X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FType.lhs;h=eeacb1a575db604a5150cd009038eeb8cadb89ee;hb=ac704fcac946590eef0ec91ae19f3b47d779a75f;hp=c3013ab5b3a12e7403912adc44c710d1d221a3de;hpb=a4c34367ce3e836f52f0ffb1e379ce81b8d65316;p=ghc-hetmet.git

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index c3013ab..eeacb1a 100644
--- 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 (
@@ -12,7 +13,7 @@ module Type (
 
 	-- Kinds
         Kind, SimpleKind, KindVar,
-        kindFunResult, splitKindFunTys, 
+        kindFunResult, splitKindFunTys, splitKindFunTysN,
 
         liftedTypeKindTyCon, openTypeKindTyCon, unliftedTypeKindTyCon,
         argTypeKindTyCon, ubxTupleKindTyCon,
@@ -24,7 +25,7 @@ module Type (
 
         isLiftedTypeKind, isUnliftedTypeKind, isOpenTypeKind,
         isUbxTupleKind, isArgTypeKind, isKind, isTySuperKind, 
-        isCoSuperKind, isSuperKind, isCoercionKind,
+        isCoSuperKind, isSuperKind, isCoercionKind, isEqPred,
 	mkArrowKind, mkArrowKinds,
 
         isSubArgTypeKind, isSubOpenTypeKind, isSubKind, defaultKind, eqKind,
@@ -105,31 +106,23 @@ module Type (
 import TypeRep
 
 -- friends:
-import Var	( Var, TyVar, tyVarKind, tyVarName, 
-		  setTyVarName, setTyVarKind )
+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}
 
 
@@ -164,7 +157,9 @@ coreView :: Type -> Maybe Type
 -- By being non-recursive and inlined, this case analysis gets efficiently
 -- joined onto the case analysis that the caller is already doing
 coreView (NoteTy _ ty) 	   = Just ty
-coreView (PredTy p)    	   = Just (predTypeRep p)
+coreView (PredTy p)
+  | isEqPred p             = Nothing
+  | otherwise    	   = Just (predTypeRep p)
 coreView (TyConApp tc tys) | Just (tenv, rhs, tys') <- coreExpandTyCon_maybe tc tys 
 			   = Just (mkAppTys (substTy (mkTopTvSubst tenv) rhs) tys')
 				-- Its important to use mkAppTys, rather than (foldl AppTy),
@@ -305,10 +300,11 @@ splitAppTys ty = split ty ty []
 
 \begin{code}
 mkFunTy :: Type -> Type -> Type
+mkFunTy (PredTy (EqPred ty1 ty2)) res = mkForAllTy (mkWildCoVar (PredTy (EqPred ty1 ty2))) res
 mkFunTy arg res = FunTy arg res
 
 mkFunTys :: [Type] -> Type -> Type
-mkFunTys tys ty = foldr FunTy ty tys
+mkFunTys tys ty = foldr mkFunTy ty tys
 
 isFunTy :: Type -> Bool 
 isFunTy ty = isJust (splitFunTy_maybe ty)
@@ -445,7 +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}
@@ -454,7 +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 *
@@ -596,6 +592,7 @@ predTypeRep (IParam _ ty)     = ty
 predTypeRep (ClassP clas tys) = mkTyConApp (classTyCon clas) tys
 	-- Result might be a newtype application, but the consumer will
 	-- look through that too if necessary
+predTypeRep (EqPred ty1 ty2) = pprPanic "predTypeRep" (ppr (EqPred ty1 ty2))
 \end{code}
 
 
@@ -612,7 +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
@@ -1023,8 +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, 
@@ -1287,7 +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}
 
 ----------------------------------------------------
@@ -1366,6 +1368,9 @@ kindFunResult k = funResultTy k
 splitKindFunTys :: Kind -> ([Kind],Kind)
 splitKindFunTys k = splitFunTys k
 
+splitKindFunTysN :: Int -> Kind -> ([Kind],Kind)
+splitKindFunTysN k = splitFunTysN k
+
 isUbxTupleKind, isOpenTypeKind, isArgTypeKind, isUnliftedTypeKind :: Kind -> Bool
 
 isOpenTypeKindCon tc    = tyConUnique tc == openTypeKindTyConKey
@@ -1421,8 +1426,10 @@ 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'
 isSubKind k1 		k2 		      = False
 
 eqKind :: Kind -> Kind -> Bool
@@ -1458,11 +1465,7 @@ 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
 \end{code}