValue) -> Result<(), KclError> {
        if start_val.as_ty_f64().is_none() {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!(
                    "Expected number for range start but found {}",
                    start_val.human_friendly_type()
                ),
                vec![self.into()],
            )));
        }
        Ok(())
    }

    /// Build the range value from evaluated endpoints. The evaluation-free
    /// second half of range execution, shared by both executors.
    pub(super) fn build_range(
        &self,
        start_val: KclValue,
        end_val: KclValue,
        exec_state: &mut ExecState,
    ) -> Result<KclValue, KclError> {
        let start = start_val
            .as_ty_f64()
            .ok_or(KclError::new_semantic(KclErrorDetails::new(
                format!(
                    "Expected number for range start but found {}",
                    start_val.human_friendly_type()
                ),
                vec![self.into()],
            )))?;
        let end = end_val.as_ty_f64().ok_or(KclError::new_semantic(KclErrorDetails::new(
            format!(
                "Expected number for range end but found {}",
                end_val.human_friendly_type()
            ),
            vec![self.into()],
        )))?;

        let (start, end, ty) = NumericType::combine_range(start, end, exec_state, self.as_source_range())?;
        let Some(start) = crate::try_f64_to_i64(start) else {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!("Range start must be an integer, but found {start}"),
                vec![self.into()],
            )));
        };
        let Some(end) = crate::try_f64_to_i64(end) else {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!("Range end must be an integer, but found {end}"),
                vec![self.into()],
            )));
        };

        if end < start {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!("Range start is greater than range end: {start} .. {end}"),
                vec![self.into()],
            )));
        }

        let range: Vec<_> = if self.end_inclusive {
            (start..=end).collect()
        } else {
            (start..end).collect()
        };

        let meta = vec![Metadata {
            source_range: self.into(),
        }];

        Ok(KclValue::HomArray {
            value: range
                .into_iter()
                .map(|num| KclValue::Number {
                    value: num as f64,
                    ty,
                    meta: meta.clone(),
                })
                .collect(),
            ty: RuntimeType::Primitive(PrimitiveType::Number(ty)),
        })
    }
}

impl Node<ObjectExpression> {
    #[async_recursion]
    pub(super) async fn execute(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        let mut object = HashMap::with_capacity(self.properties.len());
        for property in &self.properties {
            let metadata = Metadata::from(&property.value);
            let result = ctx
                .execute_expr(&property.value, exec_state, &metadata, &[], StatementKind::Expression)
                .await?;
            let result = control_continue!(result);
            object.insert(property.key.name.clone(), result);
        }

        Ok(KclValue::Object {
            value: object,
            meta: vec![Metadata {
                source_range: self.into(),
            }],
            constrainable: false,
            object_kind: KclObjectKind::Default,
        }
        .continue_())
    }
}

fn article_for<S: AsRef<str>>(s: S) -> &'static str {
    // '[' is included since it's an array.
    if s.as_ref().starts_with(['a', 'e', 'i', 'o', 'u', '[']) {
        "an"
    } else {
        "a"
    }
}

fn number_as_f64(v: &KclValue, source_range: SourceRange) -> Result<TyF64, KclError> {
    v.as_ty_f64().ok_or_else(|| {
        let actual_type = v.human_friendly_type();
        KclError::new_semantic(KclErrorDetails::new(
            format!("Expected a number, but found {actual_type}",),
            vec![source_range],
        ))
    })
}

impl Node<IfExpression> {
    #[async_recursion]
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        // Check the `if` branch. Conditions are evaluated in the enclosing
        // scope; only arm bodies get their own scope (under KCL 3.0).
        let cond_value = ctx
            .execute_expr(
                &self.cond,
                exec_state,
                &Metadata::from(self),
                &[],
                StatementKind::Expression,
            )
            .await?;
        let cond_value = control_continue!(cond_value);
        if cond_value.get_bool()? {
            return exec_if_arm(ctx, &self.then_val, exec_state).await;
        }

        // Check any `else if` branches.
        for else_if in &self.else_ifs {
            let cond_value = ctx
                .execute_expr(
                    &else_if.cond,
                    exec_state,
                    &Metadata::from(self),
                    &[],
                    StatementKind::Expression,
                )
                .await?;
            let cond_value = control_continue!(cond_value);
            if cond_value.get_bool()? {
                return exec_if_arm(ctx, &else_if.then_val, exec_state).await;
            }
        }

        // Run the final `else` branch.
        exec_if_arm(ctx, &self.final_else, exec_state).await
    }
}

/// Begin an if-arm scope. Under a KCL 3.0 entry point, each
/// if/else-if/else arm body gets its own scope: bindings made inside the arm
/// are visible from their declaration to the arm's closing brace, never
/// outside it, and may shadow bindings from enclosing scopes. Under older
/// entry points the arm shares the enclosing environment (bindings leak out
/// and shadowing is a redefinition error). Returns whether a scope
/// environment was pushed; the caller must pop it on every path. Shared by
/// both executors.
pub(super) fn if_arm_scope_begin(exec_state: &mut ExecState) -> Result<bool, KclError> {
    if !exec_state.entry_point_version_is_v3_or_higher() {
        return Ok(false);
    }
    exec_state.mut_stack().push_new_env_for_block()?;
    Ok(true)
}

