[project @ 2001-10-25 02:13:10 by sof]

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

diff --git a/ghc/compiler/typecheck/TcBinds.lhs b/ghc/compiler/typecheck/TcBinds.lhs
index e5a83ab..6c0ec03 100644 (file)
--- a/ghc/compiler/typecheck/TcBinds.lhs
+++ b/ghc/compiler/typecheck/TcBinds.lhs
@@ -50,7 +50,7 @@ import NameSet
 import Var             ( tyVarKind )
 import VarSet
 import Bag
-import Util            ( isIn )
+import Util            ( isIn, equalLength )
 import BasicTypes      ( TopLevelFlag(..), RecFlag(..), isNonRec, isNotTopLevel,
                          isAlwaysActive )
 import FiniteMap       ( listToFM, lookupFM )
@@ -471,12 +471,11 @@ checkSigsCtxts sigs@(TySigInfo _ id1 sig_tvs theta1 _ _ _ src_loc : other_sigs)
     returnTc (sig_avails, map instToId sig_dicts)
   where
     sig1_dict_tys = map mkPredTy theta1
-    n_sig1_theta  = length theta1
     sig_meths    = concat [insts | TySigInfo _ _ _ _ _ _ insts _ <- sigs]
 
     check_one sig@(TySigInfo _ id _ theta _ _ _ src_loc)
        = tcAddErrCtxt (sigContextsCtxt id1 id)                 $
-        checkTc (length theta == n_sig1_theta) sigContextsErr  `thenTc_`
+        checkTc (equalLength theta theta1) sigContextsErr      `thenTc_`
         unifyTauTyLists sig1_dict_tys (map mkPredTy theta)
 
 checkSigsTyVars sigs = mapTc_ check_one sigs