Enum regex_syntax::hir::HirKind

pub enum HirKind {
    Empty,
    Literal(Literal),
    Class(Class),
    Anchor(Anchor),
    WordBoundary(WordBoundary),
    Repetition(Repetition),
    Group(Group),
    Concat(Vec<Hir>),
    Alternation(Vec<Hir>),
}

The kind of an arbitrary Hir expression.

Variants

Empty

The empty regular expression, which matches everything, including the empty string.

Literal(Literal)

A single literal character that matches exactly this character.

Class(Class)

A single character class that matches any of the characters in the class. A class can either consist of Unicode scalar values as characters, or it can use bytes.

Anchor(Anchor)

An anchor assertion. An anchor assertion match always has zero length.

WordBoundary(WordBoundary)

A word boundary assertion, which may or may not be Unicode aware. A word boundary assertion match always has zero length.

Repetition(Repetition)

A repetition operation applied to a child expression.

Group(Group)

A possibly capturing group, which contains a child expression.

Concat(Vec<Hir>)

A concatenation of expressions. A concatenation always has at least two child expressions.

A concatenation matches only if each of its child expression matches one after the other.

Alternation(Vec<Hir>)

An alternation of expressions. An alternation always has at least two child expressions.

An alternation matches only if at least one of its child expression matches. If multiple expressions match, then the leftmost is preferred.

Implementations

impl HirKind

pub fn is_empty(&self) -> bool

Return true if and only if this HIR is the empty regular expression.

Note that this is not defined inductively. That is, it only tests if this kind is the Empty variant. To get the inductive definition, use the is_match_empty method on Hir.

pub fn has_subexprs(&self) -> bool

Returns true if and only if this kind has any (including possibly empty) subexpressions.

Trait Implementations

impl Clone for HirKind

fn clone(&self) -> HirKind

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for HirKind

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

Formats the value using the given formatter.

impl Eq for HirKind

impl PartialEq<HirKind> for HirKind

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl StructuralEq for HirKind

impl StructuralPartialEq for HirKind