bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/mbe/src/tt_iter.rs')
-rw-r--r--crates/mbe/src/tt_iter.rs43
1 files changed, 42 insertions, 1 deletions
diff --git a/crates/mbe/src/tt_iter.rs b/crates/mbe/src/tt_iter.rs
index 7aceb676c7..a08eb2f554 100644
--- a/crates/mbe/src/tt_iter.rs
+++ b/crates/mbe/src/tt_iter.rs
@@ -1,6 +1,7 @@
//! A "Parser" structure for token trees. We use this when parsing a declarative
//! macro definition into a list of patterns and templates.
+use smallvec::{smallvec, SmallVec};
use syntax::SyntaxKind;
use tt::buffer::TokenBuffer;
@@ -80,13 +81,53 @@ impl<'a> TtIter<'a> {
}
}
- pub(crate) fn expect_punct(&mut self) -> Result<&'a tt::Punct, ()> {
+ pub(crate) fn expect_single_punct(&mut self) -> Result<&'a tt::Punct, ()> {
match self.expect_leaf()? {
tt::Leaf::Punct(it) => Ok(it),
_ => Err(()),
}
}
+ pub(crate) fn expect_glued_punct(&mut self) -> Result<SmallVec<[tt::Punct; 3]>, ()> {
+ let tt::TokenTree::Leaf(tt::Leaf::Punct(first)) = self.next().ok_or(())?.clone() else {
+ return Err(());
+ };
+
+ if first.spacing == tt::Spacing::Alone {
+ return Ok(smallvec![first]);
+ }
+
+ let (second, third) = match (self.peek_n(0), self.peek_n(1)) {
+ (
+ Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p2))),
+ Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p3))),
+ ) if p2.spacing == tt::Spacing::Joint => (p2, Some(p3)),
+ (Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p2))), _) => (p2, None),
+ _ => return Ok(smallvec![first]),
+ };
+
+ match (first.char, second.char, third.map(|it| it.char)) {
+ ('.', '.', Some('.' | '=')) | ('<', '<', Some('=')) | ('>', '>', Some('=')) => {
+ let puncts = smallvec![first, second.clone(), third.unwrap().clone()];
+ let _ = self.next().unwrap();
+ let _ = self.next().unwrap();
+ Ok(puncts)
+ }
+ ('-' | '!' | '*' | '/' | '&' | '%' | '^' | '+' | '<' | '=' | '>' | '|', '=', _)
+ | ('-' | '=' | '>', '>', _)
+ | (':', ':', _)
+ | ('.', '.', _)
+ | ('&', '&', _)
+ | ('<', '<', _)
+ | ('|', '|', _) => {
+ let puncts = smallvec![first, second.clone()];
+ let _ = self.next().unwrap();
+ Ok(puncts)
+ }
+ _ => Ok(smallvec![first]),
+ }
+ }
+
pub(crate) fn expect_fragment(
&mut self,
entry_point: parser::PrefixEntryPoint,