Enum CspError 

pub enum CspError {
    Unsatisfiable,
    BudgetExceeded,
    InvalidInput {
        detail: String,
    },
    Timeout,
}

Unified error family for Csp/Sudoku/Futoshiki operations exposed across the PyO3 and wasm boundaries.

Deliberately flat (no nested Box<dyn Error> source chaining) — every downstream binding needs to pattern-match this by value to pick an exception class / HTTP status, and a flat enum is the cheapest thing that supports that without reflection.

Variants

Unsatisfiable

No solution exists under the current constraints/propagation. Maps from the crate’s existing crate::Unsatisfiable marker (kept as the internal propagation-layer type; this is the binding-facing supertype).

BudgetExceeded

The search aborted after crate::SolveConfig::node_budget nodes; any solutions returned are best-so-far, not verified optimal or exhaustive. Distinct from Unsatisfiable — conflating the two was Pass-1 finding R8/F12 (AssignmentBuilder and SudokuCSP both did this).

InvalidInput

A caller-supplied argument was structurally invalid: an out-of-range position, a malformed numeric key, an unknown enum value, mismatched dimensions, etc. Carries a human-readable detail string (never leaked Rust-internal panic/debug detail — callers construct this variant explicitly, it is never built from a caught panic).

Fields

detail: String

What was wrong, safe to surface to an API client verbatim.

Timeout

A wall-clock deadline elapsed before the search produced a result. Distinct from BudgetExceeded (a node-count budget, checked at the same cadence but triggered by count not time). Forward-declared for the wall-clock time_budget deferred item (synthesis-pass1 §3.1 N11) — the cooperative cancellation flag a caller’s own deadline should set through the CancelToken, so the abort reaches the search itself rather than only whatever coroutine or thread is awaiting it.

Implementations

impl CspError

pub const fn code(&self) -> &'static str

Stable machine-readable discriminant. This exact string is what py/errors.rs’s exception class names are derived from and what a wasm CspJsError.code carries across that boundary — the single vocabulary every layer of the taxonomy shares.

pub fn invalid_input(detail: impl Into<String>) -> Self

Convenience constructor — the one place format! call sites collapse into, instead of each binding hand-rolling its own PyValueError::new_err(format!(...)) / JsError::new(&format!(...)).

Trait Implementations

impl Clone for CspError

fn clone(&self) -> CspError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CspError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for CspError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for CspError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<AssignmentError> for CspError

AssignmentBuilder’s error family converts too, so py//wasm call sites that touch the assignment/COP path get the same typed exceptions as the Sudoku path for free. Note this conversion is itself evidence of Pass-1 finding R8: Infeasible collapses onto Unsatisfiable here because AssignmentError has no distinct budget-exhaustion variant yet — fixing that is a separate, already ledgered item, not silently patched over by this mapping.

fn from(e: AssignmentError) -> Self

Converts to this type from the input type.

impl From<Unsatisfiable> for CspError

The propagation layer’s existing marker type converts losslessly — every current ?-using call site (Csp::propagate, Csp::propagate_with) keeps compiling unchanged; only the bindings need to switch their map_err target.

fn from(_: Unsatisfiable) -> Self

Converts to this type from the input type.

impl PartialEq for CspError

fn eq(&self, other: &CspError) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for CspError