diff options
author | Lukas Wirth <[email protected]> | 2020-11-24 13:52:46 +0000 |
---|---|---|
committer | Lukas Wirth <[email protected]> | 2020-11-24 15:11:40 +0000 |
commit | a5efefd3d788a6c5a7fb6a56a0da32f9bf62584e (patch) | |
tree | 727dfd24c866d9859c6fc497474f0637159aba1d /crates/hir_ty/src/infer | |
parent | 35dd62e915905b6a93e2069a6d155cdf00cd254a (diff) |
Properly infer tuple struct patterns when encountering ellipsis
Diffstat (limited to 'crates/hir_ty/src/infer')
-rw-r--r-- | crates/hir_ty/src/infer/pat.rs | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs index b3fd74eab..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))) |
@@ -111,23 +119,23 @@ 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, ellipsis } => { | 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 | 127 | ||
120 | let (pre, post) = match ellipsis { | 128 | let (pre, post) = match ellipsis { |
121 | &Some(idx) => args.split_at(idx), | 129 | Some(idx) => args.split_at(idx), |
122 | None => (&args[..], &[][..]), | 130 | None => (&args[..], &[][..]), |
123 | }; | 131 | }; |
124 | let uncovered_range = pre.len()..expectations.len().saturating_sub(post.len()); | 132 | let n_uncovered_patterns = expectations.len().saturating_sub(args.len()); |
125 | let mut expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown)); | 133 | let mut expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown)); |
126 | let mut infer_pat = |(&pat, ty)| self.infer_pat(pat, ty, default_bm); | 134 | let mut infer_pat = |(&pat, ty)| self.infer_pat(pat, ty, default_bm); |
127 | 135 | ||
128 | let mut inner_tys = Vec::with_capacity(expectations.len()); | 136 | let mut inner_tys = Vec::with_capacity(n_uncovered_patterns + args.len()); |
129 | inner_tys.extend(pre.iter().zip(expectations_iter.by_ref()).map(&mut infer_pat)); | 137 | inner_tys.extend(pre.iter().zip(expectations_iter.by_ref()).map(&mut infer_pat)); |
130 | inner_tys.extend(expectations_iter.by_ref().take(uncovered_range.len()).cloned()); | 138 | inner_tys.extend(expectations_iter.by_ref().take(n_uncovered_patterns).cloned()); |
131 | inner_tys.extend(post.iter().zip(expectations_iter).map(infer_pat)); | 139 | inner_tys.extend(post.iter().zip(expectations_iter).map(infer_pat)); |
132 | 140 | ||
133 | Ty::apply( | 141 | Ty::apply( |
@@ -159,9 +167,14 @@ impl<'a> InferenceContext<'a> { | |||
159 | let subty = self.infer_pat(*pat, expectation, default_bm); | 167 | let subty = self.infer_pat(*pat, expectation, default_bm); |
160 | Ty::apply_one(TypeCtor::Ref(*mutability), subty) | 168 | Ty::apply_one(TypeCtor::Ref(*mutability), subty) |
161 | } | 169 | } |
162 | Pat::TupleStruct { path: p, args: subpats, .. } => { | 170 | Pat::TupleStruct { path: p, args: subpats, ellipsis } => self.infer_tuple_struct_pat( |
163 | self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm, pat) | 171 | p.as_ref(), |
164 | } | 172 | subpats, |
173 | expected, | ||
174 | default_bm, | ||
175 | pat, | ||
176 | *ellipsis, | ||
177 | ), | ||
165 | Pat::Record { path: p, args: fields, ellipsis: _ } => { | 178 | Pat::Record { path: p, args: fields, ellipsis: _ } => { |
166 | 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) |
167 | } | 180 | } |