[add union,unions, and sempty to SetLike class, remove 'Monoid' superclass
John Meacham <john@repetae.net>**20070606073202] hunk ./Util/SetLike.hs 6
-    union,
-    unions,
hunk ./Util/SetLike.hs 8
+    intersects,
hunk ./Util/SetLike.hs 29
-class (Monoid s,HasSize s,IsEmpty s) => SetLike s where
+class (HasSize s,IsEmpty s) => SetLike s where
hunk ./Util/SetLike.hs 35
+    union :: s -> s -> s
+    unions :: [s] -> s
+    sempty :: s
+
hunk ./Util/SetLike.hs 41
+    unions ss = foldr union sempty ss
hunk ./Util/SetLike.hs 64
-union :: SetLike a => a -> a -> a
-union = mappend
-
-unions :: SetLike a => [a] -> a
-unions = mconcat
+intersects x y = not $ disjoint x y
+
hunk ./Util/SetLike.hs 73
+    union      = IS.union
+    unions     = IS.unions
+    sempty      = IS.empty
hunk ./Util/SetLike.hs 94
+    union      = S.union
+    unions     = S.unions
+    sempty      = S.empty
hunk ./Util/SetLike.hs 114
+    union      = IM.union
+    unions     = IM.unions
+    sempty      = IM.empty
hunk ./Util/SetLike.hs 129
+    union      = M.union
+    unions     = M.unions
+    sempty      = M.empty