Enum regex_syntax::hir::HirKind[−][src]

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

Expand description

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.

Tuple Fields of Literal

0: Literal

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.

Tuple Fields of Class

0: Class

Anchor(Anchor)

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

Tuple Fields of Anchor

0: Anchor

WordBoundary(WordBoundary)

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

Tuple Fields of WordBoundary

0: WordBoundary

Repetition(Repetition)

A repetition operation applied to a child expression.

Tuple Fields of Repetition

0: Repetition

Group(Group)

A possibly capturing group, which contains a child expression.

Tuple Fields of Group

0: Group

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.

Tuple Fields of Concat

0: Vec<Hir>

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.

Tuple Fields of Alternation

0: Vec<Hir>

Implementations

[src]

impl HirKind

[src]

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.

[src]