Comments only

Mon Sep 18 16:43:36 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
  * Comments only
  Sun Aug  6 17:18:44 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
    * Comments only
    Tue Jul 25 12:06:00 EDT 2006  simonpj@microsoft.com

diff --git a/compiler/basicTypes/Var.lhs b/compiler/basicTypes/Var.lhs
index d4bf400..f98fdae 100644 (file)
--- a/compiler/basicTypes/Var.lhs
+++ b/compiler/basicTypes/Var.lhs
@@ -203,13 +203,15 @@ mkTcTyVar name kind details
        }
 
 mkWildCoVar :: Kind -> TyVar
+-- A type variable that is never referred to,
+-- so its unique doesn't matter
 mkWildCoVar kind 
   = TyVar { varName = mkSysTvName wild_uniq FSLIT("co_wild"),
             realUnique = _ILIT(1),
             tyVarKind = kind,
             isCoercionVar = True }
   where
-    wild_uniq = (mkBuiltinUnique 1)
+    wild_uniq = mkBuiltinUnique 1
 \end{code}
 
 %************************************************************************

diff --git a/compiler/types/TypeRep.lhs b/compiler/types/TypeRep.lhs
index 544b822..b0b5c63 100644 (file)
--- a/compiler/types/TypeRep.lhs
+++ b/compiler/types/TypeRep.lhs
@@ -192,8 +192,11 @@ data Type
        TyVar
        Type    
 
-  | PredTy             -- A high level source type 
-       PredType        -- ...can be expanded to a representation type...
+  | PredTy             -- The type of evidence for a type predictate
+       PredType        -- Can be expanded to a representation type.
+       -- NB: A PredTy (EqPred _ _) can appear only as the kind
+       --     of a coercion variable; never as the argument or result
+       --     of a FunTy (unlike ClassP, IParam)
 
   | NoteTy             -- A type with a note attached
        TyNote