X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcType.lhs;h=c10c2eb91408b11ff542f018df2e22ac6c6e147e;hb=2fff69381d951c08a42e512722c3633d9ba556d0;hp=a53c9ed2fc9801b054a0bb645da5ef689c6a08ff;hpb=e8a591c1a3dbdeccec2dd2aacccd7435004b0d51;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcType.lhs b/compiler/typecheck/TcType.lhs
index a53c9ed..c10c2eb 100644
--- a/compiler/typecheck/TcType.lhs
+++ b/compiler/typecheck/TcType.lhs
@@ -10,7 +10,7 @@ compiler.  These parts
 		newtypes, and predicates are meaningful. 
 	* look through usage types
 
-The "tc" prefix is for "typechechecker", because the type checker
+The "tc" prefix is for "TypeChecker", because the type checker
 is the principal client.
 
 \begin{code}
@@ -344,6 +344,7 @@ data SkolemInfo
 	-- The rest are for non-scoped skolems
   | ClsSkol Class	-- Bound at a class decl
   | InstSkol Id		-- Bound at an instance decl
+  | FamInstSkol TyCon	-- Bound at a family instance decl
   | PatSkol DataCon	-- An existential type variable bound by a pattern for
 	    SrcSpan	-- a data constructor with an existential type. E.g.
 			--	data T = forall a. Eq a => MkT a
@@ -398,6 +399,7 @@ mkKindName unique = mkSystemName unique kind_var_occ
 
 kindVarRef :: KindVar -> IORef MetaDetails
 kindVarRef tc = 
+  ASSERT ( isTcTyVar tc )
   case tcTyVarDetails tc of
     MetaTv TauTv ref -> ref
     other            -> pprPanic "kindVarRef" (ppr tc)
@@ -471,7 +473,8 @@ pprSkolTvBinding :: TcTyVar -> SDoc
 -- Print info about the binding of a skolem tyvar, 
 -- or nothing if we don't have anything useful to say
 pprSkolTvBinding tv
-  = ppr_details (tcTyVarDetails tv)
+  = ASSERT ( isTcTyVar tv )
+    ppr_details (tcTyVarDetails tv)
   where
     ppr_details (MetaTv TauTv _)   = quotes (ppr tv) <+> ptext SLIT("is a meta type variable")
     ppr_details (MetaTv BoxTv _)   = quotes (ppr tv) <+> ptext SLIT("is a boxy type variable")
@@ -486,8 +489,13 @@ pprSkolTvBinding tv
 pprSkolInfo :: SkolemInfo -> SDoc
 pprSkolInfo (SigSkol ctxt)   = ptext SLIT("is bound by") <+> pprUserTypeCtxt ctxt
 pprSkolInfo (ClsSkol cls)    = ptext SLIT("is bound by the class declaration for") <+> quotes (ppr cls)
-pprSkolInfo (InstSkol df)    = ptext SLIT("is bound by the instance declaration at") <+> ppr (getSrcLoc df)
-pprSkolInfo (ArrowSkol loc)  = ptext SLIT("is bound by the arrow form at") <+> ppr loc
+pprSkolInfo (InstSkol df)    = 
+  ptext SLIT("is bound by the instance declaration at") <+> ppr (getSrcLoc df)
+pprSkolInfo (FamInstSkol tc) = 
+  ptext SLIT("is bound by the family instance declaration at") <+> 
+  ppr (getSrcLoc tc)
+pprSkolInfo (ArrowSkol loc)  = 
+  ptext SLIT("is bound by the arrow form at") <+> ppr loc
 pprSkolInfo (PatSkol dc loc) = sep [ptext SLIT("is bound by the pattern for") <+> quotes (ppr dc),
            		            nest 2 (ptext SLIT("at") <+> ppr loc)]
 pprSkolInfo (GenSkol tvs ty loc) = sep [sep [ptext SLIT("is bound by the polymorphic type"), 
@@ -704,9 +712,17 @@ tcSplitTyConApp_maybe :: Type -> Maybe (TyCon, [Type])
 tcSplitTyConApp_maybe ty | Just ty' <- tcView ty = tcSplitTyConApp_maybe ty'
 tcSplitTyConApp_maybe (TyConApp tc tys) = Just (tc, tys)
 tcSplitTyConApp_maybe (FunTy arg res)   = Just (funTyCon, [arg,res])
+tcSplitTyConApp_maybe (AppTy arg res)   = Just (funTyCon, [arg,res])
 	-- Newtypes are opaque, so they may be split
 	-- However, predicates are not treated
 	-- as tycon applications by the type checker
+
+-- XXX - 2006-09-24: This case is hard-coded in (rendering predicates opaque as well)
+--       to make the newly reworked newtype-deriving work on the trivial case:
+--              newtype T = T () deriving (Eq, Ord)
+--       Please remove this if the newtype-deriving scheme no longer produces a PredTy.
+tcSplitTyConApp_maybe (PredTy (ClassP _ [ty']))   = tcSplitTyConApp_maybe ty'
+
 tcSplitTyConApp_maybe other	      	= Nothing
 
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