Struct rustc_expand::mbe::diagnostics::CollectTrackerAndEmitter

struct CollectTrackerAndEmitter<'a, 'cx, 'matcher> {
    cx: &'a mut ExtCtxt<'cx>,
    remaining_matcher: Option<&'matcher MatcherLoc>,
    best_failure: Option<BestFailure>,
    root_span: Span,
    result: Option<Box<dyn MacResult + 'cx>>,
}

The tracker used for the slow error path that collects useful info for diagnostics.

Fields

cx: &'a mut ExtCtxt<'cx>

remaining_matcher: Option<&'matcher MatcherLoc>

best_failure: Option<BestFailure>

Which arm’s failure should we report? (the one furthest along)

root_span: Span

result: Option<Box<dyn MacResult + 'cx>>

Implementations

impl<'a, 'cx> CollectTrackerAndEmitter<'a, 'cx, '_>

fn new(cx: &'a mut ExtCtxt<'cx>, root_span: Span) -> Self

Trait Implementations

impl<'a, 'cx, 'matcher> Tracker<'matcher> for CollectTrackerAndEmitter<'a, 'cx, 'matcher>

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

The contents of ParseResult::Failure.

fn build_failure( tok: Token, position: usize, 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 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 description() -> &'static str

For tracing.

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: 128 bytes