[project @ 2001-06-25 08:09:57 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcIfaceSig.lhs

diff --git a/ghc/compiler/typecheck/TcIfaceSig.lhs b/ghc/compiler/typecheck/TcIfaceSig.lhs
index f710e45..ad444e5 100644 (file)
--- a/ghc/compiler/typecheck/TcIfaceSig.lhs
+++ b/ghc/compiler/typecheck/TcIfaceSig.lhs
@@ -29,8 +29,9 @@ import Id             ( Id, mkVanillaGlobal, mkLocalId, idName, isDataConWrapId_maybe )
 import Module          ( Module )
 import MkId            ( mkFCallId )
 import IdInfo
+import TyCon           ( tyConDataCons )
 import DataCon         ( DataCon, dataConId, dataConSig, dataConArgTys )
-import Type            ( mkTyVarTys, splitAlgTyConApp_maybe )
+import Type            ( mkTyVarTys, splitTyConApp )
 import TysWiredIn      ( tupleCon )
 import Var             ( mkTyVar, tyVarKind )
 import Name            ( Name, nameIsLocalOrFrom )
@@ -339,9 +340,8 @@ tcCoreAlt scrut_ty alt@(con, names, rhs)
     let
        (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
 
-       (_, inst_tys, cons) = case splitAlgTyConApp_maybe scrut_ty of
-                                   Just stuff -> stuff
-                                   Nothing -> pprPanic "tcCoreAlt" (ppr alt)
+       (tycon, inst_tys)   = splitTyConApp scrut_ty    -- NB: not tcSplitTyConApp
+                                                       -- We are looking at Core here
        ex_tyvars'          = [mkTyVar name (tyVarKind tv) | (name,tv) <- names `zip` ex_tyvars] 
        ex_tys'             = mkTyVarTys ex_tyvars'
        arg_tys             = dataConArgTys con (inst_tys ++ ex_tys')
@@ -356,7 +356,7 @@ tcCoreAlt scrut_ty alt@(con, names, rhs)
 #endif
                = zipWithEqual "tcCoreAlts" mkLocalId id_names arg_tys
     in
-    ASSERT( con `elem` cons && length inst_tys == length main_tyvars )
+    ASSERT( con `elem` tyConDataCons tycon && length inst_tys == length main_tyvars )
     tcExtendTyVarEnv ex_tyvars'                        $
     tcExtendGlobalValEnv arg_ids               $
     tcCoreExpr rhs                                     `thenTc` \ rhs' ->