Parse and lower slice types

Author: nathanwhit

chalk-integration/src/lowering.rs

@@ -1211,6 +1211,15 @@ impl LowerTy for Ty {
             })
             .intern(interner)),
 
+            Ty::Slice { ty } => Ok(chalk_ir::TyData::Apply(chalk_ir::ApplicationTy {
+                name: chalk_ir::TypeName::Slice,
+                substitution: chalk_ir::Substitution::from_fallible(
+                    interner,
+                    std::iter::once(ty.lower(env)),
+                )?,
+            })
+            .intern(interner)),
+
             Ty::Raw { mutability, ty } => Ok(chalk_ir::TyData::Apply(chalk_ir::ApplicationTy {
                 name: chalk_ir::TypeName::Raw(ast_mutability_to_chalk_mutability(
                     mutability.clone(),

chalk-parse/src/ast.rs

@@ -193,6 +193,9 @@ pub enum Ty {
     Scalar {
         ty: ScalarType,
     },
+    Slice {
+        ty: Box<Ty>,
+    },
     Raw {
         mutability: Mutability,
         ty: Box<Ty>,

chalk-parse/src/parser.lalrpop

@@ -208,6 +208,7 @@ TyWithoutFor: Ty = {
     "*" <m: RawMutability> <t:Ty> => Ty::Raw{ mutability: m, ty: Box::new(t) },
     "&" <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) }, 
 };
 
 ScalarType: ScalarType = {