Struct pmutil::prelude::TokenStream

pub struct TokenStream { /* fields omitted */ }

An abstract stream of tokens, or more concretely a sequence of token trees.

This type provides interfaces for iterating over token trees and for collecting token trees into one stream.

Token stream 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 empty() -> TokenStream

Deprecated since 0.4.4

: please use TokenStream::new

pub fn is_empty(&self) -> bool

Checks if this TokenStream is empty.

Trait Implementations

impl Extend<TokenTree> for TokenStream

fn extend<I>(&mut self, streams: I) where     I: IntoIterator<Item = TokenTree>,

Extends a collection with the contents of an iterator.

impl FromIterator<TokenTree> for TokenStream

Collects a number of token trees into a single stream.

fn from_iter<I>(streams: I) -> TokenStream where     I: IntoIterator<Item = TokenTree>,

Creates a value from an iterator.

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.

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

Formats the value using the given formatter.

impl Clone for TokenStream

fn clone(&self) -> TokenStream

Returns a copy of the value.

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

Performs copy-assignment from source.

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.

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

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.

impl Debug for TokenStream

Prints token in a form convenient for debugging.

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

Formats the value using the given formatter.

impl IntoIterator for TokenStream

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 From<TokenStream> for TokenStream

fn from(inner: TokenStream) -> TokenStream

Performs the conversion.

impl From<TokenStream> for TokenStream

fn from(inner: TokenStream) -> TokenStream

Performs the conversion.

impl TokenStreamExt for TokenStream

fn append<U>(&mut self, token: U) where     U: Into<TokenTree>,

For use by ToTokens implementations.

Appends the token specified to this list of tokens.

fn append_all<T, I>(&mut self, iter: I) where     I: IntoIterator<Item = T>,     T: ToTokens,

For use by ToTokens implementations.

struct X;

impl ToTokens for X {
    fn to_tokens(&self, tokens: &mut TokenStream) {
        tokens.append_all(&[true, false]);
    }
}

let tokens = quote!(#X);
assert_eq!(tokens.to_string(), "true false");

fn append_separated<T, I, U>(&mut self, iter: I, op: U) where     I: IntoIterator<Item = T>,     T: ToTokens,     U: ToTokens,

For use by ToTokens implementations.

Appends all of the items in the iterator I, separated by the tokens U.

fn append_terminated<T, I, U>(&mut self, iter: I, term: U) where     I: IntoIterator<Item = T>,     T: ToTokens,     U: ToTokens,

For use by ToTokens implementations.

Appends all tokens in the iterator I, appending U after each element, including after the last element of the iterator.

impl ToTokens for TokenStream

fn to_tokens(&self, dst: &mut TokenStream)

Write self to the given TokenStream.

fn into_token_stream(self) -> TokenStream

Convert self directly into a TokenStream object.

impl Synom for TokenStream

fn parse(input: Cursor) -> Result<(TokenStream, Cursor), ParseError>

fn description() -> Option<&'static str>

A short name of the type being parsed.

impl From<Quote> for TokenStream

fn from(quote: Quote) -> Self

Performs the conversion.