/// Execute one if/else-if/else arm body in its own scope (under a
/// KCL 3.0 entry point). Values escaping the arm -- including closures
/// declared in it -- stay valid after the pop because environments that may
/// still be referenced are preserved, exactly as for function returns.
async fn exec_if_arm(
    ctx: &ExecutorContext,
    block: &Node<Program>,
    exec_state: &mut ExecState,
) -> Result<KclValueControlFlow, KclError> {
    let scoped = if_arm_scope_begin(exec_state)?;
    let result = ctx.exec_block(block, exec_state, BodyType::Block).await;
    if scoped {
        // Pop on success (including Return/Exit control flow escaping the
        // arm) and error alike. A pop failure wins over the block's error,
        // matching call_abort_on_arg_binding_failure.
        exec_state.mut_stack().pop_env()?;
    }
    // Block must end in an expression, so this is always Some.
    // Enforced by the parser.
    // See https://github.com/KittyCAD/modeling-app/issues/4015
    let Some(cf) = result? else {
        let message = "if-expression arm produced no value";
        debug_assert!(false, "{message}");
        return Err(KclError::new_internal(KclErrorDetails::new(
            message.to_owned(),
            vec![block.to_source_range()],
        )));
    };
    Ok(cf)
}

#[derive(Debug)]
pub(super) enum Property {
    UInt(usize),
    String(String),
}

impl Property {
    #[allow(clippy::too_many_arguments)]
    async fn try_from<'a>(
        computed: bool,
        value: Expr,
        exec_state: &mut ExecState,
        sr: SourceRange,
        ctx: &ExecutorContext,
        metadata: &Metadata,
        annotations: &[Node<Annotation>],
        statement_kind: StatementKind<'a>,
    ) -> Result<Self, EarlyReturn> {
        if !computed {
            return Ok(Self::from_static_name(&value, sr)?);
        }

        let prop_value = ctx
            .execute_expr(&value, exec_state, metadata, annotations, statement_kind)
            .await?;
        // If the property expression exited, e.g. by calling exit(), propagate
        // the exit so that it terminates the enclosing module.
        let prop_value = early_return!(prop_value);
        Ok(Self::from_value(prop_value, sr)?)
    }

    /// Convert a non-computed property (the identifier in `obj.property`)
    /// into a Property. Nothing is evaluated. Shared by both executors.
    pub(super) fn from_static_name(property: &Expr, sr: SourceRange) -> Result<Self, KclError> {
        let Expr::Name(identifier) = property else {
            // Should actually be impossible because the parser would reject it.
            return Err(KclError::new_semantic(KclErrorDetails::new(
                "Object expressions like `obj.property` must use simple identifier names, not complex expressions"
                    .to_owned(),
                vec![sr],
            )));
        };
        Ok(Property::String(identifier.to_string()))
    }

    /// Convert an already-evaluated computed-property value (the expression
    /// inside array brackets) into a Property. Shared by both executors.
    pub(super) fn from_value(prop_value: KclValue, sr: SourceRange) -> Result<Self, KclError> {
        let property_sr = vec![sr];
        match prop_value {
            KclValue::Number { value, ty, meta: _ } => {
                if !matches!(
                    ty,
                    NumericType::Unknown
                        | NumericType::Default { .. }
                        | NumericType::Known(crate::exec::UnitType::Count)
                ) {
                    return Err(KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "{value} is not a valid index, indices must be non-dimensional numbers. If you're sure this is correct, you can add `: number(Count)` to tell KCL this number is an index"
                        ),
                        property_sr,
                    )));
                }
                if let Some(x) = crate::try_f64_to_usize(value) {
                    Ok(Property::UInt(x))
                } else {
                    Err(KclError::new_semantic(KclErrorDetails::new(
                        format!("{value} is not a valid index, indices must be whole numbers >= 0"),
                        property_sr,
                    )))
                }
            }
            _ => Err(KclError::new_semantic(KclErrorDetails::new(
                "Only numbers (>= 0) can be indexes".to_owned(),
                vec![sr],
            ))),
        }
    }
}

impl Property {
    fn type_name(&self) -> &'static str {
        match self {
            Property::UInt(_) => "number",
            Property::String(_) => "string",
        }
    }
}

impl Node<PipeExpression> {
    #[async_recursion]
    pub(super) async fn get_result(
        &self,
        exec_state: &mut ExecState,
        ctx: &ExecutorContext,
    ) -> Result<KclValueControlFlow, KclError> {
        execute_pipe_body(exec_state, &self.body, self.into(), ctx).await
    }
}

#[cfg(test)]
mod test {
    use std::sync::Arc;

    use kcl_api::UnitLength;
    use tokio::io::AsyncWriteExt;

    use super::*;
    use crate::ExecutorSettings;
    use crate::engine::engine_manager;
    use crate::errors::Severity;
    use crate::exec::UnitType;
    use crate::execution::ContextType;
    use crate::execution::machine::ExecutorKind;
    use crate::execution::parse_execute;

    fn assert_angle_degrees(actual: ezpz::datatypes::Angle, expected: f64) {
        assert!(
            (actual.to_degrees() - expected).abs() < 1e-9,
            "expected {expected}deg, got {}deg",
            actual.to_degrees()
        );
    }

