Struct proc_macro::TokenStream

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pub struct TokenStream(_);

[−] Expand description

The main type provided by this crate, representing an abstract stream of tokens, or, more specifically, a sequence of token trees. The type provide interfaces for iterating over those token trees and, conversely, collecting a number of token trees into one stream.

This is both the input and output of #[proc_macro], #[proc_macro_attribute] and #[proc_macro_derive] definitions.

Methods

impl TokenStream[−]

pub fn new() -> TokenStream[−]

Returns an empty TokenStream containing no token trees.

pub fn is_empty(&self) -> bool[−]

Checks if this TokenStream is empty.

Trait Implementations

impl !Sync for TokenStream

impl ToString for TokenStream[+]

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fn to_string(&self) -> String[−]

Converts the given value to a String.

impl IntoIterator for TokenStream[+]

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type Item = TokenTree

The type of the elements being iterated over.

type IntoIter = IntoIter

Which kind of iterator are we turning this into?

Important traits for IntoIter

impl Iterator for IntoIter type Item = TokenTree;

fn into_iter(self) -> IntoIter[−]

Creates an iterator from a value.

impl Clone for TokenStream[+]

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fn clone(&self) -> TokenStream[−]

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Extend<TokenTree> for TokenStream[+]

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fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, trees: I)[−]

Extends a collection with the contents of an iterator.

impl Extend<TokenStream> for TokenStream[+]

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fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I)[−]

Extends a collection with the contents of an iterator.

impl !Send for TokenStream

impl From<TokenTree> for TokenStream[+]

Creates a token stream containing a single token tree.

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fn from(tree: TokenTree) -> TokenStream[−]

Performs the conversion.

impl Display for TokenStream[+]

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

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

Formats the value using the given formatter.

impl FromIterator<TokenTree> for TokenStream[+]

Collects a number of token trees into a single stream.

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

Creates a value from an iterator.

impl FromIterator<TokenStream> for TokenStream[+]

A "flattening" operation on token streams, collects token trees from multiple token streams into a single stream.

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fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self[−]

Creates a value from an iterator.

impl Debug for TokenStream[+]

Prints token in a form convenient for debugging.

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

Formats the value using the given formatter.

impl FromStr for TokenStream[+]

Attempts to break the string into tokens and parse those tokens into a token stream. May fail for a number of reasons, for example, if the string contains unbalanced delimiters or characters not existing in the language. All tokens in the parsed stream get Span::call_site() spans.

NOTE: some errors may cause panics instead of returning LexError. We reserve the right to change these errors into LexErrors later.

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type Err = LexError

The associated error which can be returned from parsing.

fn from_str(src: &str) -> Result<TokenStream, LexError>[−]

Parses a string s to return a value of this type.