Enum rustc_expand::mbe::macro_parser::MatcherLoc

pub(crate) enum MatcherLoc {
    Token {
        token: Token,
    },
    Delimited,
    Sequence {
        op: KleeneOp,
        num_metavar_decls: usize,
        idx_first_after: usize,
        next_metavar: usize,
        seq_depth: usize,
    },
    SequenceKleeneOpNoSep {
        op: KleeneOp,
        idx_first: usize,
    },
    SequenceSep {
        separator: Token,
    },
    SequenceKleeneOpAfterSep {
        idx_first: usize,
    },
    MetaVarDecl {
        span: Span,
        bind: Ident,
        kind: Option<NonterminalKind>,
        next_metavar: usize,
        seq_depth: usize,
    },
    Eof,
}

A unit within a matcher that a MatcherPos can refer to. Similar to (and derived from) mbe::TokenTree, but designed specifically for fast and easy traversal during matching. Notable differences to mbe::TokenTree:

• It is non-recursive, i.e. there is no nesting.
• The end pieces of each sequence (the separator, if present, and the Kleene op) are represented explicitly, as is the very end of the matcher.

This means a matcher can be represented by &[MatcherLoc], and traversal mostly involves simply incrementing the current matcher position index by one.

Variants

Token

Fields

token: Token

Delimited

Sequence

Fields

op: KleeneOp

num_metavar_decls: usize

idx_first_after: usize

next_metavar: usize

seq_depth: usize

SequenceKleeneOpNoSep

Fields

op: KleeneOp

idx_first: usize

SequenceSep

Fields

separator: Token

SequenceKleeneOpAfterSep

Fields

idx_first: usize

MetaVarDecl

Fields

span: Span

bind: Ident

kind: Option<NonterminalKind>

next_metavar: usize

seq_depth: usize

Eof

Implementations

impl MatcherLoc

pub(super) fn span(&self) -> Option<Span>

Trait Implementations

impl Clone for MatcherLoc

fn clone(&self) -> MatcherLoc

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MatcherLoc

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

Formats the value using the given formatter.

impl Display for MatcherLoc

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

Formats the value using the given formatter.

impl PartialEq for MatcherLoc

fn eq(&self, other: &MatcherLoc) -> 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 StructuralPartialEq for MatcherLoc

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: 40 bytes

Size for each variant:

• Token: 31 bytes
• Delimited: 0 bytes
• Sequence: 39 bytes
• SequenceKleeneOpNoSep: 15 bytes
• SequenceSep: 31 bytes
• SequenceKleeneOpAfterSep: 15 bytes
• MetaVarDecl: 39 bytes
• Eof: 0 bytes