X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FFamInstEnv.lhs;h=60b55d10ce08c6c7b90b814062b3c9f6d51f0cff;hb=cd290fc88d35d5a32c994664baa56a5eae250e9e;hp=9b49f5c34393fb9ac329bd4620894c90678cd6be;hpb=8a5d47de2b82d9cca86546a7bd89d915488934ef;p=ghc-hetmet.git

diff --git a/compiler/types/FamInstEnv.lhs b/compiler/types/FamInstEnv.lhs
index 9b49f5c..60b55d1 100644
--- a/compiler/types/FamInstEnv.lhs
+++ b/compiler/types/FamInstEnv.lhs
@@ -6,10 +6,12 @@ FamInstEnv: Type checked family instance declarations
 
 \begin{code}
 module FamInstEnv (
-	FamInst(..), famInstTyCon, pprFamInst, pprFamInstHdr, pprFamInsts, 
+	FamInst(..), famInstTyCon, famInstTyVars, 
+	pprFamInst, pprFamInstHdr, pprFamInsts, 
 	famInstHead, mkLocalFamInst, mkImportedFamInst,
 
-	FamInstEnv, emptyFamInstEnv, extendFamInstEnv, extendFamInstEnvList, 
+	FamInstEnvs, FamInstEnv, emptyFamInstEnv, 
+	extendFamInstEnv, extendFamInstEnvList, 
 	famInstEnvElts, familyInstances,
 
 	lookupFamInstEnv, lookupFamInstEnvUnify
@@ -32,7 +34,6 @@ import UniqFM
 import Outputable
 
 import Maybe
-import Monad
 \end{code}
 
 
@@ -45,13 +46,19 @@ import Monad
 \begin{code}
 data FamInst 
   = FamInst { fi_fam   :: Name		-- Family name
+		-- INVARIANT: fi_fam = case tyConFamInst_maybe fi_tycon of
+		--			   Just (tc, tys) -> tc
 
 		-- Used for "rough matching"; same idea as for class instances
 	    , fi_tcs   :: [Maybe Name]	-- Top of type args
+		-- INVARIANT: fi_tcs = roughMatchTcs is_tys
 
 		-- Used for "proper matching"; ditto
 	    , fi_tvs   :: TyVarSet	-- Template tyvars for full match
 	    , fi_tys   :: [Type]	-- Full arg types
+		-- INVARIANT: fi_tvs = tyConTyVars fi_tycon
+		--	      fi_tys = case tyConFamInst_maybe fi_tycon of
+		--			   Just (_, tys) -> tys
 
 	    , fi_tycon :: TyCon		-- Representation tycon
 	    }
@@ -60,6 +67,8 @@ data FamInst
 --
 famInstTyCon :: FamInst -> TyCon
 famInstTyCon = fi_tycon
+
+famInstTyVars = fi_tvs
 \end{code}
 
 \begin{code}
@@ -79,8 +88,7 @@ pprFamInstHdr :: FamInst -> SDoc
 pprFamInstHdr (FamInst {fi_fam = fam, fi_tys = tys, fi_tycon = tycon})
   = pprTyConSort <+> pprHead
   where
-    pprHead = parenSymOcc (getOccName fam) (ppr fam) <+> 
-	      sep (map pprParendType tys)
+    pprHead = pprTypeApp (parenSymOcc (getOccName fam) (ppr fam)) tys
     pprTyConSort | isDataTyCon tycon = ptext SLIT("data instance")
 		 | isNewTyCon  tycon = ptext SLIT("newtype instance")
 		 | isSynTyCon  tycon = ptext SLIT("type instance")
@@ -140,6 +148,9 @@ InstEnv maps a family name to the list of known instances for that family.
 \begin{code}
 type FamInstEnv = UniqFM FamilyInstEnv	-- Maps a family to its instances
 
+type FamInstEnvs = (FamInstEnv, FamInstEnv)
+ 	-- External package inst-env, Home-package inst-env
+
 data FamilyInstEnv
   = FamIE [FamInst]	-- The instances for a particular family, in any order
   	  Bool 		-- True <=> there is an instance of form T a b c
@@ -174,7 +185,7 @@ extendFamInstEnv inst_env ins_item@(FamInst {fi_fam = cls_nm, fi_tcs = mb_tcs})
     add (FamIE items tyvar) _ = FamIE (ins_item:items)
 				      (ins_tyvar || tyvar)
     ins_tyvar = not (any isJust mb_tcs)
-\end{code}		      
+\end{code}
 
 %************************************************************************
 %*									*
@@ -188,8 +199,7 @@ families), and then, it doesn't matter which match we choose (as the
 instances are guaranteed confluent).
 
 \begin{code}
-lookupFamInstEnv :: (FamInstEnv 	-- External package inst-env
-		    ,FamInstEnv) 	-- Home-package inst-env
+lookupFamInstEnv :: FamInstEnvs
 	         -> TyCon -> [Type]		-- What we are looking for
 	         -> [(TvSubst, FamInst)] 	-- Successful matches
 lookupFamInstEnv (pkg_ie, home_ie) fam tys