diff options
Diffstat (limited to 'crates')
-rw-r--r-- | crates/hir_ty/src/diagnostics/match_check.rs | 28 | ||||
-rw-r--r-- | crates/hir_ty/src/infer.rs | 2 | ||||
-rw-r--r-- | crates/hir_ty/src/infer/pat.rs | 7 |
3 files changed, 35 insertions, 2 deletions
diff --git a/crates/hir_ty/src/diagnostics/match_check.rs b/crates/hir_ty/src/diagnostics/match_check.rs index a9a99f57a..c8e1b23de 100644 --- a/crates/hir_ty/src/diagnostics/match_check.rs +++ b/crates/hir_ty/src/diagnostics/match_check.rs | |||
@@ -100,10 +100,19 @@ impl<'a> PatCtxt<'a> { | |||
100 | } | 100 | } |
101 | 101 | ||
102 | pub(crate) fn lower_pattern(&mut self, pat: hir_def::expr::PatId) -> Pat { | 102 | pub(crate) fn lower_pattern(&mut self, pat: hir_def::expr::PatId) -> Pat { |
103 | // FIXME: implement pattern adjustments (implicit pattern dereference; "RFC 2005-match-ergonomics") | 103 | // XXX(iDawer): Collecting pattern adjustments feels imprecise to me. |
104 | // When lowering of & and box patterns are implemented this should be tested | ||
105 | // in a manner of `match_ergonomics_issue_9095` test. | ||
106 | // Pattern adjustment is part of RFC 2005-match-ergonomics. | ||
104 | // More info https://github.com/rust-lang/rust/issues/42640#issuecomment-313535089 | 107 | // More info https://github.com/rust-lang/rust/issues/42640#issuecomment-313535089 |
105 | let unadjusted_pat = self.lower_pattern_unadjusted(pat); | 108 | let unadjusted_pat = self.lower_pattern_unadjusted(pat); |
106 | unadjusted_pat | 109 | self.infer.pat_adjustments.get(&pat).map(|it| &**it).unwrap_or_default().iter().rev().fold( |
110 | unadjusted_pat, | ||
111 | |subpattern, ref_ty| Pat { | ||
112 | ty: ref_ty.clone(), | ||
113 | kind: Box::new(PatKind::Deref { subpattern }), | ||
114 | }, | ||
115 | ) | ||
107 | } | 116 | } |
108 | 117 | ||
109 | fn lower_pattern_unadjusted(&mut self, pat: hir_def::expr::PatId) -> Pat { | 118 | fn lower_pattern_unadjusted(&mut self, pat: hir_def::expr::PatId) -> Pat { |
@@ -1236,6 +1245,21 @@ fn main(f: Foo) { | |||
1236 | ); | 1245 | ); |
1237 | } | 1246 | } |
1238 | 1247 | ||
1248 | #[test] | ||
1249 | fn match_ergonomics_issue_9095() { | ||
1250 | check_diagnostics( | ||
1251 | r#" | ||
1252 | enum Foo<T> { A(T) } | ||
1253 | fn main() { | ||
1254 | match &Foo::A(true) { | ||
1255 | _ => {} | ||
1256 | Foo::A(_) => {} | ||
1257 | } | ||
1258 | } | ||
1259 | "#, | ||
1260 | ); | ||
1261 | } | ||
1262 | |||
1239 | mod false_negatives { | 1263 | mod false_negatives { |
1240 | //! The implementation of match checking here is a work in progress. As we roll this out, we | 1264 | //! The implementation of match checking here is a work in progress. As we roll this out, we |
1241 | //! prefer false negatives to false positives (ideally there would be no false positives). This | 1265 | //! prefer false negatives to false positives (ideally there would be no false positives). This |
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs index 7a4268819..0e9f777da 100644 --- a/crates/hir_ty/src/infer.rs +++ b/crates/hir_ty/src/infer.rs | |||
@@ -150,6 +150,8 @@ pub struct InferenceResult { | |||
150 | type_mismatches: FxHashMap<ExprOrPatId, TypeMismatch>, | 150 | type_mismatches: FxHashMap<ExprOrPatId, TypeMismatch>, |
151 | /// Interned Unknown to return references to. | 151 | /// Interned Unknown to return references to. |
152 | standard_types: InternedStandardTypes, | 152 | standard_types: InternedStandardTypes, |
153 | /// Stores the types which were implicitly dereferenced in pattern binding modes. | ||
154 | pub pat_adjustments: FxHashMap<PatId, Vec<Ty>>, | ||
153 | } | 155 | } |
154 | 156 | ||
155 | impl InferenceResult { | 157 | impl InferenceResult { |
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs index 83e0a7a9e..a21f44d6a 100644 --- a/crates/hir_ty/src/infer/pat.rs +++ b/crates/hir_ty/src/infer/pat.rs | |||
@@ -101,7 +101,9 @@ impl<'a> InferenceContext<'a> { | |||
101 | let mut expected = self.resolve_ty_shallow(expected); | 101 | let mut expected = self.resolve_ty_shallow(expected); |
102 | 102 | ||
103 | if is_non_ref_pat(&body, pat) { | 103 | if is_non_ref_pat(&body, pat) { |
104 | let mut pat_adjustments = Vec::new(); | ||
104 | while let Some((inner, _lifetime, mutability)) = expected.as_reference() { | 105 | while let Some((inner, _lifetime, mutability)) = expected.as_reference() { |
106 | pat_adjustments.push(expected.clone()); | ||
105 | expected = self.resolve_ty_shallow(inner); | 107 | expected = self.resolve_ty_shallow(inner); |
106 | default_bm = match default_bm { | 108 | default_bm = match default_bm { |
107 | BindingMode::Move => BindingMode::Ref(mutability), | 109 | BindingMode::Move => BindingMode::Ref(mutability), |
@@ -109,6 +111,11 @@ impl<'a> InferenceContext<'a> { | |||
109 | BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability), | 111 | BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability), |
110 | } | 112 | } |
111 | } | 113 | } |
114 | |||
115 | if !pat_adjustments.is_empty() { | ||
116 | pat_adjustments.shrink_to_fit(); | ||
117 | self.result.pat_adjustments.insert(pat, pat_adjustments); | ||
118 | } | ||
112 | } else if let Pat::Ref { .. } = &body[pat] { | 119 | } else if let Pat::Ref { .. } = &body[pat] { |
113 | cov_mark::hit!(match_ergonomics_ref); | 120 | cov_mark::hit!(match_ergonomics_ref); |
114 | // When you encounter a `&pat` pattern, reset to Move. | 121 | // When you encounter a `&pat` pattern, reset to Move. |