Improve the error message when we cannot derive Generic.

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

diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs
index 4d80631..a3ce1a9 100644 (file)
--- a/compiler/typecheck/TcDeriv.lhs
+++ b/compiler/typecheck/TcDeriv.lhs
@@ -993,8 +993,11 @@ no_cons_why rep_tc = quotes (pprSourceTyCon rep_tc) <+>
 
 -- JPM TODO: should give better error message
 cond_RepresentableOk :: Condition
+{-
 cond_RepresentableOk (_,t) | canDoGenerics t = Nothing
                            | otherwise       = Just (ptext (sLit "Cannot derive Generic for type") <+> ppr t)
+-}
+cond_RepresentableOk (_,t) = canDoGenerics t
 
 cond_enumOrProduct :: Condition
 cond_enumOrProduct = cond_isEnumeration `orCond`