Enum rustc_expand::mbe::TokenTree

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

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

Variants

Token(Token)

Delimited(DelimSpan, Lrc<Delimited>)

Sequence(DelimSpan, Lrc<SequenceRepetition>)

A kleene-style repetition sequence

MetaVar(Span, Ident)

e.g., $var

MetaVarDecl(Span, Ident, NonterminalKind)

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

Implementations

impl TokenTree

pub(in mbe) fn len(
    &self
) -> usize

Return the number of tokens in the tree.

pub(in mbe) fn is_delimited(
    &self
) -> bool

Returns true if the given token tree is delimited.

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

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

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

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

pub(in mbe) fn span(
    &self
) -> Span

Retrieves the TokenTree's span.

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

Trait Implementations

impl Clone for TokenTree

pub fn clone(&self) -> TokenTree

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for TokenTree

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

Formats the value using the given formatter.

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

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

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

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

impl PartialEq<TokenTree> for TokenTree

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

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

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

This method tests for !=.

impl StructuralPartialEq for TokenTree