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authorbors[bot] <26634292+bors[bot]@users.noreply.github.com>2020-11-24 15:13:25 +0000
committerGitHub <[email protected]>2020-11-24 15:13:25 +0000
commit67d45851bf2257f6f255fb6863163a6836816cff (patch)
tree4624bd445774dd7a6eb1cf12ccfac9f105948c81 /crates
parentf7e63bdf916ed168dd676f44a2c59feb4f5ff131 (diff)
parenta5efefd3d788a6c5a7fb6a56a0da32f9bf62584e (diff)
Merge #6618
6618: Properly infer tuple patterns when encountering ellipsis r=Veykril a=Veykril We basically just split the subpatterns into two halves when the ellipsis is present and then offset the latter half to account for the ignored bindings. Fixes #6616 Co-authored-by: Lukas Wirth <[email protected]>
Diffstat (limited to 'crates')
-rw-r--r--crates/hir_ty/src/infer/pat.rs46
-rw-r--r--crates/hir_ty/src/tests/patterns.rs95
2 files changed, 129 insertions, 12 deletions
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs
index cde2ab82b..b70ec55eb 100644
--- a/crates/hir_ty/src/infer/pat.rs
+++ b/crates/hir_ty/src/infer/pat.rs
@@ -23,6 +23,7 @@ impl<'a> InferenceContext<'a> {
23 expected: &Ty, 23 expected: &Ty,
24 default_bm: BindingMode, 24 default_bm: BindingMode,
25 id: PatId, 25 id: PatId,
26 ellipsis: Option<usize>,
26 ) -> Ty { 27 ) -> Ty {
27 let (ty, def) = self.resolve_variant(path); 28 let (ty, def) = self.resolve_variant(path);
28 let var_data = def.map(|it| variant_data(self.db.upcast(), it)); 29 let var_data = def.map(|it| variant_data(self.db.upcast(), it));
@@ -34,8 +35,15 @@ impl<'a> InferenceContext<'a> {
34 let substs = ty.substs().unwrap_or_else(Substs::empty); 35 let substs = ty.substs().unwrap_or_else(Substs::empty);
35 36
36 let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default(); 37 let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default();
38 let (pre, post) = match ellipsis {
39 Some(idx) => subpats.split_at(idx),
40 None => (&subpats[..], &[][..]),
41 };
42 let post_idx_offset = field_tys.iter().count() - post.len();
37 43
38 for (i, &subpat) in subpats.iter().enumerate() { 44 let pre_iter = pre.iter().enumerate();
45 let post_iter = (post_idx_offset..).zip(post.iter());
46 for (i, &subpat) in pre_iter.chain(post_iter) {
39 let expected_ty = var_data 47 let expected_ty = var_data
40 .as_ref() 48 .as_ref()
41 .and_then(|d| d.field(&Name::new_tuple_field(i))) 49 .and_then(|d| d.field(&Name::new_tuple_field(i)))
@@ -111,20 +119,29 @@ impl<'a> InferenceContext<'a> {
111 let expected = expected; 119 let expected = expected;
112 120
113 let ty = match &body[pat] { 121 let ty = match &body[pat] {
114 Pat::Tuple { ref args, .. } => { 122 &Pat::Tuple { ref args, ellipsis } => {
115 let expectations = match expected.as_tuple() { 123 let expectations = match expected.as_tuple() {
116 Some(parameters) => &*parameters.0, 124 Some(parameters) => &*parameters.0,
117 _ => &[], 125 _ => &[],
118 }; 126 };
119 let expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
120 127
121 let inner_tys = args 128 let (pre, post) = match ellipsis {
122 .iter() 129 Some(idx) => args.split_at(idx),
123 .zip(expectations_iter) 130 None => (&args[..], &[][..]),
124 .map(|(&pat, ty)| self.infer_pat(pat, ty, default_bm)) 131 };
125 .collect(); 132 let n_uncovered_patterns = expectations.len().saturating_sub(args.len());
133 let mut expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
134 let mut infer_pat = |(&pat, ty)| self.infer_pat(pat, ty, default_bm);
135
136 let mut inner_tys = Vec::with_capacity(n_uncovered_patterns + args.len());
137 inner_tys.extend(pre.iter().zip(expectations_iter.by_ref()).map(&mut infer_pat));
138 inner_tys.extend(expectations_iter.by_ref().take(n_uncovered_patterns).cloned());
139 inner_tys.extend(post.iter().zip(expectations_iter).map(infer_pat));