    #[test]
    fn remaps_sector_angles_to_existing_representative_endpoint_rays() {
        let representative_directions = [AngleRayDirection::Forward, AngleRayDirection::Forward];

        assert_angle_degrees(
            remap_angle_for_representative_rays(
                angle_sector_rays(AngleSector::One, false),
                representative_directions,
                ezpz::datatypes::Angle::from_degrees(60.0),
            ),
            60.0,
        );
        assert_angle_degrees(
            remap_angle_for_representative_rays(
                angle_sector_rays(AngleSector::Two, false),
                representative_directions,
                ezpz::datatypes::Angle::from_degrees(120.0),
            ),
            60.0,
        );
        assert_angle_degrees(
            remap_angle_for_representative_rays(
                angle_sector_rays(AngleSector::Three, false),
                representative_directions,
                ezpz::datatypes::Angle::from_degrees(60.0),
            ),
            60.0,
        );
        assert_angle_degrees(
            remap_angle_for_representative_rays(
                angle_sector_rays(AngleSector::Four, false),
                representative_directions,
                ezpz::datatypes::Angle::from_degrees(120.0),
            ),
            60.0,
        );
        assert_angle_degrees(
            remap_angle_for_representative_rays(
                angle_sector_rays(AngleSector::One, true),
                representative_directions,
                ezpz::datatypes::Angle::from_degrees(300.0),
            ),
            60.0,
        );
    }

    #[test]
    fn remaps_sector_angles_when_representative_endpoint_is_on_reverse_ray() {
        assert_angle_degrees(
            remap_angle_for_representative_rays(
                angle_sector_rays(AngleSector::One, false),
                [AngleRayDirection::Forward, AngleRayDirection::Reverse],
                ezpz::datatypes::Angle::from_degrees(60.0),
            ),
            240.0,
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_unlabeled_keeps_legacy_lines_at_angle() {
        let code = r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var 2mm, var 3.464mm])
  lines = [line1, line2]
  angle(lines) == 60deg
}
"#;
        let result = parse_execute(code).await.unwrap();

        let metadata = result
            .exec_state
            .global
            .root_module_artifacts
            .legacy_angle_refactor_metadata();
        assert_eq!(metadata.len(), 1);
        assert_eq!(metadata[0].sector, 1);
        assert!(!metadata[0].inverse);
        let program = crate::Program::parse_no_errs(code).unwrap();
        let findings = program.lint(crate::lint::checks::lint_legacy_angle).unwrap();
        assert_eq!(metadata[0].source_range, findings[0].pos);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn legacy_angle_refactor_metadata_matches_the_default_label_side() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var -2mm, var -3.464mm])
  angle([line1, line2]) == 60deg
}
"#,
        )
        .await
        .unwrap();

        let metadata = result
            .exec_state
            .global
            .root_module_artifacts
            .legacy_angle_refactor_metadata();
        assert_eq!(metadata.len(), 1);
        assert_eq!(metadata[0].sector, 4);
        assert!(metadata[0].inverse);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn legacy_angle_refactor_metadata_uses_reverse_segment_rays() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var -4mm, var 0mm], end = [var 0mm, var 0mm])
  line2 = line(start = [var -2mm, var -3.464mm], end = [var 0mm, var 0mm])
  angle([line1, line2]) == 60deg
}
"#,
        )
        .await
        .unwrap();

        let metadata = result
            .exec_state
            .global
            .root_module_artifacts
            .legacy_angle_refactor_metadata();
        assert_eq!(metadata.len(), 1);
        assert_eq!(metadata[0].sector, 3);
        assert!(!metadata[0].inverse);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn legacy_angle_label_position_does_not_change_the_sector() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var 2mm, var 3.464mm])
  angle([line1, line2], labelPosition = [-3mm, -1.7mm]) == 60deg
}
"#,
        )
        .await
        .unwrap();

        let metadata = result
            .exec_state
            .global
            .root_module_artifacts
            .legacy_angle_refactor_metadata();
        assert_eq!(metadata.len(), 1);
        assert_eq!(metadata[0].sector, 1);
        assert!(!metadata[0].inverse);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn parallel_legacy_angle_has_no_refactor_metadata() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 1mm], end = [var 4mm, var 1mm])
  angle([line1, line2]) == 0deg
}
"#,
        )
        .await
        .unwrap();

        assert!(
            result
                .exec_state
                .global
                .root_module_artifacts
                .legacy_angle_refactor_metadata()
                .is_empty()
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_with_sector_uses_named_lines() {
        parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 1mm], end = [var 2mm, var 3mm])
  angleDimension(lines = [line1, line2], sector = 2) == 60deg
}
"#,
        )
        .await
        .unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_requires_sector() {
        let err = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var 2mm, var 3.464mm])
  angleDimension(lines = [line1, line2]) == 60deg
}
"#,
        )
        .await
        .unwrap_err();

