From: sof <unknown>
Date: Mon, 24 Nov 1997 21:06:11 +0000 (+0000)
Subject: [project @ 1997-11-24 21:06:11 by sof]
X-Git-Tag: Approx_2487_patches~1259
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=752fd59c1803419f4919365504065d3688b0d1ab;p=ghc-hetmet.git

[project @ 1997-11-24 21:06:11 by sof]
Have conflictFM return Maybe type rather than list
---

diff --git a/ghc/compiler/rename/RnEnv.lhs b/ghc/compiler/rename/RnEnv.lhs
index 5403354..577b795 100644
--- a/ghc/compiler/rename/RnEnv.lhs
+++ b/ghc/compiler/rename/RnEnv.lhs
@@ -529,11 +529,11 @@ conflictsFM bad fm1 fm2
 conflictFM :: Ord a 
 	   => (b->b->Bool)
 	   -> FiniteMap a b -> a -> b
-	   -> [(a,(b,b))]
+	   -> Maybe (a,(b,b))
 conflictFM bad fm key elt
   = case lookupFM fm key of
-	Just elt' | bad elt elt' -> [(key,(elt,elt'))]
-	other			 -> []
+	Just elt' | bad elt elt' -> Just (key,(elt,elt'))
+	other			 -> Nothing
 \end{code}