Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : ghc-7.6
http://hackage.haskell.org/trac/ghc/changeset/1b6815c6ff197667af49c89edd2cf43af5276aa9 >--------------------------------------------------------------- commit 1b6815c6ff197667af49c89edd2cf43af5276aa9 Author: Simon Peyton Jones <[email protected]> Date: Sun Sep 9 07:07:39 2012 +0100 Remember to zonk the skolems of an implication Their kinds may contain kind unification variables! This patch fixes Trac #7230. >--------------------------------------------------------------- compiler/typecheck/TcMType.lhs | 25 ++++++++++++++++++------- 1 files changed, 18 insertions(+), 7 deletions(-) diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs index 411d85a..67ed967 100644 --- a/compiler/typecheck/TcMType.lhs +++ b/compiler/typecheck/TcMType.lhs @@ -593,14 +593,17 @@ skolemiseSigTv tv \begin{code} zonkImplication :: Implication -> TcM Implication -zonkImplication implic@(Implic { ic_given = given +zonkImplication implic@(Implic { ic_skols = skols + , ic_given = given , ic_wanted = wanted , ic_loc = loc }) - = do { -- No need to zonk the skolems + = do { skols' <- mapM zonkTcTyVarBndr skols -- Need to zonk their kinds! + -- as Trac #7230 showed ; given' <- mapM zonkEvVar given ; loc' <- zonkGivenLoc loc ; wanted' <- zonkWC wanted - ; return (implic { ic_given = given' + ; return (implic { ic_skols = skols' + , ic_given = given' , ic_wanted = wanted' , ic_loc = loc' }) } @@ -765,10 +768,18 @@ zonkTcType ty | otherwise = TyVarTy <$> updateTyVarKindM go tyvar -- Ordinary (non Tc) tyvars occur inside quantified types - go (ForAllTy tyvar ty) = ASSERT2( isImmutableTyVar tyvar, ppr tyvar ) do - ty' <- go ty - tyvar' <- updateTyVarKindM go tyvar - return (ForAllTy tyvar' ty') + go (ForAllTy tv ty) = do { tv' <- zonkTcTyVarBndr tv + ; ty' <- go ty + ; return (ForAllTy tv' ty') } + +zonkTcTyVarBndr :: TcTyVar -> TcM TcTyVar +-- A tyvar binder is never a unification variable (MetaTv), +-- rather it is always a skolems. BUT it may have a kind +-- that has not yet been zonked, and may include kind +-- unification variables. +zonkTcTyVarBndr tyvar + = ASSERT2( isImmutableTyVar tyvar, ppr tyvar ) do + updateTyVarKindM zonkTcType tyvar zonkTcTyVar :: TcTyVar -> TcM TcType -- Simply look through all Flexis _______________________________________________ Cvs-ghc mailing list [email protected] http://www.haskell.org/mailman/listinfo/cvs-ghc
