Merge pull request #378 from crlf0710/fn2substitution

Change `Vec<Parameter>` to `Substitution` in `Fn`

Author: nikomatsakis

chalk-integration/src/lowering.rs

@@ -1,6 +1,8 @@
 use chalk_ir::cast::{Cast, Caster};
 use chalk_ir::interner::ChalkIr;
-use chalk_ir::{self, AssocTypeId, BoundVar, DebruijnIndex, ImplId, StructId, TraitId};
+use chalk_ir::{
+    self, AssocTypeId, BoundVar, DebruijnIndex, ImplId, StructId, Substitution, TraitId,
+};
 use chalk_parse::ast::*;
 use chalk_rust_ir as rust_ir;
 use chalk_rust_ir::{Anonymize, AssociatedTyValueId, IntoWhereClauses, ToParameter};
@@ -1070,7 +1072,10 @@ impl LowerTy for Ty {
 
                 let function = chalk_ir::Fn {
                     num_binders: lifetime_names.len(),
-                    parameters: vec![ty.lower(&quantified_env)?.cast(interner)],
+                    substitution: Substitution::from(
+                        interner,
+                        Some(ty.lower(&quantified_env)?.cast(interner)),
+                    ),
                 };
                 Ok(chalk_ir::TyData::Function(function).intern(interner))
             }

chalk-ir/src/debug.rs

@@ -163,9 +163,9 @@ impl<I: Interner> Debug for Fn<I> {
         // FIXME -- we should introduce some names or something here
         let Fn {
             num_binders,
-            parameters,
+            substitution,
         } = self;
-        write!(fmt, "for<{}> {:?}", num_binders, parameters)
+        write!(fmt, "for<{}> {:?}", num_binders, substitution)
     }
 }
 

chalk-ir/src/fold/binder_impls.rs

@@ -19,11 +19,11 @@ impl<I: Interner, TI: TargetInterner<I>> Fold<I, TI> for Fn<I> {
     {
         let Fn {
             num_binders,
-            parameters,
+            substitution,
         } = self;
         Ok(Fn {
             num_binders: *num_binders,
-            parameters: parameters.fold_with(folder, outer_binder.shifted_in())?,
+            substitution: substitution.fold_with(folder, outer_binder.shifted_in())?,
         })
     }
 }

chalk-ir/src/lib.rs

@@ -576,7 +576,7 @@ impl InferenceVar {
 #[derive(Clone, PartialEq, Eq, Hash, HasInterner)]
 pub struct Fn<I: Interner> {
     pub num_binders: usize,
-    pub parameters: Vec<Parameter<I>>,
+    pub substitution: Substitution<I>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, HasInterner)]

chalk-ir/src/macros.rs

@@ -12,7 +12,7 @@ macro_rules! ty {
     (function $n:tt $($arg:tt)*) => {
         $crate::TyData::Function(Fn {
             num_binders: $n,
-            parameters: vec![$(arg!($arg)),*],
+            substitution: $crate::Substitution::from(&chalk_ir::interner::ChalkIr, vec![$(arg!($arg)),*] as Vec<$crate::Parameter<_>>),
         }).intern(&chalk_ir::interner::ChalkIr)
     };
 

chalk-solve/src/clauses.rs

@@ -362,8 +362,8 @@ fn match_ty<I: Interner>(
         TyData::Function(quantified_ty) => {
             builder.push_fact(WellFormed::Ty(ty.clone()));
             quantified_ty
-                .parameters
-                .iter()
+                .substitution
+                .iter(interner)
                 .map(|p| p.assert_ty_ref(interner))
                 .for_each(|ty| match_ty(builder, environment, &ty))
         }

chalk-solve/src/infer/instantiate.rs

@@ -123,15 +123,15 @@ where
     I: Interner,
 {
     type Binders = std::iter::Map<std::ops::Range<usize>, fn(usize) -> chalk_ir::ParameterKind<()>>;
-    type Value = &'a Vec<Parameter<I>>;
+    type Value = &'a Substitution<I>;
 
     fn into_binders_and_value(self) -> (Self::Binders, Self::Value) {
         fn make_lifetime(_: usize) -> ParameterKind<()> {
             ParameterKind::Lifetime(())
         }
 
         let p: fn(usize) -> ParameterKind<()> = make_lifetime;
-        ((0..self.num_binders).map(p), &self.parameters)
+        ((0..self.num_binders).map(p), &self.substitution)
     }
 }
 

chalk-solve/src/solve/slg/resolvent.rs

@@ -418,7 +418,7 @@ impl<'i, I: Interner> Zipper<'i, I> for AnswerSubstitutor<'i, I> {
 
             (TyData::Function(answer), TyData::Function(pending)) => {
                 self.outer_binder.shift_in();
-                Zip::zip_with(self, &answer.parameters, &pending.parameters)?;
+                Zip::zip_with(self, &answer.substitution, &pending.substitution)?;
                 self.outer_binder.shift_out();
                 Ok(())
             }