[haddock @ 2004-03-25 10:01:42 by simonmar]

Fix duplicate instance bug

1 files changed, 1 insertions, 2 deletions

diff --git a/src/Main.hs b/src/Main.hs
index bf1350ec..9106bffb 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1098,8 +1098,7 @@ collectInstances mod_ifaces
 			
     ty_inst_pairs = [ (nm, [(ctxt,(cls,args))])
 		    | HsInstDecl _ ctxt (cls,args) _ <- all_instances,
-		      arg <- args,
-		      nm <- freeTyCons arg
+		      nm <- nub (concat (map freeTyCons args))
 		    ]
  
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