        assert!(
            err.to_string()
                .contains("The `angleDimension` function requires a keyword argument `sector`"),
            "unexpected error: {err:?}"
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_accepts_label_position() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var 2mm, var 3.464mm])
  angleDimension(lines = [line1, line2], sector = 1, labelPosition = [10mm, 11mm]) == 60deg
}
"#,
        )
        .await
        .unwrap();
        let angle = result
            .exec_state
            .global
            .root_module_artifacts
            .scene_objects
            .iter()
            .find_map(|object| match &object.kind {
                ObjectKind::Constraint {
                    constraint: crate::front::Constraint::Angle(angle),
                } => Some(angle),
                _ => None,
            })
            .unwrap();
        let label_position = angle.label_position.as_ref().unwrap();
        assert_eq!(label_position.x.value, 10.0);
        assert_eq!(label_position.y.value, 11.0);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_accepts_all_four_sectors() {
        parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var 2mm, var 3.464mm])
  angleDimension(lines = [line1, line2], sector = 1) == 60deg
  angleDimension(lines = [line1, line2], sector = 2) == 120deg
  angleDimension(lines = [line1, line2], sector = 3) == 60deg
  angleDimension(lines = [line1, line2], sector = 4) == 120deg
}
"#,
        )
        .await
        .unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_accepts_inverse_angle_for_sector() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 0mm], end = [var 2mm, var 3.464mm])
  angleDimension(lines = [line1, line2], sector = 1, inverse = true) == 360deg - 60deg
}
"#,
        )
        .await
        .unwrap();
        let angle = result
            .exec_state
            .global
            .root_module_artifacts
            .scene_objects
            .iter()
            .find_map(|object| match &object.kind {
                ObjectKind::Constraint {
                    constraint: crate::front::Constraint::Angle(angle),
                } => Some(angle),
                _ => None,
            })
            .unwrap();
        assert_eq!(angle.sector, Some(1));
        assert_eq!(angle.inverse, Some(true));
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_rejects_invalid_sector() {
        let err = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 1mm], end = [var 2mm, var 3mm])
  angleDimension(lines = [line1, line2], sector = 5) == 60deg
}
"#,
        )
        .await
        .unwrap_err();

        assert!(
            err.to_string()
                .contains("angleDimension() sector must be 1, 2, 3, or 4"),
            "unexpected error: {err:?}"
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_dimension_rejects_parallel_lines() {
        let err = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 1mm], end = [var 4mm, var 1mm])
  angleDimension(lines = [line1, line2], sector = 2) == 60deg
}
"#,
        )
        .await
        .unwrap_err();

        assert!(
            err.to_string()
                .contains("angleDimension(lines = ..., sector = ...) requires non-parallel lines"),
            "unexpected error: {err:?}"
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_accepts_label_position() {
        let result = parse_execute(
            r#"
sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 4mm, var 0mm])
  line2 = line(start = [var 0mm, var 1mm], end = [var 2mm, var 3mm])
  angle([line1, line2], labelPosition = [10mm, 11mm]) == 60deg
}
"#,
        )
        .await
        .unwrap();
        let angle = result
            .exec_state
            .global
            .root_module_artifacts
            .scene_objects
            .iter()
            .find_map(|object| match &object.kind {
                ObjectKind::Constraint {
                    constraint: crate::front::Constraint::Angle(angle),
                } => Some(angle),
                _ => None,
            })
            .unwrap();
        let label_position = angle.label_position.as_ref().unwrap();
        assert_eq!(label_position.x.value, 10.0);
        assert_eq!(label_position.y.value, 11.0);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn angle_requires_unlabeled_lines() {
        parse_execute(
            r#"
sketch(on = XY) {
  angle() == 60deg
}
"#,
        )
        .await
        .unwrap_err();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn ascription() {
        let program = r#"
a = 42: number
b = a: number
p = {
  origin = { x = 0, y = 0, z = 0 },
  xAxis = { x = 1, y = 0, z = 0 },
  yAxis = { x = 0, y = 1, z = 0 },
  zAxis = { x = 0, y = 0, z = 1 }
}: Plane
arr1 = [42]: [number(cm)]
"#;

        let result = parse_execute(program).await.unwrap();
        let mem = result.exec_state.stack();
        assert!(matches!(
            mem.memory
                .get_from_owned("p", result.mem_env, SourceRange::default(), 0)
                .unwrap(),
            KclValue::Plane { .. }
        ));
        let arr1 = mem
            .memory
            .get_from_owned("arr1", result.mem_env, SourceRange::default(), 0)
            .unwrap();
        if let KclValue::HomArray { value, ty } = arr1 {
            assert_eq!(value.len(), 1, "Expected Vec with specific length: found {value:?}");
            assert_eq!(ty, RuntimeType::known_length(UnitLength::Centimeters));
            // Compare, ignoring meta.
            if let KclValue::Number { value, ty, .. } = &value[0] {
                // It should not convert units.
                assert_eq!(*value, 42.0);
                assert_eq!(*ty, NumericType::Known(UnitType::Length(UnitLength::Centimeters)));
            } else {
                panic!("Expected a number; found {:?}", value[0]);
            }
        } else {
            panic!("Expected HomArray; found {arr1:?}");
        }

        let program = r#"
a = 42: string
"#;
        let result = parse_execute(program).await;
        let err = result.unwrap_err();
        assert!(
            err.to_string()
                .contains("could not coerce a number (with type `number`) to type `string`"),
            "Expected error but found {err:?}"
        );

        let program = r#"
a = 42: Plane
"#;
        let result = parse_execute(program).await;
        let err = result.unwrap_err();
        assert!(
            err.to_string()
                .contains("could not coerce a number (with type `number`) to type `Plane`"),
            "Expected error but found {err:?}"
        );

        let program = r#"
arr = [0]: [string]
"#;
        let result = parse_execute(program).await;
        let err = result.unwrap_err();
        assert!(
            err.to_string().contains(
                "could not coerce an array of `number` with 1 value (with type `[any; 1]`) to type `[string]`"
            ),
            "Expected error but found {err:?}"
        );

