X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FInst.lhs;h=d75a7cd290c59c0252668d98d4638fbe06c35e27;hb=3f1b316d7035c55cd712cd39a9981339bcef2e8c;hp=1032f91c60acd8f85bd7623b3f3abc9243fdcffe;hpb=6a05ec5ef5373f61b7f9f5bdc344483417fa801b;p=ghc-hetmet.git

diff --git a/compiler/typecheck/Inst.lhs b/compiler/typecheck/Inst.lhs
index 1032f91..d75a7cd 100644
--- a/compiler/typecheck/Inst.lhs
+++ b/compiler/typecheck/Inst.lhs
@@ -52,8 +52,7 @@ module Inst (
 	eitherEqInst, mkEqInst, mkEqInsts, mkWantedEqInst,
 	finalizeEqInst, writeWantedCoercion,
 	eqInstType, updateEqInstCoercion,
-	eqInstCoercion,
-	eqInstLeftTy, eqInstRightTy
+	eqInstCoercion,	eqInstTys
     ) where
 
 #include "HsVersions.h"
@@ -99,6 +98,8 @@ import Outputable
 import Data.List
 import TypeRep
 import Class
+
+import Control.Monad ( liftM )
 \end{code}
 
 
@@ -139,7 +140,7 @@ instType imp@(ImplicInst {})      = mkImplicTy (tci_tyvars imp) (tci_given imp)
 instType (EqInst {tci_left = ty1, tci_right = ty2}) = mkPredTy (EqPred ty1 ty2)
 
 mkImplicTy tvs givens wanteds	-- The type of an implication constraint
-  = ASSERT( all isDict givens )
+  = ASSERT( all isAbstractableInst givens )
     -- pprTrace "mkImplicTy" (ppr givens) $
     -- See [Equational Constraints in Implication Constraints]
     let dict_wanteds = filter (not . isEqInst) wanteds
@@ -555,11 +556,11 @@ zonkInst implic@(ImplicInst {})
 
 zonkInst eqinst@(EqInst {tci_left = ty1, tci_right = ty2})
   = do { co' <- eitherEqInst eqinst 
-			(\covar -> return (mkWantedCo covar)) 
-			(\co    -> zonkTcType co >>= \coercion -> return (mkGivenCo coercion))
+		  (\covar -> return (mkWantedCo covar)) 
+		  (\co    -> liftM mkGivenCo $ zonkTcType co)
        ; ty1' <- zonkTcType ty1
        ; ty2' <- zonkTcType ty2
-       ; return (eqinst {tci_co = co',tci_left=ty1',tci_right=ty2})
+       ; return (eqinst {tci_co = co', tci_left= ty1', tci_right = ty2' })
        }
 
 zonkInsts insts = mappM zonkInst insts
@@ -1050,9 +1051,8 @@ eqInstType inst = eitherEqInst inst mkTyVarTy id
 eqInstCoercion :: Inst -> Either TcTyVar Coercion
 eqInstCoercion = tci_co
 
-eqInstLeftTy, eqInstRightTy :: Inst -> TcType
-eqInstLeftTy  = tci_left
-eqInstRightTy = tci_right
+eqInstTys :: Inst -> (TcType, TcType)
+eqInstTys inst = (tci_left inst, tci_right inst)
 
 updateEqInstCoercion :: (Either TcTyVar Coercion -> Either TcTyVar Coercion) -> Inst -> Inst
 updateEqInstCoercion f inst = inst {tci_co = f $ tci_co inst}