bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/mbe/src/expander/matcher.rs')
-rw-r--r--crates/mbe/src/expander/matcher.rs38
1 files changed, 18 insertions, 20 deletions
diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs
index bcda2381a4..910724411d 100644
--- a/crates/mbe/src/expander/matcher.rs
+++ b/crates/mbe/src/expander/matcher.rs
@@ -571,18 +571,18 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree) -> Match {
if !error_items.is_empty() {
error_recover_item = error_items.pop().map(|it| it.bindings);
- } else if !eof_items.is_empty() {
- error_recover_item = Some(eof_items[0].bindings.clone());
+ } else if let [state, ..] = &*eof_items {
+ error_recover_item = Some(state.bindings.clone());
}
// We need to do some post processing after the `match_loop_inner`.
// If we reached the EOF, check that there is EXACTLY ONE possible matcher. Otherwise,
// either the parse is ambiguous (which should never happen) or there is a syntax error.
if src.peek_n(0).is_none() && stack.is_empty() {
- if eof_items.len() == 1 {
+ if let [state] = &*eof_items {
// remove all errors, because it is the correct answer !
res = Match::default();
- res.bindings = bindings_builder.build(&eof_items[0].bindings);
+ res.bindings = bindings_builder.build(&state.bindings);
} else {
// Error recovery
if let Some(item) = error_recover_item {
@@ -598,10 +598,10 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree) -> Match {
//
// Another possibility is that we need to call out to parse some rust nonterminal
// (black-box) parser. However, if there is not EXACTLY ONE of these, something is wrong.
- if (bb_items.is_empty() && next_items.is_empty())
- || (!bb_items.is_empty() && !next_items.is_empty())
- || bb_items.len() > 1
- {
+ let has_leftover_tokens = (bb_items.is_empty() && next_items.is_empty())
+ || !(bb_items.is_empty() || next_items.is_empty())
+ || bb_items.len() > 1;
+ if has_leftover_tokens {
res.unmatched_tts += src.len();
while let Some(it) = stack.pop() {
src = it;
@@ -624,7 +624,11 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree) -> Match {
stack.push(src.clone());
src = TtIter::new(subtree);
}
- None if !stack.is_empty() => src = stack.pop().unwrap(),
+ None => {
+ if let Some(iter) = stack.pop() {
+ src = iter;
+ }
+ }
_ => (),
}
}
@@ -662,29 +666,23 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree) -> Match {
fn match_leaf(lhs: &tt::Leaf, src: &mut TtIter) -> Result<(), ExpandError> {
let rhs = match src.expect_leaf() {
Ok(l) => l,
- Err(()) => {
- return Err(err!("expected leaf: `{}`", lhs));
- }
+ Err(()) => return Err(err!("expected leaf: `{}`", lhs)),
};
match (lhs, rhs) {
(
tt::Leaf::Punct(tt::Punct { char: lhs, .. }),
tt::Leaf::Punct(tt::Punct { char: rhs, .. }),
- ) if lhs == rhs => (),
+ ) if lhs == rhs => Ok(()),
(
tt::Leaf::Ident(tt::Ident { text: lhs, .. }),
tt::Leaf::Ident(tt::Ident { text: rhs, .. }),
- ) if lhs == rhs => (),
+ ) if lhs == rhs => Ok(()),
(
tt::Leaf::Literal(tt::Literal { text: lhs, .. }),
tt::Leaf::Literal(tt::Literal { text: rhs, .. }),
- ) if lhs == rhs => (),
- _ => {
- return Err(ExpandError::UnexpectedToken);
- }
+ ) if lhs == rhs => Ok(()),
+ _ => Err(ExpandError::UnexpectedToken),
}
-
- Ok(())
}
fn match_meta_var(kind: &str, input: &mut TtIter) -> ExpandResult<Option<Fragment>> {