        let program = r#"
mixedArr = [0, "a"]: [number(mm)]
"#;
        let result = parse_execute(program).await;
        let err = result.unwrap_err();
        assert!(
            err.to_string().contains(
                "could not coerce an array of `number`, `string` (with type `[any; 2]`) to type `[number(mm)]`"
            ),
            "Expected error but found {err:?}"
        );

        let program = r#"
mixedArr = [0, "a"]: [mm]
"#;
        let result = parse_execute(program).await;
        let err = result.unwrap_err();
        assert!(
            err.to_string().contains(
                "could not coerce an array of `number`, `string` (with type `[any; 2]`) to type `[number(mm)]`"
            ),
            "Expected error but found {err:?}"
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn neg_plane() {
        let program = r#"
p = {
  origin = { x = 0, y = 0, z = 0 },
  xAxis = { x = 1, y = 0, z = 0 },
  yAxis = { x = 0, y = 1, z = 0 },
}: Plane
p2 = -p
"#;

        let result = parse_execute(program).await.unwrap();
        let mem = result.exec_state.stack();
        match mem
            .memory
            .get_from_owned("p2", result.mem_env, SourceRange::default(), 0)
            .unwrap()
        {
            KclValue::Plane { value } => {
                assert_eq!(value.info.x_axis.x, -1.0);
                assert_eq!(value.info.x_axis.y, 0.0);
                assert_eq!(value.info.x_axis.z, 0.0);
            }
            _ => unreachable!(),
        }
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn multiple_returns() {
        let program = r#"fn foo() {
  return 0
  return 42
}

a = foo()
"#;

        let result = parse_execute(program).await;
        assert!(result.unwrap_err().to_string().contains("return"));
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn load_all_modules() {
        // program a.kcl
        let program_a_kcl = r#"
export a = 1
"#;
        // program b.kcl
        let program_b_kcl = r#"
import a from 'a.kcl'

export b = a + 1
"#;
        // program c.kcl
        let program_c_kcl = r#"
import a from 'a.kcl'

export c = a + 2
"#;

        // program main.kcl
        let main_kcl = r#"
import b from 'b.kcl'
import c from 'c.kcl'

d = b + c
"#;

        let main = crate::parsing::parse_str(main_kcl, ModuleId::default())
            .parse_errs_as_err()
            .unwrap();

        let tmpdir = tempfile::TempDir::with_prefix("zma_kcl_load_all_modules").unwrap();

        tokio::fs::File::create(tmpdir.path().join("main.kcl"))
            .await
            .unwrap()
            .write_all(main_kcl.as_bytes())
            .await
            .unwrap();

        tokio::fs::File::create(tmpdir.path().join("a.kcl"))
            .await
            .unwrap()
            .write_all(program_a_kcl.as_bytes())
            .await
            .unwrap();

        tokio::fs::File::create(tmpdir.path().join("b.kcl"))
            .await
            .unwrap()
            .write_all(program_b_kcl.as_bytes())
            .await
            .unwrap();

        tokio::fs::File::create(tmpdir.path().join("c.kcl"))
            .await
            .unwrap()
            .write_all(program_c_kcl.as_bytes())
            .await
            .unwrap();

        let exec_ctxt = ExecutorContext {
            engine: Arc::new(engine_manager::EngineManager::new_mock()),
            engine_batch: crate::engine::EngineBatchContext::default(),
            fs: crate::fs::new_file_system_handle(crate::fs::FileManager::new()),
            settings: ExecutorSettings {
                project_directory: Some(crate::TypedPath(tmpdir.path().into())),
                ..Default::default()
            },
            context_type: ContextType::Mock,
            execution_callbacks: Default::default(),
            executor_kind: ExecutorKind::resolve(),
            machine_call_depth_limit: crate::execution::machine::DEFAULT_MACHINE_CALL_DEPTH_LIMIT,
        };
        let mut exec_state = ExecState::new(&exec_ctxt);

        exec_ctxt
            .run(
                &crate::Program {
                    ast: main.clone(),
                    original_file_contents: "".to_owned(),
                },
                &mut exec_state,
            )
            .await
            .unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn user_coercion() {
        let program = r#"fn foo(x: Axis2d) {
  return 0
}

foo(x = { direction = [0, 0], origin = [0, 0]})
"#;

        parse_execute(program).await.unwrap();

        let program = r#"fn foo(x: Axis3d) {
  return 0
}

foo(x = { direction = [0, 0], origin = [0, 0]})
"#;

        parse_execute(program).await.unwrap_err();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn coerce_return() {
        let program = r#"fn foo(): number(mm) {
  return 42
}

a = foo()
"#;

        parse_execute(program).await.unwrap();

        let program = r#"fn foo(): mm {
  return 42
}

a = foo()
"#;

        parse_execute(program).await.unwrap();

        let program = r#"fn foo(): number(mm) {
  return { bar: 42 }
}

a = foo()
"#;

        parse_execute(program).await.unwrap_err();

        let program = r#"fn foo(): mm {
  return { bar: 42 }
}

a = foo()
"#;

