Rejig the error messages a bit; fixes a minor bug

[ghc-hetmet.git] / compiler / typecheck / Inst.lhs

diff --git a/compiler/typecheck/Inst.lhs b/compiler/typecheck/Inst.lhs
index 66e72e4..d75a7cd 100644 (file)
--- 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"
@@ -141,7 +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
@@ -1052,9 +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}