Monadify specialise/Specialise: use do, return, standard monad functions and MonadUnique

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

diff --git a/compiler/typecheck/TcClassDcl.lhs b/compiler/typecheck/TcClassDcl.lhs
index 7f66273..2e7603b 100644 (file)
--- a/compiler/typecheck/TcClassDcl.lhs
+++ b/compiler/typecheck/TcClassDcl.lhs
@@ -6,11 +6,11 @@
 Typechecking class declarations
 
 \begin{code}
-{-# OPTIONS_GHC -w #-}
+{-# OPTIONS -w #-}
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
 -- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/WorkingConventions#Warnings
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
 module TcClassDcl ( tcClassSigs, tcClassDecl2, 
@@ -60,6 +60,8 @@ import List
 import BasicTypes
 import Bag
 import FastString
+
+import Control.Monad
 \end{code}
 
 
@@ -552,7 +554,7 @@ isInstDecl (SigOrigin (ClsSkol _)) = False
 -- The renamer just puts the selector ID as the binder in the method binding
 -- but we must use the method name; so we substitute it here.  Crude but simple.
 find_bind sel_name meth_name binds
-  = foldlBag seqMaybe Nothing (mapBag f binds)
+  = foldlBag mplus Nothing (mapBag f binds)
   where 
        f (L loc1 bind@(FunBind { fun_id = L loc2 op_name })) | op_name == sel_name
                 = Just (L loc1 (bind { fun_id = L loc2 meth_name }))