        parse_execute(program).await.unwrap_err();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn test_sensible_error_when_missing_equals_in_kwarg() {
        for (i, call) in ["f(x=1,3,0)", "f(x=1,3,z)", "f(x=1,0,z=1)", "f(x=1, 3 + 4, z)"]
            .into_iter()
            .enumerate()
        {
            let program = format!(
                "fn foo() {{ return 0 }}
z = 0
fn f(x, y, z) {{ return 0 }}
{call}"
            );
            let err = parse_execute(&program).await.unwrap_err();
            let msg = err.message();
            assert!(
                msg.contains("This argument needs a label, but it doesn't have one"),
                "failed test {i}: {msg}"
            );
            assert!(msg.contains("`y`"), "failed test {i}, missing `y`: {msg}");
            if i == 0 {
                assert!(msg.contains("`z`"), "failed test {i}, missing `z`: {msg}");
            }
        }
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn default_param_for_unlabeled() {
        // Tests that the input param for myExtrude is taken from the pipeline value and same-name
        // keyword args.
        let ast = r#"fn myExtrude(@sk, length) {
  return extrude(sk, length)
}
sketch001 = startSketchOn(XY)
  |> circle(center = [0, 0], radius = 93.75)
  |> myExtrude(length = 40)
"#;

        parse_execute(ast).await.unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn dont_use_unlabelled_as_input() {
        // `length` should be used as the `length` argument to extrude, not the unlabelled input
        let ast = r#"length = 10
startSketchOn(XY)
  |> circle(center = [0, 0], radius = 93.75)
  |> extrude(length)
"#;

        parse_execute(ast).await.unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn ascription_in_binop() {
        let ast = r#"foo = tan(0): number(rad) - 4deg"#;
        parse_execute(ast).await.unwrap();

        let ast = r#"foo = tan(0): rad - 4deg"#;
        parse_execute(ast).await.unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn neg_sqrt() {
        let ast = r#"bad = sqrt(-2)"#;

        let e = parse_execute(ast).await.unwrap_err();
        // Make sure we get a useful error message and not an engine error.
        assert!(e.message().contains("sqrt"), "Error message: '{}'", e.message());
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn non_array_fns() {
        let ast = r#"push(1, item = 2)
pop(1)
map(1, f = fn(@x) { return x + 1 })
reduce(1, f = fn(@x, accum) { return accum + x}, initial = 0)"#;

        parse_execute(ast).await.unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn non_array_indexing() {
        let good = r#"a = 42
good = a[0]
"#;
        let result = parse_execute(good).await.unwrap();
        let mem = result.exec_state.stack();
        let num = mem
            .memory
            .get_from_owned("good", result.mem_env, SourceRange::default(), 0)
            .unwrap()
            .as_ty_f64()
            .unwrap();
        assert_eq!(num.n, 42.0);

        let bad = r#"a = 42
bad = a[1]
"#;

        parse_execute(bad).await.unwrap_err();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn coerce_unknown_to_length() {
        let ast = r#"x = 2mm * 2mm
y = x: number(Length)"#;
        let e = parse_execute(ast).await.unwrap_err();
        assert!(
            e.message().contains("could not coerce"),
            "Error message: '{}'",
            e.message()
        );

        let ast = r#"x = 2mm
y = x: number(Length)"#;
        let result = parse_execute(ast).await.unwrap();
        let mem = result.exec_state.stack();
        let num = mem
            .memory
            .get_from_owned("y", result.mem_env, SourceRange::default(), 0)
            .unwrap()
            .as_ty_f64()
            .unwrap();
        assert_eq!(num.n, 2.0);
        assert_eq!(num.ty, NumericType::mm());
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn one_warning_unknown() {
        let ast = r#"
// Should warn once
a = PI * 2
// Should warn once
b = (PI * 2) / 3
// Should not warn
c = ((PI * 2) / 3): number(deg)
"#;

        let result = parse_execute(ast).await.unwrap();
        assert_eq!(result.exec_state.issues().len(), 2);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn non_count_indexing() {
        let ast = r#"x = [0, 0]
y = x[1mm]
"#;
        parse_execute(ast).await.unwrap_err();

        let ast = r#"x = [0, 0]
y = 1deg
z = x[y]
"#;
        parse_execute(ast).await.unwrap_err();

        let ast = r#"x = [0, 0]
y = x[0mm + 1]
"#;
        parse_execute(ast).await.unwrap_err();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn getting_property_of_plane() {
        let ast = std::fs::read_to_string("tests/inputs/planestuff.kcl").unwrap();
        parse_execute(&ast).await.unwrap();
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn no_artifacts_from_within_hole_call() {
        // Test that executing stdlib KCL, like the `hole` function
        // (which is actually implemented in KCL not Rust)
        // does not generate artifacts from within the stdlib code,
        // only from the user code.
        let ast = std::fs::read_to_string("tests/inputs/sample_hole.kcl").unwrap();
        let out = parse_execute(&ast).await.unwrap();

        // Get all the operations that occurred.
        let actual_operations = out.exec_state.global.root_module_artifacts.operations;

        // There should be 5, for sketching the cube and applying the hole.
        // If the stdlib internal calls are being tracked, that's a bug,
        // and the actual number of operations will be something like 35.
        let expected = 5;
        assert_eq!(
            actual_operations.len(),
            expected,
            "expected {expected} operations, received {}:\n{actual_operations:#?}",
            actual_operations.len(),
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn feature_tree_annotation_on_user_defined_kcl() {
        // The call to foo() should not generate an operation,
        // because its 'feature_tree' attribute has been set to false.
        let ast = std::fs::read_to_string("tests/inputs/feature_tree_annotation_on_user_defined_kcl.kcl").unwrap();
        let out = parse_execute(&ast).await.unwrap();

