Enum libslide::evaluator_rules::rule::Rule

pub enum Rule {
    PatternMap(PatternMap),
    Evaluate(fn(_: RcExpr) -> Option<RcExpr>),
}

Variants

PatternMap(PatternMap)

Evaluate(fn(_: RcExpr) -> Option<RcExpr>)

Implementations

impl Rule

pub fn from_fn(f: fn(_: RcExpr) -> Option<RcExpr>) -> Self

pub fn from_str(s: &str) -> Self

Trait Implementations

impl Debug for Rule

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

Formats the value using the given formatter.

impl Display for Rule

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

Formats the value using the given formatter.

impl Transformer<RcExpr, RcExpr> for Rule

fn transform(&self, target: RcExpr) -> RcExpr

Attempts to apply a rule on a target expression by

1. Applying the rule recursively on the target's subexpression to obtain a partially-transformed target expression.

2. Pattern matching the lhs of the rule with the partially-transformed target expression.

• If pattern matching is unsuccessful, no application is done and the original expression is returned.

3. Expanding the rhs of the rule using the results of the pattern matching.

Examples:

"$x + 0 -> $x".try_apply("x + 0")  // Some(x)
"$x + 0 -> $x".try_apply("x + 1")  // None
"$x + 0 -> $x".try_apply("x")      // None

impl Transformer<RcExprPat, RcExprPat> for Rule

fn transform(&self, target: RcExprPat) -> RcExprPat

Bootstraps a rule with another (or possibly the same) rule.