Struct PrattShape 

pub struct PrattShape { /* private fields */ }

A shape that parses a string expression with a ShapeExprParser before matching.

Accepts only String expressions: the text is parsed and the resulting expression is checked against the inner shape. Non-string inputs and parse failures reject.

Implementations

impl PrattShape

pub fn new(parser: Arc<dyn ShapeExprParser>, inner: Arc<dyn Shape>) -> Self

Build a shape that parses string input with parser, then checks inner.

pub fn parser(&self) -> &Arc<dyn ShapeExprParser>

The parser applied to string input.

pub fn inner(&self) -> &Arc<dyn Shape>

The inner shape checked against the parsed expression.

Trait Implementations

impl Shape for PrattShape

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 symbol(&self) -> Option<Symbol>

Symbol naming this shape when it has one, 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.

fn is_subshape_of( &self, _cx: &mut Cx, _parent: &dyn Shape, ) -> Result<Option<bool>, Error>

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