Merge pull request #148 from leodasvacas/shadowing-tests

Small things

Author: nikomatsakis

src/ir/lowering.rs

@@ -21,6 +21,8 @@ struct Env<'k> {
     type_ids: &'k TypeIds,
     type_kinds: &'k TypeKinds,
     associated_ty_infos: &'k AssociatedTyInfos,
+    /// Parameter identifiers are used as keys, therefore
+    /// all indentifiers in an environment must be unique (no shadowing).
     parameter_map: ParameterMap,
 }
 
@@ -84,7 +86,7 @@ impl<'k> Env<'k> {
             .chain(binders)
             .collect();
         if parameter_map.len() != self.parameter_map.len() + len {
-            bail!("duplicate parameters");
+            bail!("duplicate or shadowed parameters");
         }
         Ok(Env {
             parameter_map,

src/ir/lowering/test.rs

@@ -362,7 +362,7 @@ fn duplicate_parameters() {
         }
 
         error_msg {
-            "duplicate parameters"
+            "duplicate or shadowed parameters"
         }
     }
 
@@ -374,7 +374,18 @@ fn duplicate_parameters() {
         }
 
         error_msg {
-            "duplicate parameters"
+            "duplicate or shadowed parameters"
+        }
+    }
+
+    lowering_error! {
+        program {
+            struct fn<'a> { }
+            struct Foo<'a> {
+                a: for<'a> fn<'a>
+            }
+        } error_msg {
+            "duplicate or shadowed parameters"
         }
     }
 }

src/solve/infer.rs

@@ -89,6 +89,7 @@ impl InferenceTable {
     crate fn new_universe(&mut self) -> UniverseIndex {
         let u = self.max_universe.next();
         self.max_universe = u;
+        debug!("new_universe: {:?}", u);
         u
     }
 

src/solve/test.rs

@@ -2371,6 +2371,7 @@ fn quantified_types() {
         program {
             trait Foo { }
             struct fn<'a> { }
+            struct fn2<'a, 'b> { }
             impl Foo for for<'a> fn<'a> { }
         }
 
@@ -2380,6 +2381,12 @@ fn quantified_types() {
             "Unique"
         }
 
+        goal {
+            for<'a, 'b> fn2<'a, 'b> = for<'b, 'a> fn2<'a, 'b>
+        } yields {
+            "Unique"
+        }
+
         goal {
             forall<'a> { fn<'a>: Foo }
         } yields {