X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Futils%2FUtil.lhs;h=6463c1ac42f8c1692b1bc77f235ebad13d1d5330;hp=3eff34b3d53824800da7fe69a8d9f9067944c511;hb=84923cc7de2a93c22a2f72daf9ac863959efae13;hpb=046ee54f048ddd721dcee41916d6a6f68db3b15b

diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 3eff34b..6463c1a 100644
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -12,7 +12,7 @@ module Util (
         zipLazy, stretchZipWith,
 	mapFst, mapSnd,
 	mapAndUnzip, mapAndUnzip3,
-	nOfThem, filterOut,
+	nOfThem, filterOut, partitionWith, splitEithers,
 
 	lengthExceeds, lengthIs, lengthAtLeast, 
 	listLengthCmp, atLength, equalLength, compareLength,
@@ -168,6 +168,22 @@ filterOut :: (a->Bool) -> [a] -> [a]
 filterOut p [] = []
 filterOut p (x:xs) | p x       = filterOut p xs
 		   | otherwise = x : filterOut p xs
+
+partitionWith :: (a -> Either b c) -> [a] -> ([b], [c])
+partitionWith f [] = ([],[])
+partitionWith f (x:xs) = case f x of
+			   Left  b -> (b:bs, cs)
+			   Right c -> (bs, c:cs)
+		       where
+			 (bs,cs) = partitionWith f xs
+
+splitEithers :: [Either a b] -> ([a], [b])
+splitEithers [] = ([],[])
+splitEithers (e : es) = case e of
+			  Left x -> (x:xs, ys)
+			  Right y -> (xs, y:ys)
+		      where
+			(xs,ys) = splitEithers es
 \end{code}
 
 A paranoid @zip@ (and some @zipWith@ friends) that checks the lists