Struct VariantShape 

pub struct VariantShape { /* private fields */ }

A kernel Shape that matches one specific ADT variant by tag and fields.

VariantShape accepts a TaggedValue whose ADT and variant match and whose fields each pass their PatternField shape, accumulating their captures. It also matches the equivalent constructor Expr, and reports subshape relationships against sibling variants and the enclosing AdtShape.

Implementations

impl VariantShape

pub fn new(adt: Symbol, variant: Symbol, fields: Vec<PatternField>) -> Self

Builds a variant shape from its ADT name, variant tag, and fields.

pub fn adt(&self) -> &Symbol

Returns the owning ADT name symbol.

pub fn variant(&self) -> &Symbol

Returns the variant tag symbol.

pub fn fields(&self) -> &[PatternField]

Returns the variant fields in declaration order.

Trait Implementations

impl Clone for VariantShape

fn clone(&self) -> VariantShape

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Shape for VariantShape

fn symbol(&self) -> Option<Symbol>

Symbol naming this shape when it has one, else None.

fn is_subshape_of( &self, cx: &mut Cx, parent: &dyn Shape, ) -> Result<Option<bool>>

Return a concrete implication answer when this shape owns the semantics.

fn check_value(&self, cx: &mut Cx, value: Value) -> Result<ShapeMatch>

Check a Value against this shape, yielding a ShapeMatch.

fn check_expr(&self, cx: &mut Cx, expr: &Expr) -> Result<ShapeMatch>

Check an Expr against this shape, yielding a ShapeMatch.

fn describe(&self, _cx: &mut Cx) -> Result<ShapeDoc>

Produce the human-facing ShapeDoc for this shape.

fn id(&self) -> Option<ShapeId>

Stable ShapeId when this shape has runtime identity, else None.

fn parents(&self, _cx: &mut Cx) -> Result<Vec<Value>, Error>

Parent shapes for the subshape walk; empty by default.

fn is_effectful(&self) -> bool

Whether matching this shape may run effects; false by default.

fn is_total(&self) -> bool

Whether this shape accepts every input in its domain; false by default.