Introducing a datatype for WorkLists that properly prioritizes equalities.

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

diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs
index b68fee5..7453334 100644 (file)
--- a/compiler/typecheck/TcMType.lhs
+++ b/compiler/typecheck/TcMType.lhs
@@ -26,7 +26,7 @@ module TcMType (
   --------------------------------
   -- Creating new evidence variables
   newEvVar, newCoVar, newEvVars,
-  newWantedCoVar, writeWantedCoVar, readWantedCoVar, 
+  writeWantedCoVar, readWantedCoVar, 
   newIP, newDict, newSilentGiven, isSilentEvVar,
 
   newWantedEvVar, newWantedEvVars,
@@ -129,16 +129,13 @@ newEvVars :: TcThetaType -> TcM [EvVar]
 newEvVars theta = mapM newEvVar theta
 
 newWantedEvVar :: TcPredType -> TcM EvVar 
-newWantedEvVar (EqPred ty1 ty2) = newWantedCoVar ty1 ty2
+newWantedEvVar (EqPred ty1 ty2) = newCoVar ty1 ty2
 newWantedEvVar (ClassP cls tys) = newDict cls tys
 newWantedEvVar (IParam ip ty)   = newIP ip ty
 
 newWantedEvVars :: TcThetaType -> TcM [EvVar] 
 newWantedEvVars theta = mapM newWantedEvVar theta 
 
-newWantedCoVar :: TcType -> TcType -> TcM CoVar 
-newWantedCoVar ty1 ty2 = newCoVar ty1 ty2
-
 --------------
 newEvVar :: TcPredType -> TcM EvVar
 -- Creates new *rigid* variables for predicates
@@ -367,8 +364,8 @@ writeMetaTyVarRef tyvar ref ty
 
   | otherwise
   = do { meta_details <- readMutVar ref; 
-       ; WARN( not (isFlexi meta_details), 
-                hang (text "Double update of meta tyvar")
+       ; ASSERT2( isFlexi meta_details, 
+                  hang (text "Double update of meta tyvar")
                    2 (ppr tyvar $$ ppr meta_details) )
 
          traceTc "writeMetaTyVar" (ppr tyvar <+> text ":=" <+> ppr ty)