Struct LoweringDisposition 

pub struct LoweringDisposition {
    pub emits_items: bool,
    pub may_emit_boundary: bool,
    pub traverses_children: bool,
    pub records_side_facts: bool,
    pub is_intentional: bool,
    pub note: &'static str,
}

Multi-axis lowering disposition for a single AST NodeKind.

Each flag is independent; a node can simultaneously emit HIR items, emit dynamic-boundary markers, traverse children, and record side-facts.

The authoritative description of a node’s behavior is the lowerer source in hir/lower.rs; this registry mirrors that behavior and is validated by the hir-coverage xtask and the hir_lowering_completeness_tests.

Fields

emits_items: bool

The lowerer’s match arm calls push_item() to emit one or more non-boundary HIR items (e.g. PackageDecl, SubDecl, CallExpr).

may_emit_boundary: bool

The lowerer’s match arm may call push_item(DynamicBoundary(…)) — either unconditionally or on a runtime condition (e.g. Eval when block is not a block literal, Unary when symbolic-ref deref is detected).

traverses_children: bool

The lowerer traverses the node’s children (via visit_children or manual child iteration), allowing nested constructs to produce their own HIR items.

records_side_facts: bool

The lowerer records facts into side-graphs (scope bindings, stash slots, compile-environment directives, prototype table, …) without necessarily emitting a HIR item.

is_intentional: bool

true when the lowering disposition for this kind is intentionally decided — either because lower.rs has a named match arm, or because the node is deliberately traversal-only (e.g. ExpressionStatement) even if it falls to _ => visit_children as a simplification.

false means the node genuinely falls to _ => visit_children without a conscious design decision — i.e. it is “not yet modeled.”

Used by [legacy_category] to distinguish IntentionallySkipped from NotYetModeled.

note: &'static str

Human-readable note describing the lowering behavior. Used in the generated docs/project/status/hir_lowering.md and in test failure messages.

Implementations

impl LoweringDisposition

pub fn legacy_category(self) -> LegacyCategory

Derive the legacy four-category classification from the multi-axis flags.

This mapping is used by hir_coverage.rs to produce backward-compatible status-doc tables.

Derivation rules (in priority order):

1. emits_items → Lowered
2. !emits_items && may_emit_boundary → DynamicBoundary
3. !emits_items && !may_emit_boundary && is_intentional → IntentionallySkipped
4. !emits_items && !may_emit_boundary && !is_intentional → NotYetModeled

Trait Implementations

impl Clone for LoweringDisposition

fn clone(&self) -> LoweringDisposition

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LoweringDisposition

impl Debug for LoweringDisposition

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

Formats the value using the given formatter.

impl Eq for LoweringDisposition

impl PartialEq for LoweringDisposition

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for LoweringDisposition