Struct libslide::evaluator_rules::rule::PatternMap

pub struct PatternMap {
    pub from: RcExprPat,
    pub to: RcExprPat,
}

A mapping between two expression patterns.

Fields

from: RcExprPat

to: RcExprPat

Implementations

impl PatternMap

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

Converts a string representation of a rule to a PatternMap. A rule's string form must be

"<expr> -> <expr>"

Where <expr> is an expression pattern.

pub fn bootstrap(&self, bootstrapping_rules: &[Rule]) -> Self

Bootstraps a PatternMap rule with a one-pass application of a rule set, which may include the rule itself.

This allows the rule to match evaluated contexts that cannot be represented by a PatternMap created from just a string form. For example, the rule

"-(_a - _b) -> _b - _a"

in its raw form may only be applied to an expression with explicit parentheses. By bootstrapping this rule with a rule that removes explicit parentheses, the rule can be applied on expressions with implicit parentheses (i.e. of the prefix form (- (- _a _b))).

pub fn validate(&self) -> Result<(), UnresolvedMapping>

Checks a PatternMap is resolvable, returning an error if it is not.

Trait Implementations

impl Clone for PatternMap

fn clone(&self) -> PatternMap

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for PatternMap

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

Formats the value using the given formatter.

impl Display for PatternMap

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

Formats the value using the given formatter.