[project @ 1998-07-08 15:10:53 by simonpj]

Use constr-id application when building dictionary

diff --git a/ghc/compiler/typecheck/TcInstDcls.lhs b/ghc/compiler/typecheck/TcInstDcls.lhs
index 8e8f846..18fbbc6 100644 (file)
--- a/ghc/compiler/typecheck/TcInstDcls.lhs
+++ b/ghc/compiler/typecheck/TcInstDcls.lhs
@@ -439,9 +439,15 @@ tcInstDecl2 (InstInfo clas inst_tyvars inst_tys
                  (HsLitOut (HsString msg) stringTy)
 
          | otherwise   -- The common case
-         = HsCon dict_constr inst_tys' (map HsVar (sc_dict_ids ++ meth_ids))
+         = foldl HsApp (TyApp (HsVar (RealId dict_constr)) inst_tys')
+                              (map HsVar (sc_dict_ids ++ meth_ids))
                -- We don't produce a binding for the dict_constr; instead we
-               -- just generate the saturated constructor directly
+               -- rely on the simplifier to unfold this saturated application
+               -- We do this rather than generate an HsCon directly, because
+               -- it means that the special cases (e.g. dictionary with only one
+               -- member) are dealt with by the common MkId.mkDataConId code rather
+               -- than needing to be repeated here.
+
          where
            msg = _PK_ ("Compiler error: bad dictionary " ++ showSDoc (ppr clas))