Unnamed repository; edit this file 'description' to name the repository.
| -rw-r--r-- | crates/hir-ty/src/infer/pat.rs | 33 | ||||
| -rw-r--r-- | crates/hir-ty/src/tests/patterns.rs | 45 |
2 files changed, 74 insertions, 4 deletions
diff --git a/crates/hir-ty/src/infer/pat.rs b/crates/hir-ty/src/infer/pat.rs index 5e7320a5dd..53259d66de 100644 --- a/crates/hir-ty/src/infer/pat.rs +++ b/crates/hir-ty/src/infer/pat.rs @@ -14,8 +14,9 @@ use crate::{ consteval::intern_const_scalar, infer::{BindingMode, Expectation, InferenceContext, TypeMismatch}, lower::lower_to_chalk_mutability, - static_lifetime, ConcreteConst, ConstValue, Interner, Substitution, Ty, TyBuilder, TyExt, - TyKind, + primitive::UintTy, + static_lifetime, ConcreteConst, ConstValue, Interner, Scalar, Substitution, Ty, TyBuilder, + TyExt, TyKind, }; use super::PatLike; @@ -294,7 +295,29 @@ impl<'a> InferenceContext<'a> { let start_ty = self.infer_expr(*start, &Expectation::has_type(expected.clone())); self.infer_expr(*end, &Expectation::has_type(start_ty)) } - Pat::Lit(expr) => self.infer_expr(*expr, &Expectation::has_type(expected.clone())), + &Pat::Lit(expr) => { + // FIXME: using `Option` here is a workaround until we can use if-let chains in stable. + let mut pat_ty = None; + + // Like slice patterns, byte string patterns can denote both `&[u8; N]` and `&[u8]`. + if let Expr::Literal(Literal::ByteString(_)) = self.body[expr] { + if let Some((inner, ..)) = expected.as_reference() { + let inner = self.resolve_ty_shallow(inner); + if matches!(inner.kind(Interner), TyKind::Slice(_)) { + let elem_ty = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(Interner); + let slice_ty = TyKind::Slice(elem_ty).intern(Interner); + let ty = TyKind::Ref(Mutability::Not, static_lifetime(), slice_ty) + .intern(Interner); + self.write_expr_ty(expr, ty.clone()); + pat_ty = Some(ty); + } + } + } + + pat_ty.unwrap_or_else(|| { + self.infer_expr(expr, &Expectation::has_type(expected.clone())) + }) + } Pat::Box { inner } => match self.resolve_boxed_box() { Some(box_adt) => { let (inner_ty, alloc_ty) = match expected.as_adt() { @@ -343,7 +366,9 @@ fn is_non_ref_pat(body: &hir_def::body::Body, pat: PatId) -> bool { // FIXME: ConstBlock/Path/Lit might actually evaluate to ref, but inference is unimplemented. Pat::Path(..) => true, Pat::ConstBlock(..) => true, - Pat::Lit(expr) => !matches!(body[*expr], Expr::Literal(Literal::String(..))), + Pat::Lit(expr) => { + !matches!(body[*expr], Expr::Literal(Literal::String(..) | Literal::ByteString(..))) + } Pat::Bind { mode: BindingAnnotation::Mutable | BindingAnnotation::Unannotated, subpat: Some(subpat), diff --git a/crates/hir-ty/src/tests/patterns.rs b/crates/hir-ty/src/tests/patterns.rs index 399553356b..94efe7bc11 100644 --- a/crates/hir-ty/src/tests/patterns.rs +++ b/crates/hir-ty/src/tests/patterns.rs @@ -316,6 +316,51 @@ fn infer_pattern_match_string_literal() { } #[test] +fn infer_pattern_match_byte_string_literal() { + check_infer_with_mismatches( + r#" + //- minicore: index + struct S; + impl<T, const N: usize> core::ops::Index<S> for [T; N] { + type Output = [u8]; + fn index(&self, index: core::ops::RangeFull) -> &Self::Output { + loop {} + } + } + fn test(v: [u8; 3]) { + if let b"foo" = &v[S] {} + if let b"foo" = &v {} + } + "#, + expect![[r#" + 105..109 'self': &[T; N] + 111..116 'index': {unknown} + 157..180 '{ ... }': &[u8] + 167..174 'loop {}': ! + 172..174 '{}': () + 191..192 'v': [u8; 3] + 203..261 '{ ...v {} }': () + 209..233 'if let...[S] {}': () + 212..230 'let b"... &v[S]': bool + 216..222 'b"foo"': &[u8] + 216..222 'b"foo"': &[u8] + 225..230 '&v[S]': &[u8] + 226..227 'v': [u8; 3] + 226..230 'v[S]': [u8] + 228..229 'S': S + 231..233 '{}': () + 238..259 'if let... &v {}': () + 241..256 'let b"foo" = &v': bool + 245..251 'b"foo"': &[u8; 3] + 245..251 'b"foo"': &[u8; 3] + 254..256 '&v': &[u8; 3] + 255..256 'v': [u8; 3] + 257..259 '{}': () + "#]], + ); +} + +#[test] fn infer_pattern_match_or() { check_infer_with_mismatches( r#" |