Enum proc_macro::TokenTree

pub enum TokenTree {
    Group(Group),
    Ident(Ident),
    Punct(Punct),
    Literal(Literal),
}

🔬 This is a nightly-only experimental API. (proc_macro #38356)

A single token or a delimited sequence of token trees (e.g. [1, (), ..]).

Variants

Group(Group)

🔬 This is a nightly-only experimental API. (proc_macro #38356)

A token stream surrounded by bracket delimiters.

Ident(Ident)

🔬 This is a nightly-only experimental API. (proc_macro #38356)

An identifier.

Punct(Punct)

🔬 This is a nightly-only experimental API. (proc_macro #38356)

A single punctuation character (+, ,, $, etc.).

Literal(Literal)

🔬 This is a nightly-only experimental API. (proc_macro #38356)

A literal character ('a'), string ("hello"), number (2.3), etc.

Methods

impl TokenTree

pub fn span(&self) -> Span

🔬 This is a nightly-only experimental API. (proc_macro #38356)

Returns the span of this tree, delegating to the span method of the contained token or a delimited stream.

pub fn set_span(&mut self, span: Span)

🔬 This is a nightly-only experimental API. (proc_macro #38356)

Configures the span for only this token.

Note that if this token is a Group then this method will not configure the span of each of the internal tokens, this will simply delegate to the set_span method of each variant.

Trait Implementations

impl From<TokenTree> for TokenStream

Creates a token stream containing a single token tree.

fn from(tree: TokenTree) -> TokenStream

Performs the conversion.

impl FromIterator<TokenTree> for TokenStream

Collects a number of token trees into a single stream.

fn from_iter<I: IntoIterator<Item = TokenTree>>(trees: I) -> Self

Creates a value from an iterator.

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 !Send for TokenTree

impl !Sync for TokenTree

impl Debug for TokenTree

Prints token treee in a form convenient for debugging.

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

Formats the value using the given formatter.

impl From<Group> for TokenTree

fn from(g: Group) -> TokenTree

Performs the conversion.

impl From<Ident> for TokenTree

fn from(g: Ident) -> TokenTree

Performs the conversion.

impl From<Punct> for TokenTree

fn from(g: Punct) -> TokenTree

Performs the conversion.

impl From<Literal> for TokenTree

fn from(g: Literal) -> TokenTree

Performs the conversion.

impl Display for TokenTree

Prints the token tree as a string that is supposed to be losslessly convertible back into the same token tree (modulo spans), except for possibly TokenTree::Groups with Delimiter::None delimiters and negative numeric literals.

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

Formats the value using the given formatter.