Add fast path when None delimiters are not involved

This commit is contained in:
Aaron Hill 2021-04-12 17:26:26 -04:00
parent eb7b1a150f
commit c6d67f8317
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@ -929,6 +929,25 @@ impl<'a> Parser<'a> {
return looker(&self.token);
}
let frame = &self.token_cursor.frame;
if frame.delim != DelimToken::NoDelim {
let all_normal = (0..dist).all(|i| {
let token = frame.tree_cursor.look_ahead(i);
!matches!(token, Some(TokenTree::Delimited(_, DelimToken::NoDelim, _)))
});
if all_normal {
return match frame.tree_cursor.look_ahead(dist - 1) {
Some(tree) => match tree {
TokenTree::Token(token) => looker(token),
TokenTree::Delimited(dspan, delim, _) => {
looker(&Token::new(token::OpenDelim(*delim), dspan.open))
}
},
None => looker(&Token::new(token::CloseDelim(frame.delim), frame.span.close)),
};
}
}
let mut cursor = self.token_cursor.clone();
let mut i = 0;
let mut token = Token::dummy();