Enum regex_syntax::ast::Ast

pub enum Ast {
    Empty(Span),
    Flags(SetFlags),
    Literal(Literal),
    Dot(Span),
    Assertion(Assertion),
    Class(Class),
    Repetition(Repetition),
    Group(Group),
    Alternation(Alternation),
    Concat(Concat),
}

An abstract syntax tree for a single regular expression.

An Ast’s fmt::Display implementation uses constant stack space and heap space proportional to the size of the Ast.

This type defines its own destructor that uses constant stack space and heap space proportional to the size of the Ast.

Variants

Empty(Span)

An empty regex that matches everything.

Flags(SetFlags)

A set of flags, e.g., (?is).

Literal(Literal)

A single character literal, which includes escape sequences.

Dot(Span)

The “any character” class.

Assertion(Assertion)

A single zero-width assertion.

Class(Class)

A single character class. This includes all forms of character classes except for .. e.g., \d, \pN, [a-z] and [[:alpha:]].

Repetition(Repetition)

A repetition operator applied to an arbitrary regular expression.

Group(Group)

A grouped regular expression.

Alternation(Alternation)

An alternation of regular expressions.

Concat(Concat)

A concatenation of regular expressions.

Implementations

impl Ast

pub fn span(&self) -> &Span

Return the span of this abstract syntax tree.

pub fn is_empty(&self) -> bool

Return true if and only if this Ast is empty.

Trait Implementations

impl Clone for Ast

fn clone(&self) -> Ast

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Ast

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

Formats the value using the given formatter.

impl Display for Ast

Print a display representation of this Ast.

This does not preserve any of the original whitespace formatting that may have originally been present in the concrete syntax from which this Ast was generated.

This implementation uses constant stack space and heap space proportional to the size of the Ast.

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

Formats the value using the given formatter.

impl Drop for Ast

A custom Drop impl is used for Ast such that it uses constant stack space but heap space proportional to the depth of the Ast.

fn drop(&mut self)

Executes the destructor for this type.

impl PartialEq for Ast

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

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

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

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

impl Eq for Ast

impl StructuralPartialEq for Ast