Enum rustc_expand::mbe::TokenTree

enum TokenTree {
    Token(Token),
    Delimited(DelimSpan, Lrc<Delimited>),
    Sequence(DelimSpan, Lrc<SequenceRepetition>),
    MetaVar(Span, Ident),
    MetaVarDecl(Span, Ident, Option<NonterminalKind>),
}

Similar to tokenstream::TokenTree, except that $i, $i:ident, and $(...) are “first-class” token trees. Useful for parsing macros.

Variants

Token(Token)

Tuple Fields of Token

0: Token

Delimited(DelimSpan, Lrc<Delimited>)

Tuple Fields of Delimited

0: DelimSpan1: Lrc<Delimited>

Sequence(DelimSpan, Lrc<SequenceRepetition>)

A kleene-style repetition sequence

Tuple Fields of Sequence

0: DelimSpan1: Lrc<SequenceRepetition>

MetaVar(Span, Ident)

e.g., $var

Tuple Fields of MetaVar

0: Span1: Ident

MetaVarDecl(Span, Ident, Option<NonterminalKind>)

e.g., $var:expr. This is only used in the left hand side of MBE macros.

Tuple Fields of MetaVarDecl

0: Span1: Ident2: Option<NonterminalKind>

Implementations

impl TokenTree

fn len(&self) -> usize

Return the number of tokens in the tree.

fn is_delimited(&self) -> bool

Returns true if the given token tree is delimited.

fn is_token(&self, expected_kind: &TokenKind) -> bool

Returns true if the given token tree is a token of the given kind.

fn get_tt(&self, index: usize) -> TokenTree

Gets the index-th sub-token-tree. This only makes sense for delimited trees and sequences.

fn span(&self) -> Span

Retrieves the TokenTree’s span.

fn token(kind: TokenKind, span: Span) -> TokenTree

Trait Implementations

impl Clone for TokenTree

fn clone(&self) -> TokenTree

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for TokenTree

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

Formats the value using the given formatter.

impl<__D: Decoder> Decodable<__D> for TokenTree

fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

impl<__E: Encoder> Encodable<__E> for TokenTree

fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

impl PartialEq<TokenTree> for TokenTree

fn eq(&self, other: &TokenTree) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &TokenTree) -> bool

This method tests for !=.

impl StructuralPartialEq for TokenTree

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: 32 bytes

Size for each variant:

• Token: 31 bytes
• Delimited: 31 bytes
• Sequence: 31 bytes
• MetaVar: 23 bytes
• MetaVarDecl: 23 bytes