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use super::ToTokens;
use std::iter;
use proc_macro2::{TokenStream, TokenTree};
pub trait TokenStreamExt: private::Sealed {
fn append<U>(&mut self, token: U)
where
U: Into<TokenTree>;
fn append_all<I>(&mut self, iter: I)
where
I: IntoIterator,
I::Item: ToTokens;
fn append_separated<I, U>(&mut self, iter: I, op: U)
where
I: IntoIterator,
I::Item: ToTokens,
U: ToTokens;
fn append_terminated<I, U>(&mut self, iter: I, term: U)
where
I: IntoIterator,
I::Item: ToTokens,
U: ToTokens;
}
impl TokenStreamExt for TokenStream {
fn append<U>(&mut self, token: U)
where
U: Into<TokenTree>,
{
self.extend(iter::once(token.into()));
}
fn append_all<I>(&mut self, iter: I)
where
I: IntoIterator,
I::Item: ToTokens,
{
for token in iter {
token.to_tokens(self);
}
}
fn append_separated<I, U>(&mut self, iter: I, op: U)
where
I: IntoIterator,
I::Item: ToTokens,
U: ToTokens,
{
for (i, token) in iter.into_iter().enumerate() {
if i > 0 {
op.to_tokens(self);
}
token.to_tokens(self);
}
}
fn append_terminated<I, U>(&mut self, iter: I, term: U)
where
I: IntoIterator,
I::Item: ToTokens,
U: ToTokens,
{
for token in iter {
token.to_tokens(self);
term.to_tokens(self);
}
}
}
mod private {
use proc_macro2::TokenStream;
pub trait Sealed {}
impl Sealed for TokenStream {}
}