        // Get all the operations that occurred.
        let actual_operations = out.exec_state.global.root_module_artifacts.operations;

        let expected = 0;
        assert_eq!(
            actual_operations.len(),
            expected,
            "expected {expected} operations, received {}:\n{actual_operations:#?}",
            actual_operations.len(),
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn no_feature_tree_annotation_on_user_defined_kcl() {
        // The call to foo() should generate an operation,
        // because @(feature_tree) defaults to true.
        let ast = std::fs::read_to_string("tests/inputs/no_feature_tree_annotation_on_user_defined_kcl.kcl").unwrap();
        let out = parse_execute(&ast).await.unwrap();

        // Get all the operations that occurred.
        let actual_operations = out.exec_state.global.root_module_artifacts.operations;

        let expected = 2;
        assert_eq!(
            actual_operations.len(),
            expected,
            "expected {expected} operations, received {}:\n{actual_operations:#?}",
            actual_operations.len(),
        );
        assert!(matches!(actual_operations[0], Operation::GroupBegin { .. }));
        assert!(matches!(actual_operations[1], Operation::GroupEnd));
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn custom_warning() {
        let warn = r#"
a = PI * 2
"#;
        let result = parse_execute(warn).await.unwrap();
        assert_eq!(result.exec_state.issues().len(), 1);
        assert_eq!(result.exec_state.issues()[0].severity, Severity::Warning);

        let allow = r#"
@warnings(allow = unknownUnits)
a = PI * 2
"#;
        let result = parse_execute(allow).await.unwrap();
        assert_eq!(result.exec_state.issues().len(), 0);

        let deny = r#"
@warnings(deny = [unknownUnits])
a = PI * 2
"#;
        let result = parse_execute(deny).await.unwrap();
        assert_eq!(result.exec_state.issues().len(), 1);
        assert_eq!(result.exec_state.issues()[0].severity, Severity::Error);
    }

    /// KCL 3.0 renamed `@warnings` to `@diagnostics`. Under KCL 3.0-preview
    /// or later, `@diagnostics` customizes diagnostics the way `@warnings`
    /// does in earlier versions.
    #[tokio::test(flavor = "multi_thread")]
    async fn diagnostics_attribute_in_v3() {
        let warn = "@settings(kclVersion = \"3.0-preview\")\na = PI * 2\n";
        let result = parse_execute(warn).await.unwrap();
        let issues = result.exec_state.issues();
        assert_eq!(issues.len(), 1, "{issues:#?}");
        assert_eq!(issues[0].severity, Severity::Warning);
        assert_eq!(issues[0].tag, crate::errors::Tag::UnknownNumericUnits);

        let allow = "@settings(kclVersion = \"3.0-preview\")\n@diagnostics(allow = unknownUnits)\na = PI * 2\n";
        let result = parse_execute(allow).await.unwrap();
        assert!(
            result.exec_state.issues().is_empty(),
            "{:#?}",
            result.exec_state.issues()
        );

        let deny = "@settings(kclVersion = \"3.0-preview\")\n@diagnostics(deny = [unknownUnits])\na = PI * 2\n";
        let result = parse_execute(deny).await.unwrap();
        let issues = result.exec_state.issues();
        assert_eq!(issues.len(), 1, "{issues:#?}");
        assert_eq!(issues[0].severity, Severity::Error);
        assert_eq!(issues[0].tag, crate::errors::Tag::UnknownNumericUnits);
    }

    /// Before KCL 3.0, `@diagnostics` is not an attribute: it gets the usual
    /// unknown-annotation warning and has no effect, while `@warnings` keeps
    /// working.
    #[tokio::test(flavor = "multi_thread")]
    async fn diagnostics_attribute_is_unknown_before_v3() {
        for version in ["1.0", "2.0"] {
            let code = format!("@settings(kclVersion = {version})\n@diagnostics(allow = unknownUnits)\na = PI * 2\n");
            let result = parse_execute(&code).await.unwrap();
            let issues = result.exec_state.issues();
            assert_eq!(issues.len(), 2, "code={code}, issues={issues:#?}");
            assert_eq!(issues[0].severity, Severity::Warning);
            assert_eq!(issues[0].message, "Unknown annotation");
            assert_eq!(
                &code[issues[0].source_range.start()..issues[0].source_range.end()],
                "@diagnostics(allow = unknownUnits)"
            );
            assert_eq!(issues[1].severity, Severity::Warning);
            assert_eq!(issues[1].tag, crate::errors::Tag::UnknownNumericUnits);

            let code = format!("@settings(kclVersion = {version})\n@warnings(allow = unknownUnits)\na = PI * 2\n");
            let result = parse_execute(&code).await.unwrap();
            assert!(
                result.exec_state.issues().is_empty(),
                "code={code}, issues={:#?}",
                result.exec_state.issues()
            );
        }
    }

