Struct Rule 

pub struct Rule<'a> {
    pub name: &'a str,
    pub application: fn(&Expression, &SymbolTable) -> Result<Reduction, ApplicationError>,
    pub rule_sets: &'a [(&'a str, u16)],
}

A rule with a name, application function, and rule sets.

Fields

• name The name of the rule.
• application The function to apply the rule.
• rule_sets A list of rule set names and priorities that this rule is a part of. This is used to populate rulesets at runtime.

Fields

name: &'a str

application: fn(&Expression, &SymbolTable) -> Result<Reduction, ApplicationError>

rule_sets: &'a [(&'a str, u16)]

Implementations

impl<'a> Rule<'a>

pub const fn new( name: &'a str, application: fn(&Expression, &SymbolTable) -> Result<Reduction, ApplicationError>, rule_sets: &'a [(&'static str, u16)], ) -> Rule<'a>

pub fn apply( &self, expr: &Expression, symbols: &SymbolTable, ) -> Result<Reduction, ApplicationError>

Trait Implementations

impl<'a> Clone for Rule<'a>

fn clone(&self) -> Rule<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for Rule<'a>

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

Formats the value using the given formatter.

impl Display for Rule<'_>

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

Formats the value using the given formatter.

impl Hash for Rule<'_>

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Rule<'_>

fn eq(&self, other: &Rule<'_>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Rule<Expression, SymbolTable> for &Rule<'_>

fn apply( &self, commands: &mut Commands<Expression, SymbolTable>, subtree: &Expression, meta: &SymbolTable, ) -> Option<Expression>

Applies the rule to the given subtree and returns the result if applicable.

impl Rule<Expression, SymbolTable> for Rule<'_>

fn apply( &self, commands: &mut Commands<Expression, SymbolTable>, subtree: &Expression, meta: &SymbolTable, ) -> Option<Expression>

Applies the rule to the given subtree and returns the result if applicable.

impl Eq for Rule<'_>

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 40 bytes