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authorJade <[email protected]>2021-05-11 13:06:33 +0100
committerJade <[email protected]>2021-05-11 13:25:19 +0100
commitdc63fea427280ff278bf89a8b9c78df606009910 (patch)
tree5fb6eae3df58a7c5bc3bc5a1220dd9a5d6d3ea86 /crates/hir_ty/src/infer
parent77f0c92fd8311bccc001ddaf9eb72662d35e9836 (diff)
Add basic support for array lengths in types
This recognizes `let a = [1u8, 2, 3]` as having type `[u8; 3]` instead of the previous `[u8; _]`. Byte strings and `[0u8; 2]` kinds of range array declarations are unsupported as before. I don't know why a bunch of our rustc tests had single quotes inside strings un-escaped by `UPDATE_EXPECT=1 cargo t`, but I don't think it's bad? Maybe something in a nightly?
Diffstat (limited to 'crates/hir_ty/src/infer')
-rw-r--r--crates/hir_ty/src/infer/expr.rs26
1 files changed, 20 insertions, 6 deletions
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 50497eecb..9aec8a236 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -3,7 +3,7 @@
3use std::iter::{repeat, repeat_with}; 3use std::iter::{repeat, repeat_with};
4use std::{mem, sync::Arc}; 4use std::{mem, sync::Arc};
5 5
6use chalk_ir::{cast::Cast, fold::Shift, Mutability, TyVariableKind}; 6use chalk_ir::{cast::Cast, fold::Shift, ConstData, Mutability, TyVariableKind};
7use hir_def::{ 7use hir_def::{
8 expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp}, 8 expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
9 path::{GenericArg, GenericArgs}, 9 path::{GenericArg, GenericArgs},
@@ -15,7 +15,9 @@ use stdx::always;
15use syntax::ast::RangeOp; 15use syntax::ast::RangeOp;
16 16
17use crate::{ 17use crate::{
18 autoderef, dummy_usize_const, 18 autoderef,
19 consts::ConstScalar,
20 dummy_usize_const,
19 lower::lower_to_chalk_mutability, 21 lower::lower_to_chalk_mutability,
20 mapping::from_chalk, 22 mapping::from_chalk,
21 method_resolution, op, 23 method_resolution, op,
@@ -23,7 +25,7 @@ use crate::{
23 static_lifetime, to_chalk_trait_id, 25 static_lifetime, to_chalk_trait_id,
24 traits::FnTrait, 26 traits::FnTrait,
25 utils::{generics, Generics}, 27 utils::{generics, Generics},
26 AdtId, Binders, CallableDefId, FnPointer, FnSig, FnSubst, InEnvironment, Interner, 28 AdtId, Binders, CallableDefId, ConstValue, FnPointer, FnSig, FnSubst, InEnvironment, Interner,
27 ProjectionTyExt, Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyExt, TyKind, 29 ProjectionTyExt, Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyExt, TyKind,
28}; 30};
29 31
@@ -717,11 +719,12 @@ impl<'a> InferenceContext<'a> {
717 _ => self.table.new_type_var(), 719 _ => self.table.new_type_var(),
718 }; 720 };
719 721
720 match array { 722 let len = match array {
721 Array::ElementList(items) => { 723 Array::ElementList(items) => {
722 for expr in items.iter() { 724 for expr in items.iter() {
723 self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone())); 725 self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone()));
724 } 726 }
727 Some(items.len())
725 } 728 }
726 Array::Repeat { initializer, repeat } => { 729 Array::Repeat { initializer, repeat } => {
727 self.infer_expr_coerce( 730 self.infer_expr_coerce(
@@ -734,10 +737,20 @@ impl<'a> InferenceContext<'a> {
734 TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner), 737 TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner),
735 ), 738 ),
736 ); 739 );
740 // FIXME: support length for Repeat array expressions
741 None
737 } 742 }
738 } 743 };
739 744
740 TyKind::Array(elem_ty, dummy_usize_const()).intern(&Interner) 745 let cd = ConstData {
746 ty: TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner),
747 value: ConstValue::Concrete(chalk_ir::ConcreteConst {
748 interned: len
749 .map(|len| ConstScalar::Usize(len))
750 .unwrap_or(ConstScalar::Unknown),
751 }),
752 };
753 TyKind::Array(elem_ty, cd.intern(&Interner)).intern(&Interner)
741 } 754 }
742 Expr::Literal(lit) => match lit { 755 Expr::Literal(lit) => match lit {
743 Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner), 756 Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner),
@@ -747,6 +760,7 @@ impl<'a> InferenceContext<'a> {
747 } 760 }
748 Literal::ByteString(..) => { 761 Literal::ByteString(..) => {
749 let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(&Interner); 762 let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(&Interner);
763
750 let array_type = 764 let array_type =
751 TyKind::Array(byte_type, dummy_usize_const()).intern(&Interner); 765 TyKind::Array(byte_type, dummy_usize_const()).intern(&Interner);
752 TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(&Interner) 766 TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(&Interner)