Identity extension data

1 files changed, 23 insertions, 0 deletions

diff --git a/src/Util.hs b/src/Util.hs
index fe802e2..c69adee 100644
--- a/src/Util.hs
+++ b/src/Util.hs
@@ -12,3 +12,26 @@ mergeBy cmp (x : xs) (y : ys) = case cmp x y of
                                      GT -> y : mergeBy cmp (x : xs) ys
 mergeBy _ xs [] = xs
 mergeBy _ [] ys = ys
+
+mergeUniqBy :: (a -> a -> Ordering) -> [a] -> [a] -> [a]
+mergeUniqBy cmp (x : xs) (y : ys) = case cmp x y of
+                                         LT -> x : mergeBy cmp xs (y : ys)
+                                         EQ -> x : mergeBy cmp xs ys
+                                         GT -> y : mergeBy cmp (x : xs) ys
+mergeUniqBy _ xs [] = xs
+mergeUniqBy _ [] ys = ys
+
+mergeUniq :: Ord a => [a] -> [a] -> [a]
+mergeUniq = mergeUniqBy compare
+
+diffSorted :: Ord a => [a] -> [a] -> [a]
+diffSorted (x:xs) (y:ys) | x < y     = x : diffSorted xs (y:ys)
+                         | x > y     = diffSorted (x:xs) ys
+                         | otherwise = diffSorted xs (y:ys)
+diffSorted xs _ = xs
+
+intersectsSorted :: Ord a => [a] -> [a] -> Bool
+intersectsSorted (x:xs) (y:ys) | x < y     = intersectsSorted xs (y:ys)
+                               | x > y     = intersectsSorted (x:xs) ys
+                               | otherwise = True
+intersectsSorted _ _ = False