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Extract multi-character punct handling into a method
| -rw-r--r-- | crates/mbe/src/expander/matcher.rs | 53 | ||||
| -rw-r--r-- | crates/mbe/src/tt_iter.rs | 43 |
2 files changed, 53 insertions, 43 deletions
diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs index b6c5c1026e..d7a745860c 100644 --- a/crates/mbe/src/expander/matcher.rs +++ b/crates/mbe/src/expander/matcher.rs @@ -837,7 +837,7 @@ impl<'a> TtIter<'a> { }, Err(_) => false, }, - Separator::Puncts(lhss) if idx < lhss.len() => match fork.expect_punct() { + Separator::Puncts(lhss) if idx < lhss.len() => match fork.expect_single_punct() { Ok(rhs) => rhs.char == lhss[idx].char, Err(_) => false, }, @@ -850,52 +850,21 @@ impl<'a> TtIter<'a> { } fn expect_tt(&mut self) -> Result<tt::TokenTree, ()> { - match self.peek_n(0) { - Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) if punct.char == '\'' => { - return self.expect_lifetime(); - } - _ => (), - } - - let tt = self.next().ok_or(())?.clone(); - let punct = match tt { - tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if punct.spacing == tt::Spacing::Joint => { - punct - } - _ => return Ok(tt), - }; - - 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.char, Some(p3.char)), - (Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p2))), _) => (p2.char, None), - _ => return Ok(tt), - }; - - match (punct.char, second, third) { - ('.', '.', Some('.' | '=')) | ('<', '<', Some('=')) | ('>', '>', Some('=')) => { - let tt2 = self.next().unwrap().clone(); - let tt3 = self.next().unwrap().clone(); - Ok(tt::Subtree { delimiter: None, token_trees: vec![tt, tt2, tt3] }.into()) - } - ('-' | '!' | '*' | '/' | '&' | '%' | '^' | '+' | '<' | '=' | '>' | '|', '=', _) - | ('-' | '=' | '>', '>', _) - | (':', ':', _) - | ('.', '.', _) - | ('&', '&', _) - | ('<', '<', _) - | ('|', '|', _) => { - let tt2 = self.next().unwrap().clone(); - Ok(tt::Subtree { delimiter: None, token_trees: vec![tt, tt2] }.into()) + if let Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) = self.peek_n(0) { + if punct.char == '\'' { + self.expect_lifetime() + } else { + let puncts = self.expect_glued_punct()?; + let token_trees = puncts.into_iter().map(|p| tt::Leaf::Punct(p).into()).collect(); + Ok(tt::TokenTree::Subtree(tt::Subtree { delimiter: None, token_trees })) } - _ => Ok(tt), + } else { + self.next().ok_or(()).cloned() } } fn expect_lifetime(&mut self) -> Result<tt::TokenTree, ()> { - let punct = self.expect_punct()?; + let punct = self.expect_single_punct()?; if punct.char != '\'' { return Err(()); } 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, |