X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FInst.lhs;h=66e72e4bce558929c1c146f0e235c58d92bd76c6;hp=1032f91c60acd8f85bd7623b3f3abc9243fdcffe;hb=3f1d7cd8eea305b13b39b304df23bbc680a729f0;hpb=e71c0818e3c5d7b0f8a681f887b6ee00532948a9

diff --git a/compiler/typecheck/Inst.lhs b/compiler/typecheck/Inst.lhs
index 1032f91..66e72e4 100644
--- a/compiler/typecheck/Inst.lhs
+++ b/compiler/typecheck/Inst.lhs
@@ -99,6 +99,8 @@ import Outputable
 import Data.List
 import TypeRep
 import Class
+
+import Control.Monad ( liftM )
 \end{code}
 
 
@@ -555,11 +557,11 @@ 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