Struct FailureForwarder

pub(crate) struct FailureForwarder<'matcher> {
    expected_token: Option<&'matcher Token>,
}

Currently used by macro_rules! compilation to extract a little information from the Failure case.

Fields

expected_token: Option<&'matcher Token>

Implementations

impl<'matcher> FailureForwarder<'matcher>

pub(crate) fn new() -> Self

Trait Implementations

impl<'matcher> Tracker<'matcher> for FailureForwarder<'matcher>

type Failure = (Token, u32, &'static str)

The contents of ParseResult::Failure.

fn build_failure(tok: Token, position: u32, msg: &'static str) -> Self::Failure

Arm failed to match. If the token is token::Eof, it indicates an unexpected end of macro invocation. Otherwise, it indicates that no rules expected the given token. The usize is the approximate position of the token in the input token stream.

fn description() -> &'static str

For tracing.

fn set_expected_token(&mut self, tok: &'matcher Token)

fn get_expected_token(&self) -> Option<&'matcher Token>

fn before_match_loc( &mut self, _parser: &TtParser, _matcher: &'matcher MatcherLoc, )

This is called before trying to match next MatcherLoc on the current token.

fn after_arm( &mut self, _result: &ParseResult<FxHashMap<MacroRulesNormalizedIdent, NamedMatch>, Self::Failure>, )

This is called after an arm has been parsed, either successfully or unsuccessfully. When this is called, before_match_loc was called at least once (with a MatcherLoc::Eof).

fn recovery() -> Recovery

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 8 bytes