[][src]Enum syntax::ext::tt::quoted::TokenTree

pub enum TokenTree {
    Token(SpanToken),
    Delimited(DelimSpanLrc<Delimited>),
    Sequence(DelimSpanLrc<SequenceRepetition>),
    MetaVar(SpanIdent),
    MetaVarDecl(SpanIdentIdent),
}

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

Variants

Token(SpanToken)Delimited(DelimSpanLrc<Delimited>)Sequence(DelimSpanLrc<SequenceRepetition>)

A kleene-style repetition sequence

MetaVar(SpanIdent)

e.g., $var

MetaVarDecl(SpanIdentIdent)

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

Methods

impl TokenTree[src]

pub fn len(&self) -> usize[src]

Return the number of tokens in the tree.

pub fn is_empty(&self) -> bool[src]

Returns true if the given token tree contains no other tokens. This is vacuously true for single tokens or metavar/decls, but may be false for delimited trees or sequences.

pub fn get_tt(&self, index: usize) -> TokenTree[src]

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

pub fn span(&self) -> Span[src]

Retrieves the TokenTree's span.

Trait Implementations

impl Clone for TokenTree[src]

fn clone_from(&mut self, source: &Self)1.0.0[src]

Performs copy-assignment from source. Read more

impl PartialEq<TokenTree> for TokenTree[src]

impl Debug for TokenTree[src]

impl Encodable for TokenTree[src]

impl Decodable for TokenTree[src]

Auto Trait Implementations

impl !Send for TokenTree

impl !Sync for TokenTree

Blanket Implementations

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Encodable for T where
    T: UseSpecializedEncodable + ?Sized
[src]

impl<T> Decodable for T where
    T: UseSpecializedDecodable
[src]

impl<E> SpecializationError for E[src]

impl<T> Send for T where
    T: ?Sized
[src]

impl<T> Sync for T where
    T: ?Sized
[src]

impl<T> Erased for T[src]