Struct Expr 

pub struct Expr { /* private fields */ }

A parsed, ready-to-evaluate condition expression.

Produced by parse and evaluated by Expr::eval. It owns its whole AST, borrows nothing, and holds no IO, clock, or randomness, so it is safe to keep and re-evaluate for the life of a run.

Implementations

impl Expr

pub fn eval(&self, value: &Value) -> bool

Evaluates the expression against a routed value, always returning a bool.

This is TOTAL: it never panics and never errors for any value. The missing-path, type-mismatch, and number-comparison semantics are those documented on the module. Eval is a single linear walk of the AST, whose size is bounded by MAX_EXPRESSION_LEN.

pub fn paths(&self) -> Vec<&[Segment]>

Every path this expression reads, in the order the source names them, as borrowed segment slices.

Literal operands are not paths and do not appear. A path repeated in the source appears once per mention, because this reports what the expression READS rather than a de-duplicated set of locations.

Exported for the same reason compare is: a second consumer needs the expression’s own answer rather than one re-derived beside it. The graph validator checks a fold’s stop_when against the declared shape of the value it will read, and the only honest source for “which locations does this predicate read” is the parse that already found them. Eval is untouched: this walks the same AST and changes nothing about it.

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Expr

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

Formats the value using the given formatter.

impl PartialEq for Expr

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Expr