From: Manuel M T Chakravarty <chak@cse.unsw.edu.au>
Date: Sun, 6 Aug 2006 21:20:26 +0000 (+0000)
Subject: GADT fixes
X-Git-Tag: After_FC_branch_merge~146
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=df540a334232b9f2da702e48e1ebaf4b289997bc

GADT fixes
Wed Jul 26 06:00:53 EDT 2006  kevind@bu.edu
---

diff --git a/compiler/hsSyn/HsUtils.lhs b/compiler/hsSyn/HsUtils.lhs
index d9c45e6..50d12a3 100644
--- a/compiler/hsSyn/HsUtils.lhs
+++ b/compiler/hsSyn/HsUtils.lhs
@@ -397,6 +397,7 @@ collectl (L l pat) bndrs
     go (TypePat ty)               = bndrs
     go (DictPat ids1 ids2)        = map noLoc ids1 ++ map noLoc ids2
 				    ++ bndrs
+    go (CoPat _ pat ty)           = collectl (noLoc pat) bndrs
 \end{code}
 
 \begin{code}
diff --git a/compiler/types/FunDeps.lhs b/compiler/types/FunDeps.lhs
index 1534dc6..0d7eb24 100644
--- a/compiler/types/FunDeps.lhs
+++ b/compiler/types/FunDeps.lhs
@@ -1,4 +1,4 @@
-%
+
 % (c) The GRASP/AQUA Project, Glasgow University, 2000
 %
 \section[FunDeps]{FunDeps - functional dependencies}
@@ -20,6 +20,7 @@ import Var		( TyVar )
 import Class		( Class, FunDep, pprFundeps, classTvsFds )
 import TcGadt		( tcUnifyTys, BindFlag(..) )
 import Type		( substTys, notElemTvSubst )
+import Coercion         ( isEqPred )
 import TcType		( Type, PredType(..), tcEqType, 
 			  predTyUnique, mkClassPred, tyVarsOfTypes, tyVarsOfPred )
 import InstEnv		( Instance(..), InstEnv, instanceHead, classInstances,
@@ -219,8 +220,9 @@ NOTA BENE:
 
 \begin{code}
 improve inst_env preds
-  = [ eqn | group <- equivClassesByUniq (predTyUnique . fst) preds,
+  = [ eqn | group <- equivClassesByUniq (predTyUnique . fst) (filterEqPreds preds),
 	    eqn   <- checkGroup inst_env group ]
+  where filterEqPreds = filter (not . isEqPred . fst)
 
 ----------
 checkGroup :: (Class -> [Instance])