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,
}
Expand description

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

§num_metavar_decls: usize
§idx_first_after: usize
§next_metavar: usize
§seq_depth: usize
§

SequenceKleeneOpNoSep

Fields

§idx_first: usize
§

SequenceSep

Fields

§separator: Token
§

SequenceKleeneOpAfterSep

Fields

§idx_first: usize
§

MetaVarDecl

Fields

§span: Span
§bind: Ident
§next_metavar: usize
§seq_depth: usize
§

Eof

Implementations§

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Formats the value using the given formatter. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
Converts the given value to a String. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.

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