X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcSMonad.lhs;h=93c795d33cbc05595c2c8e55fdddb9fdf0d174a0;hb=201145f80c2c797badceabd0287cc7f5e98302aa;hp=b105f8de7267d0b7605e06f838ba1b1eaf27412a;hpb=debb7b80e707c343a3a7d8993ffab19b83e5c52b;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcSMonad.lhs b/compiler/typecheck/TcSMonad.lhs
index b105f8d..93c795d 100644
--- a/compiler/typecheck/TcSMonad.lhs
+++ b/compiler/typecheck/TcSMonad.lhs
@@ -10,7 +10,7 @@ module TcSMonad (
     makeGivens, makeSolved,
 
     CtFlavor (..), isWanted, isGiven, isDerived, canRewrite, 
-    joinFlavors, mkGivenFlavor,
+    combineCtLoc, mkGivenFlavor,
 
     TcS, runTcS, failTcS, panicTcS, traceTcS, traceTcS0,  -- Basic functionality 
     tryTcS, nestImplicTcS, wrapErrTcS, wrapWarnTcS,
@@ -100,7 +100,6 @@ import FunDeps
 
 import TcRnTypes
 
-import Control.Monad
 import Data.IORef
 \end{code}
 
@@ -298,12 +297,13 @@ canRewrite (Derived {}) (Derived {}) = True
 canRewrite (Wanted {})  (Wanted {})  = True
 canRewrite _ _ = False
 
-joinFlavors :: CtFlavor -> CtFlavor -> CtFlavor 
-joinFlavors (Wanted loc) _  = Wanted loc 
-joinFlavors _ (Wanted loc)  = Wanted loc 
-joinFlavors (Derived loc) _ = Derived loc 
-joinFlavors _ (Derived loc) = Derived loc 
-joinFlavors (Given loc) _   = Given loc
+combineCtLoc :: CtFlavor -> CtFlavor -> WantedLoc
+-- Precondition: At least one of them should be wanted 
+combineCtLoc (Wanted loc) _ = loc 
+combineCtLoc _ (Wanted loc) = loc 
+combineCtLoc (Derived loc) _ = loc 
+combineCtLoc _ (Derived loc) = loc 
+combineCtLoc _ _ = panic "combineCtLoc: both given"
 
 mkGivenFlavor :: CtFlavor -> SkolemInfo -> CtFlavor
 mkGivenFlavor (Wanted  loc) sk = Given (setCtLocOrigin loc sk)