Module matcher 

Matchers: grammar fragments used inside crate::parser::capture::Capture (via crate::capture) and related runners.

For users

• Matchers describe structure: sequences ((a, b)), crate::one_of::one_of, repetition (multiple::many, one_or_more(), optional()), lookahead (positive_lookahead(), negative_lookahead()), and commit_on() for committed sub-rules.
• They are composed with parsers through crate::capture; see crate::guide::capture_and_binds.
• Extend matchers with MatcherCombinator (with_label, try_insert_if_missing, unwanted, …).

Concept guides: crate::guide::core_concepts, crate::guide::errors_and_recovery, crate::guide::common_patterns.

Parameters and sealing

Matcher is parameterized by MRes, the “match result” type that captures bound values and spans (typically a tuple bucket produced by crate::parser::capture::Capture). You compose matchers rather than implementing Matcher yourself: it extends a crate-private implementation trait (not public API).

Associated constants

• CAN_FAIL — may return Ok(false) on a normal path (no match).
• HAS_PROPERTY — may write into MRes (captures).
• CAN_MATCH_DIRECTLY — optimization hint for the runner.

CAN_FAIL does not indicate whether Err with crate::error::MatcherRunError is possible.

Re-exports

pub use crate::error::MatcherRunError;

pub use any_token::AnyToken;

pub use commit_matcher::CommitMatcher;

pub use commit_matcher::commit_on;

pub use err_if::ErrIfMatchedMatcher;

pub use err_if::ErrIfNoMatchMatcher;

pub use err_if::err_if_matched;

pub use err_if::err_if_no_match;

pub use err_if::try_insert_if_missing;

pub use err_if::unwanted;

pub use error_contextualizer::ErrorContextualizer;

pub use multiple::Multiple;

pub use multiple::many;

pub use negative_lookahead::NegativeLookahead;

pub use negative_lookahead::negative_lookahead;

pub use one_or_more::OneOrMore;

pub use one_or_more::one_or_more;

pub use optional::Optional;

pub use optional::optional;

pub use parser_matcher::ParserMatcher;

pub use positive_lookahead::PositiveLookahead;

pub use positive_lookahead::positive_lookahead;

pub use string::StringMatcher;

pub use to_parser::ToParser;

Modules

any_token

Unconditional single-token consumption (if any input remains).

commit_matcher

Committing sequence: after commit_on succeeds, failure in then_matcher becomes a hard error.

err_if

Matchers that emit crate::error::InlineError when an inner pattern matches / does not match.

error_contextualizer

Enrich crate::error::FurthestFailError from happy_matcher using a small crate::parser::Parser callback.

if_error

Matchers and parsers that only participate while real error handling is active.

ignore_result

Parser-as-matcher adapters that discard parser output.

multiple

Zero-or-more repetition matcher; stops when matcher fails or makes no progress.

negative_lookahead

!e — succeeds when checker does not match at the current position (no input consumed).

none_of

Helpers for “match any token except …” patterns.

one_or_more

One-or-more repetition (matcher+).

optional

Optional matcher: tries matcher once; always reports success (whether or not it matched).

parser_matcher

Treat a crate::parser::Parser as a crate::matcher::Matcher: succeed only when parse output equals expected_output.

positive_lookahead

&e — succeeds when checker would match, without consuming input (position restored).

sequence

Sequential composition: tuples (m1, m2, …) implement crate::matcher::Matcher by running each arm in order.

string

Literal string / &str / char matchers over a char token stream.

to_parser

Matcher-to-parser adapters that return a fixed output.

Traits

Matcher

Facade for matchers over Token that read and write match state into MRes.

MatcherCombinator

Extension methods for matchers (labels, missing-token diagnostics, furthest-failure enrichment).