bjoernager/rust
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Merge TokenCursor::{next,next_desugared}.

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And likewise for the inlined variants.

I did this for simplicity, but interesting it was a performance win as
well.
This commit is contained in:
Nicholas Nethercote 2022-04-19 11:36:13 +10:00
parent 89ec75b0e9
commit b1e6dee596
2 changed files with 72 additions and 86 deletions
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17
compiler/rustc_parse/src/parser/attr_wrapper.rs
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@ -100,21 +100,16 @@ rustc_data_structures::static_assert_size!(LazyTokenStreamImpl, 144);
impl CreateTokenStream for LazyTokenStreamImpl {
fn create_token_stream(&self) -> AttrAnnotatedTokenStream {
// The token produced by the final call to `{,inlined_}next` or
// `{,inlined_}next_desugared` was not actually consumed by the
// callback. The combination of chaining the initial token and using
// `take` produces the desired result - we produce an empty
// `TokenStream` if no calls were made, and omit the final token
// otherwise.
// The token produced by the final call to `{,inlined_}next` was not
// actually consumed by the callback. The combination of chaining the
// initial token and using `take` produces the desired result - we
// produce an empty `TokenStream` if no calls were made, and omit the
// final token otherwise.
let mut cursor_snapshot = self.cursor_snapshot.clone();
let tokens =
std::iter::once((FlatToken::Token(self.start_token.0.clone()), self.start_token.1))
.chain((0..self.num_calls).map(|_| {
let token = if cursor_snapshot.desugar_doc_comments {
cursor_snapshot.next_desugared()
} else {
cursor_snapshot.next()
};
let token = cursor_snapshot.next(cursor_snapshot.desugar_doc_comments);
(FlatToken::Token(token.0), token.1)
}))
.take(self.num_calls);