From 30455b14d7bf84af35ff8228c25393e12eeb93a0 Mon Sep 17 00:00:00 2001
From: Jose Pedro Magalhaes <jpm@cs.ox.ac.uk>
Date: Wed, 6 Mar 2013 09:15:37 +0000
Subject: [PATCH] some fixes
---
compiler/typecheck/TcDeriv.lhs | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs
index ce4e9957df9..5b7ecfd7b43 100644
--- a/compiler/typecheck/TcDeriv.lhs
+++ b/compiler/typecheck/TcDeriv.lhs
@@ -583,11 +583,10 @@ deriveTyData tvs tc tc_args (L loc deriv_pred)
-- newtype deriving we allow deriving (forall a. C [a]).
-- Typeable is special
- ; pprTrace "tvs, deriv_tvs, cls_tys, tc, tc_args" (ppr (tvs, deriv_tvs, cls_tys, tc, tc_args))
- $ if className cls == typeableClassName
+ ; if className cls == typeableClassName
then mkEqnHelp DerivOrigin
- tvs
- cls cls_tys (mkTyConApp tc tc_args) Nothing
+ tvs cls cls_tys
+ (mkTyConApp tc (kindVarsOnly tc_args)) Nothing
else do {
-- Given data T a b c = ... deriving( C d ),
@@ -628,6 +627,12 @@ deriveTyData tvs tc tc_args (L loc deriv_pred)
(typeFamilyPapErr tc cls cls_tys inst_ty)
; mkEqnHelp DerivOrigin (varSetElemsKvsFirst univ_tvs) cls cls_tys inst_ty Nothing } }
+ where
+ kindVarsOnly :: [Type] -> [Type]
+ kindVarsOnly [] = []
+ kindVarsOnly (t:ts) | Just v <- getTyVar_maybe t
+ , isKindVar v = t : kindVarsOnly ts
+ | otherwise = kindVarsOnly ts
\end{code}
Note [Deriving, type families, and partial applications]
@@ -812,8 +817,7 @@ mkPolyKindedTypeableEqn :: CtOrigin -> [TyVar] -> Class -> [TcType]
mkPolyKindedTypeableEqn orig tvs cls cls_tys tycon tc_args mtheta
-- The kind-polymorphic Typeable class is less special; namely, there is no
-- need to select the class with the right kind anymore, as we only have one.
- = do { pprTrace "tvs, tycon, tc_args" (ppr (tvs, tycon, tc_args))
- $ checkTc (onlyKindVars tc_args)
+ = do { checkTc (onlyKindVars tc_args)
(ptext (sLit "Derived typeable instance must be of form (Typeable")
<+> ppr tycon <> rparen)
; dfun_name <- new_dfun_name cls tycon
--
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