126 140
127 Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys)) 141 Ty::apply(
142 TypeCtor::Tuple { cardinality: inner_tys.len() as u16 },
143 Substs(inner_tys.into()),
144 )
128 } 145 }
129 Pat::Or(ref pats) => { 146 Pat::Or(ref pats) => {
130 if let Some((first_pat, rest)) = pats.split_first() { 147 if let Some((first_pat, rest)) = pats.split_first() {
@@ -150,9 +167,14 @@ impl<'a> InferenceContext<'a> {
150 let subty = self.infer_pat(*pat, expectation, default_bm); 167 let subty = self.infer_pat(*pat, expectation, default_bm);
151 Ty::apply_one(TypeCtor::Ref(*mutability), subty) 168 Ty::apply_one(TypeCtor::Ref(*mutability), subty)
152 } 169 }
153 Pat::TupleStruct { path: p, args: subpats, .. } => { 170 Pat::TupleStruct { path: p, args: subpats, ellipsis } => self.infer_tuple_struct_pat(
154 self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm, pat) 171 p.as_ref(),
155 } 172 subpats,
173 expected,
174 default_bm,
175 pat,
176 *ellipsis,
177 ),
156 Pat::Record { path: p, args: fields, ellipsis: _ } => { 178 Pat::Record { path: p, args: fields, ellipsis: _ } => {
157 self.infer_record_pat(p.as_ref(), fields, expected, default_bm, pat) 179 self.infer_record_pat(p.as_ref(), fields, expected, default_bm, pat)
158 } 180 }
diff --git a/crates/hir_ty/src/tests/patterns.rs b/crates/hir_ty/src/tests/patterns.rs
index 6a965ac4f..5a5f48fd0 100644
--- a/crates/hir_ty/src/tests/patterns.rs
+++ b/crates/hir_ty/src/tests/patterns.rs
@@ -679,3 +679,98 @@ fn box_pattern() {
679 "#]], 679 "#]],
680 ); 680 );
681} 681}
682
683#[test]
684fn tuple_ellipsis_pattern() {
685 check_infer(
686 r#"
687fn foo(tuple: (u8, i16, f32)) {
688 match tuple {
689 (.., b, c) => {},
690 (a, .., c) => {},
691 (a, b, ..) => {},
692 (a, b) => {/*too short*/}
693 (a, b, c, d) => {/*too long*/}
694 _ => {}
695 }
696}"#,
697 expect![[r#"
698 7..12 'tuple': (u8, i16, f32)
699 30..224 '{ ... } }': ()
700 36..222 'match ... }': ()
701 42..47 'tuple': (u8, i16, f32)
702 58..68 '(.., b, c)': (u8, i16, f32)
703 63..64 'b': i16
704 66..67 'c': f32
705 72..74 '{}': ()
706 84..94 '(a, .., c)': (u8, i16, f32)
707 85..86 'a': u8
708 92..93 'c': f32
709 98..100 '{}': ()
710 110..120 '(a, b, ..)': (u8, i16, f32)
711 111..112 'a': u8
712 114..115 'b': i16
713 124..126 '{}': ()
714 136..142 '(a, b)': (u8, i16, f32)
715 137..138 'a': u8
716 140..141 'b': i16
717 146..161 '{/*too short*/}': ()
718 170..182 '(a, b, c, d)': (u8, i16, f32, {unknown})
719 171..172 'a': u8
720 174..175 'b': i16
721 177..178 'c': f32
722 180..181 'd': {unknown}
723 186..200 '{/*too long*/}': ()
724 209..210 '_': (u8, i16, f32)
725 214..216 '{}': ()
726 "#]],
727 );
728}
729
730#[test]
731fn tuple_struct_ellipsis_pattern() {
732 check_infer(
733 r#"
734struct Tuple(u8, i16, f32);
735fn foo(tuple: Tuple) {
736 match tuple {
737 Tuple(.., b, c) => {},
738 Tuple(a, .., c) => {},
739 Tuple(a, b, ..) => {},
740 Tuple(a, b) => {/*too short*/}
741 Tuple(a, b, c, d) => {/*too long*/}
742 _ => {}
743 }
744}"#,
745 expect![[r#"
746 35..40 'tuple': Tuple
747 49..268 '{ ... } }': ()
748 55..266 'match ... }': ()
749 61..66 'tuple': Tuple
750 77..92 'Tuple(.., b, c)': Tuple
751 87..88 'b': i16
752 90..91 'c': f32
753 96..98 '{}': ()
754 108..123 'Tuple(a, .., c)': Tuple
755 114..115 'a': u8
756 121..122 'c': f32
757 127..129 '{}': ()
758 139..154 'Tuple(a, b, ..)': Tuple
759 145..146 'a': u8
760 148..149 'b': i16
761 158..160 '{}': ()
762 170..181 'Tuple(a, b)': Tuple
763 176..177 'a': u8
764 179..180 'b': i16
765 185..200 '{/*too short*/}': ()
766 209..226 'Tuple(... c, d)': Tuple
767 215..216 'a': u8
768 218..219 'b': i16
769 221..222 'c': f32
770 224..225 'd': {unknown}
771 230..244 '{/*too long*/}': ()
772 253..254 '_': Tuple
773 258..260 '{}': ()
774 "#]],
775 );
776}