Struct regex_syntax::ast::parse::Parser

pub struct Parser {
    pos: Cell<Position>,
    capture_index: Cell<u32>,
    nest_limit: u32,
    octal: bool,
    initial_ignore_whitespace: bool,
    empty_min_range: bool,
    ignore_whitespace: Cell<bool>,
    comments: RefCell<Vec<Comment>>,
    stack_group: RefCell<Vec<GroupState>>,
    stack_class: RefCell<Vec<ClassState>>,
    capture_names: RefCell<Vec<CaptureName>>,
    scratch: RefCell<String>,
}

A regular expression parser.

This parses a string representation of a regular expression into an abstract syntax tree. The size of the tree is proportional to the length of the regular expression pattern.

A Parser can be configured in more detail via a ParserBuilder.

Fields

pos: Cell<Position>

The current position of the parser.

capture_index: Cell<u32>

The current capture index.

nest_limit: u32

The maximum number of open parens/brackets allowed. If the parser exceeds this number, then an error is returned.

octal: bool

Whether to support octal syntax or not. When false, the parser will return an error helpfully pointing out that backreferences are not supported.

initial_ignore_whitespace: bool

The initial setting for ignore_whitespace as provided by ParserBuilder. It is used when resetting the parser’s state.

empty_min_range: bool

Whether the parser supports {,n} repetitions as an equivalent to {0,n}.

ignore_whitespace: Cell<bool>

Whether whitespace should be ignored. When enabled, comments are also permitted.

comments: RefCell<Vec<Comment>>

A list of comments, in order of appearance.

stack_group: RefCell<Vec<GroupState>>

A stack of grouped sub-expressions, including alternations.

stack_class: RefCell<Vec<ClassState>>

A stack of nested character classes. This is only non-empty when parsing a class.

capture_names: RefCell<Vec<CaptureName>>

A sorted sequence of capture names. This is used to detect duplicate capture names and report an error if one is detected.

scratch: RefCell<String>

A scratch buffer used in various places. Mostly this is used to accumulate relevant characters from parts of a pattern.

Implementations

impl Parser

pub fn new() -> Parser

Create a new parser with a default configuration.

The parser can be run with either the parse or parse_with_comments methods. The parse methods return an abstract syntax tree.

To set configuration options on the parser, use ParserBuilder.

pub fn parse(&mut self, pattern: &str) -> Result<Ast, Error>

Parse the regular expression into an abstract syntax tree.

pub fn parse_with_comments( &mut self, pattern: &str, ) -> Result<WithComments, Error>

Parse the regular expression and return an abstract syntax tree with all of the comments found in the pattern.

fn reset(&self)

Reset the internal state of a parser.

This is called at the beginning of every parse. This prevents the parser from running with inconsistent state (say, if a previous invocation returned an error and the parser is reused).

Trait Implementations

impl Clone for Parser

fn clone(&self) -> Parser

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Parser

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

Formats the value using the given formatter.