Parse and lower array types

Author: nathanwhit

chalk-integration/src/lowering.rs

@@ -1395,6 +1395,18 @@ impl LowerTy for Ty {
             })
             .intern(interner)),
 
+            Ty::Array { ty, len } => Ok(chalk_ir::TyData::Apply(chalk_ir::ApplicationTy {
+                name: chalk_ir::TypeName::Array,
+                substitution: chalk_ir::Substitution::from(
+                    interner,
+                    &[
+                        ty.lower(env)?.cast(interner),
+                        len.lower(env)?.cast(interner),
+                    ],
+                ),
+            })
+            .intern(interner)),
+
             Ty::Slice { ty } => Ok(chalk_ir::TyData::Apply(chalk_ir::ApplicationTy {
                 name: chalk_ir::TypeName::Slice,
                 substitution: chalk_ir::Substitution::from_fallible(

chalk-parse/src/ast.rs

@@ -212,6 +212,10 @@ pub enum Ty {
     Slice {
         ty: Box<Ty>,
     },
+    Array {
+        ty: Box<Ty>,
+        len: Box<GenericArg>,
+    },
     Raw {
         mutability: Mutability,
         ty: Box<Ty>,

chalk-parse/src/parser.lalrpop

@@ -239,6 +239,7 @@ TyWithoutId: Ty = {
     "&" <l: Lifetime> "mut" <t:Ty> => Ty::Ref{ mutability: Mutability::Mut, lifetime: l, ty: Box::new(t) },
     "&" <l: Lifetime> <t:Ty> => Ty::Ref{ mutability: Mutability::Not, lifetime: l, ty: Box::new(t) },
     "[" <t:Ty> "]" => Ty::Slice { ty: Box::new(t) }, 
+    "[" <t:Ty> ";" <len:GenericArg> "]" => Ty::Array { ty: Box::new(t), len: Box::new(len) },
 };
 
 ScalarType: ScalarType = {

tests/lowering/mod.rs

@@ -584,3 +584,15 @@ fn fn_defs() {
         }
     }
 }
+
+#[test]
+fn arrays() {
+    lowering_success! {
+        program {
+            struct Baz { }
+            fn foo(bar: [Baz; 3]);
+
+            fn bar<const N>(baz: [Baz; N]);
+        }
+    }
+}