Add assertion checks for mkCoVar/mkTyVar

[ghc-hetmet.git] / compiler / types / Type.lhs

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index a7aeeec..eeacb1a 100644 (file)
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -1,8 +1,9 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1998
 %
-\section[Type]{Type - public interface}
 
+Type - public interface
 
 \begin{code}
 module Type (
@@ -105,31 +106,23 @@ module Type (
 import TypeRep
 
 -- friends:
-import Var     ( Var, TyVar, tyVarKind, tyVarName, 
-                 setTyVarName, setTyVarKind, mkWildCoVar )
+import Var
 import VarEnv
 import VarSet
 
-import OccName ( tidyOccName )
-import Name    ( NamedThing(..), tidyNameOcc )
-import Class   ( Class, classTyCon )
-import PrelNames( openTypeKindTyConKey, unliftedTypeKindTyConKey, 
-                  ubxTupleKindTyConKey, argTypeKindTyConKey )
-import TyCon   ( TyCon, isRecursiveTyCon, isPrimTyCon,
-                 isUnboxedTupleTyCon, isUnLiftedTyCon,
-                 isFunTyCon, isNewTyCon, newTyConRep, newTyConRhs,
-                 isAlgTyCon, tyConArity, isSuperKindTyCon,
-                 tcExpandTyCon_maybe, coreExpandTyCon_maybe,
-                 tyConKind, PrimRep(..), tyConPrimRep, tyConUnique,
-                  isCoercionTyCon_maybe, isCoercionTyCon
-               )
+import OccName
+import Name
+import Class
+import PrelNames
+import TyCon
 
 -- others
-import StaticFlags     ( opt_DictsStrict )
-import Util            ( mapAccumL, seqList, lengthIs, snocView, thenCmp, isEqual, all2 )
+import StaticFlags
+import Util
 import Outputable
-import UniqSet         ( sizeUniqSet )         -- Should come via VarSet
-import Maybe           ( isJust )
+import UniqSet
+
+import Data.Maybe      ( isJust )
 \end{code}
 
 
@@ -448,7 +441,7 @@ repType looks through
        (b) synonyms
        (c) predicates
        (d) usage annotations
-       (e) all newtypes, including recursive ones
+       (e) all newtypes, including recursive ones, but not newtype families
 It's useful in the back end.
 
 \begin{code}
@@ -457,7 +450,7 @@ repType :: Type -> Type
 repType ty | Just ty' <- coreView ty = repType ty'
 repType (ForAllTy _ ty)  = repType ty
 repType (TyConApp tc tys)
-  | isNewTyCon tc       = -- Recursive newtypes are opaque to coreView
+  | isClosedNewTyCon tc  = -- Recursive newtypes are opaque to coreView
                           -- but we must expand them here.  Sure to
                           -- be saturated because repType is only applied
                           -- to types of kind *
@@ -616,7 +609,7 @@ splitRecNewType_maybe :: Type -> Maybe Type
 -- Only applied to types of kind *, hence the newtype is always saturated
 splitRecNewType_maybe ty | Just ty' <- coreView ty = splitRecNewType_maybe ty'
 splitRecNewType_maybe (TyConApp tc tys)
-  | isNewTyCon tc
+  | isClosedNewTyCon tc
   = ASSERT( tys `lengthIs` tyConArity tc )     -- splitRecNewType_maybe only be applied 
                                                --      to *types* (of kind *)
     ASSERT( isRecursiveTyCon tc )              -- Guaranteed by coreView
@@ -1027,9 +1020,13 @@ cmpPredX env (IParam n1 ty1) (IParam n2 ty2) = (n1 `compare` n2) `thenCmp` cmpTy
        -- This comparison is used exclusively (I think) for the
        -- finite map built in TcSimplify
 cmpPredX env (ClassP c1 tys1) (ClassP c2 tys2) = (c1 `compare` c2) `thenCmp` cmpTypesX env tys1 tys2
-cmpPredX env (IParam _ _)     (ClassP _ _)     = LT
-cmpPredX env (ClassP _ _)     (IParam _ _)     = GT
 cmpPredX env (EqPred ty1 ty2) (EqPred ty1' ty2') = (cmpTypeX env ty1 ty1') `thenCmp` (cmpTypeX env ty2 ty2')
+
+-- Constructor order: IParam < ClassP < EqPred
+cmpPredX env (IParam {})     _             = LT
+cmpPredX env (ClassP {})    (IParam {})     = GT
+cmpPredX env (ClassP {})    (EqPred {})     = LT
+cmpPredX env (EqPred {})    _              = GT
 \end{code}
 
 PredTypes are used as a FM key in TcSimplify, 
@@ -1292,7 +1289,7 @@ substTyVarBndr subst@(TvSubst in_scope env) old_var
        | is_co_var = setTyVarKind old_var (substTy subst kind)
        | otherwise = old_var
     kind = tyVarKind old_var
-    is_co_var = isCoercionKind kind
+    is_co_var = isCoVar old_var
 \end{code}
 
 ----------------------------------------------------
@@ -1429,7 +1426,7 @@ isKind k = isSuperKind (typeKind k)
 
 isSubKind :: Kind -> Kind -> Bool
 -- (k1 `isSubKind` k2) checks that k1 <: k2
-isSubKind (TyConApp kc1 []) (TyConApp kc2 []) = kc1 `isSubKindCon` kc1
+isSubKind (TyConApp kc1 []) (TyConApp kc2 []) = kc1 `isSubKindCon` kc2
 isSubKind (FunTy a1 r1) (FunTy a2 r2)        = (a2 `isSubKind` a1) && (r1 `isSubKind` r2)
 isSubKind (PredTy (EqPred ty1 ty2)) (PredTy (EqPred ty1' ty2')) 
   = ty1 `tcEqType` ty1' && ty2 `tcEqType` ty2'
@@ -1468,14 +1465,6 @@ defaultKind k
   | isSubArgTypeKind k  = liftedTypeKind
   | otherwise        = k
 
-isCoercionKind :: Kind -> Bool
--- All coercions are of form (ty1 :=: ty2)
--- This function is here rather than in Coercion, 
--- because it's used by substTy
-isCoercionKind k | Just k' <- kindView k = isCoercionKind k'
-isCoercionKind (PredTy (EqPred {}))     = True
-isCoercionKind other                    = False
-
 isEqPred :: PredType -> Bool
 isEqPred (EqPred _ _) = True
 isEqPred other       = False