    /// Errors for a malformed attribute name the attribute that was written:
    /// `warnings` before KCL 3.0 and `diagnostics` in KCL 3.0-preview or
    /// later.
    #[tokio::test(flavor = "multi_thread")]
    async fn diagnostics_attribute_errors_use_the_attribute_name() {
        for (version, attr, noun) in [
            ("1.0", "warnings", "warning"),
            ("2.0", "warnings", "warning"),
            ("\"3.0-preview\"", "diagnostics", "diagnostic"),
        ] {
            let settings = format!("@settings(kclVersion = {version})\n");

            let code = format!("{settings}@{attr}\n");
            let error = parse_execute(&code).await.unwrap_err();
            assert_eq!(error.message(), format!("Empty `{attr}` annotation"), "code={code}");

            let code = format!("{settings}@{attr}(warn = unknownUnits)\n");
            let error = parse_execute(&code).await.unwrap_err();
            assert_eq!(
                error.message(),
                format!("Unexpected {attr} key: `warn`; expected one of `allow`, `deny`"),
                "code={code}"
            );

            let code = format!("{settings}@{attr}(allow = 1)\n");
            let error = parse_execute(&code).await.unwrap_err();
            assert_eq!(
                error.message(),
                format!(
                    "Unexpected {attr} value, expected a name or array of names, e.g., `unknownUnits` or `[unknownUnits, deprecated]`"
                ),
                "code={code}"
            );

            let code = format!("{settings}@{attr}(allow = bogus)\n");
            let error = parse_execute(&code).await.unwrap_err();
            let expected_prefix = format!("Unexpected {noun} value: `bogus`; accepted values: unknownUnits, ");
            assert!(
                error.message().starts_with(&expected_prefix),
                "code={code}, message={}",
                error.message()
            );
        }
    }

    /// KCL 3.0: using the old `@warnings` name is a non-fatal error that
    /// explains the rename and offers the fix. The attribute is ignored, so
    /// the warning it tried to allow is still reported.
    #[tokio::test(flavor = "multi_thread")]
    async fn warnings_attribute_is_renamed_in_v3() {
        let code = "@settings(kclVersion = \"3.0-preview\")\n@warnings(allow = unknownUnits)\na = PI * 2\n";
        let result = parse_execute(code).await.unwrap();
        let issues = result.exec_state.issues();
        assert_eq!(issues.len(), 2, "{issues:#?}");

        let renamed = &issues[0];
        assert_eq!(renamed.severity, Severity::Error);
        assert_eq!(
            renamed.message,
            "The `@warnings` attribute was renamed to `@diagnostics` in KCL 3.0, so this attribute is ignored. Replace `@warnings` with `@diagnostics`; its `allow` and `deny` properties are unchanged."
        );
        assert_eq!(
            &code[renamed.source_range.start()..renamed.source_range.end()],
            "@warnings(allow = unknownUnits)"
        );
        let suggestion = renamed.suggestion.as_ref().unwrap();
        assert_eq!(suggestion.title, "Rename to `@diagnostics`");
        assert_eq!(
            suggestion.apply(code),
            "@settings(kclVersion = \"3.0-preview\")\n@diagnostics(allow = unknownUnits)\na = PI * 2\n"
        );

        assert_eq!(issues[1].severity, Severity::Warning);
        assert_eq!(issues[1].tag, crate::errors::Tag::UnknownNumericUnits);

        // Since the attribute is ignored, its properties aren't checked.
        let code = "@settings(kclVersion = \"3.0-preview\")\n@warnings(allow = bogus)\n";
        let result = parse_execute(code).await.unwrap();
        let issues = result.exec_state.issues();
        assert_eq!(issues.len(), 1, "{issues:#?}");
        assert_eq!(issues[0].severity, Severity::Error);
        assert!(issues[0].message.starts_with("The `@warnings` attribute was renamed"));
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn sketch_block_unqualified_functions_use_sketch2() {
        let ast = r#"
s = sketch(on = XY) {
  line1 = line(start = [var 0mm, var 0mm], end = [var 1mm, var 0mm])
  line2 = line(start = [var 1mm, var 0mm], end = [var 1mm, var 1mm])
  coincident([line1.end, line2.start])
}
"#;
        let result = parse_execute(ast).await.unwrap();
        let mem = result.exec_state.stack();
        let sketch_value = mem
            .memory
            .get_from_owned("s", result.mem_env, SourceRange::default(), 0)
            .unwrap();

        let KclValue::Object { value, .. } = sketch_value else {
            panic!("Expected sketch block to return an object, got {sketch_value:?}");
        };

        assert!(value.contains_key("line1"));
        assert!(value.contains_key("line2"));
        // Ensure sketch2 aliases used during execution are not returned as
        // sketch block fields.
        assert!(!value.contains_key("line"));
        assert!(!value.contains_key("coincident"));
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn solver_module_is_not_available_outside_sketch_blocks() {
        let err = parse_execute("a = solver::ORIGIN").await.unwrap_err();
        assert!(err.message().contains("solver"), "Error message: '{}'", err.message());

        let err = parse_execute(
            r#"@settings(experimentalFeatures = allow)

import "std::solver""#,
        )
        .await
        .unwrap_err();
        assert!(
            err.message().contains("only available inside sketch blocks"),
            "Error message: '{}'",
            err.message()
        );
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn cannot_solid_extrude_an_open_profile() {
        // This should fail during mock execution, because KCL should catch
        // that the profile is not closed.
        let code = std::fs::read_to_string("tests/inputs/cannot_solid_extrude_an_open_profile.kcl").unwrap();
        let program = crate::Program::parse_no_errs(&code).expect("should parse");
        let exec_ctxt = ExecutorContext::new_mock(None).await;
        let mut exec_state = ExecState::new(&exec_ctxt);

        let err = exec_ctxt.run(&program, &mut exec_state).await.unwrap_err().error;
        assert!(matches!(err, KclError::Semantic { .. }));
        exec_ctxt.close().await;
    }
}