Properly ppr InstEqs in wanteds of implication constraints

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

diff --git a/compiler/typecheck/Inst.lhs b/compiler/typecheck/Inst.lhs
index fac10ab..da80df4 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"
@@ -604,11 +603,14 @@ pprInst i@(EqInst {tci_left = ty1, tci_right = ty2, tci_co = co})
                (\covar -> text "Wanted" <+> ppr (TyVarTy covar) <+> dcolon <+> ppr (EqPred ty1 ty2))
                (\co    -> text "Given"  <+> ppr co              <+> dcolon <+> ppr (EqPred ty1 ty2))
 pprInst inst = ppr (instName inst) <+> dcolon 
-               <+> (braces (ppr (instType inst)) $$
+               <+> (braces (ppr (instType inst) <> implicWantedEqs) $$
                     ifPprDebug implic_stuff)
   where
-    implic_stuff | isImplicInst inst = ppr (tci_reft inst)
-                | otherwise         = empty
+    (implic_stuff, implicWantedEqs) 
+      | isImplicInst inst = (ppr (tci_reft inst),
+                            text " &" <+> 
+                            ppr (filter isEqInst (tci_wanted inst)))
+      | otherwise        = (empty, empty)
 
 pprInstInFull inst@(EqInst {}) = pprInst inst
 pprInstInFull inst = sep [quotes (pprInst inst), nest 2 (pprInstArising inst)]
@@ -1052,9 +1054,8 @@ 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}