HirKind in regex_syntax::hir - Rust (original) (raw)
pub enum HirKind {
Empty,
Literal(Literal),
Class(Class),
Look(Look),
Repetition(Repetition),
Capture(Capture),
Concat(Vec<Hir>),
Alternation(Vec<Hir>),
}Expand description
The underlying kind of an arbitrary Hir expression.
An HirKind is principally useful for doing case analysis on the type of a regular expression. If you’re looking to build new Hir values, then you must use the smart constructors defined on Hir, likeHir::repetition, to build new Hir values. The API intentionally does not expose any way of building an Hir directly from an HirKind.
The empty regular expression, which matches everything, including the empty string.
A literalstring that matches exactly these bytes.
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.
A class may be empty. In which case, it matches nothing.
A look-around assertion. A look-around match always has zero length.
A repetition operation applied to a sub-expression.
A capturing group, which contains a sub-expression.
A concatenation of expressions.
A concatenation matches only if each of its sub-expressions match one after the other.
Concatenations are guaranteed by Hir’s smart constructors to always have at least two sub-expressions.
An alternation of expressions.
An alternation matches only if at least one of its sub-expressions match. If multiple sub-expressions match, then the leftmost is preferred.
Alternations are guaranteed by Hir’s smart constructors to always have at least two sub-expressions.
Returns a slice of this kind’s sub-expressions, if any.
Tests for self and other values to be equal, and is used by ==.
Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.