Merge branch 'ghc-generics' of http://darcs.haskell.org/ghc into ghc-generics

diff --combined compiler/typecheck/TcDeriv.lhs
index 5bbb382,3bb46ed..5d292fd
--- 1/compiler/typecheck/TcDeriv.lhs
--- 2/compiler/typecheck/TcDeriv.lhs
+++ b/compiler/typecheck/TcDeriv.lhs
@@@ -407,7 -407,7 +407,7 @@@ renameDeriv is_boot gen_binds inst
                -- scope (yuk), and rename the method binds
           ASSERT( null sigs )
           bindLocalNames (map Var.varName tyvars) $
-          do { (rn_binds, fvs) <- rnMethodBinds clas_nm (\_ -> []) [] binds
+          do { (rn_binds, fvs) <- rnMethodBinds clas_nm (\_ -> []) binds
              ; let binds' = VanillaInst rn_binds [] standalone_deriv
                ; return (inst_info { iBinds = binds' }, fvs) }
        where
@@@ -986,11 -986,11 +986,11 @@@ cond_stdOK Nothing (_, rep_tc
      check_con con 
        | isVanillaDataCon con
        , all isTauTy (dataConOrigArgTys con) = Nothing
 -      | otherwise = Just (badCon con (ptext (sLit "does not have a Haskell-98 type")))
 +      | otherwise = Just (badCon con (ptext (sLit "must have a Haskell-98 type")))
    
  no_cons_why :: TyCon -> SDoc
  no_cons_why rep_tc = quotes (pprSourceTyCon rep_tc) <+> 
 -                   ptext (sLit "has no data constructors")
 +                   ptext (sLit "must have at least one data constructor")
  
  -- JPM TODO: should give better error message
  cond_RepresentableOk :: Condition
@@@ -1010,7 -1010,7 +1010,7 @@@ cond_noUnliftedArgs (_, tc
    where
      bad_cons = [ con | con <- tyConDataCons tc
                     , any isUnLiftedType (dataConOrigArgTys con) ]
 -    why = badCon (head bad_cons) (ptext (sLit "has arguments of unlifted type"))
 +    why = badCon (head bad_cons) (ptext (sLit "must have only arguments of lifted type"))
  
  cond_isEnumeration :: Condition
  cond_isEnumeration (_, rep_tc)
@@@ -1018,7 -1018,7 +1018,7 @@@
    | otherwise                 = Just why
    where
      why = sep [ quotes (pprSourceTyCon rep_tc) <+> 
 -                ptext (sLit "is not an enumeration type")
 +                ptext (sLit "must be an enumeration type")
                , ptext (sLit "(an enumeration consists of one or more nullary, non-GADT constructors)") ]
                  -- See Note [Enumeration types] in TyCon
  
@@@ -1028,7 -1028,7 +1028,7 @@@ cond_isProduct (_, rep_tc
    | otherwise           = Just why
    where
      why = quotes (pprSourceTyCon rep_tc) <+> 
 -        ptext (sLit "does not have precisely one constructor")
 +        ptext (sLit "must have precisely one constructor")
  
  cond_typeableOK :: Condition
  -- OK for Typeable class
@@@ -1041,9 -1041,9 +1041,9 @@@ cond_typeableOK (_, tc
    | otherwise       = Nothing
    where
      too_many = quotes (pprSourceTyCon tc) <+> 
 -             ptext (sLit "has too many arguments")
 +             ptext (sLit "must have 7 or fewer arguments")
      bad_kind = quotes (pprSourceTyCon tc) <+> 
 -             ptext (sLit "has arguments of kind other than `*'")
 +             ptext (sLit "must only have arguments of kind `*'")
  
  functorLikeClassKeys :: [Unique]
  functorLikeClassKeys = [functorClassKey, foldableClassKey, traversableClassKey]
@@@ -1058,11 -1058,11 +1058,11 @@@ cond_functorOK :: Bool -> Conditio
  cond_functorOK allowFunctions (_, rep_tc)
    | null tc_tvs
    = Just (ptext (sLit "Data type") <+> quotes (ppr rep_tc) 
 -          <+> ptext (sLit "has no parameters"))
 +          <+> ptext (sLit "must have some type parameters"))
  
    | not (null bad_stupid_theta)
    = Just (ptext (sLit "Data type") <+> quotes (ppr rep_tc) 
 -          <+> ptext (sLit "has a class context") <+> pprTheta bad_stupid_theta)
 +          <+> ptext (sLit "must not have a class context") <+> pprTheta bad_stupid_theta)
  
    | otherwise
    = msum (map check_con data_cons)    -- msum picks the first 'Just', if any
@@@ -1089,10 -1089,10 +1089,10 @@@
                        , ft_bad_app = Just (badCon con wrong_arg)
                        , ft_forall = \_ x   -> x }
                      
 -    existential = ptext (sLit "has existential arguments")
 -    covariant         = ptext (sLit "uses the type variable in a function argument")
 -    functions         = ptext (sLit "contains function types")
 -    wrong_arg         = ptext (sLit "uses the type variable in an argument other than the last")
 +    existential = ptext (sLit "must not have existential arguments")
 +    covariant         = ptext (sLit "must not use the type variable in a function argument")
 +    functions         = ptext (sLit "must not contain function types")
 +    wrong_arg         = ptext (sLit "must not use the type variable in an argument other than the last")
  
  checkFlag :: ExtensionFlag -> Condition
  checkFlag flag (dflags, _)