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Diffstat (limited to 'utility.hs')
-rw-r--r-- | utility.hs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/utility.hs b/utility.hs new file mode 100644 index 0000000..c442f80 --- /dev/null +++ b/utility.hs @@ -0,0 +1,20 @@ +module Utility where + +import Data.List + +--if any of the predicates returns true, options returns true +options :: [a -> Bool] -> a -> Bool +options l x = any id [f x | f <- l] + +fixpoint :: (Eq a) => (a -> a) -> a -> a +fixpoint f x = let fx = f x in if fx == x then x else fixpoint f fx + +setcompareBy :: (a -> a -> Bool) -> [a] -> [a] -> Bool +setcompareBy _ [] [] = True +setcompareBy _ [] _ = False +setcompareBy _ _ [] = False +setcompareBy p a@(x:xs) b = length a == length b && setcompareBy p xs (deleteBy p x b) + +deleteIndex :: Int -> [a] -> [a] +deleteIndex 0 (_:xs) = xs +deleteIndex i (x:xs) | i > 0 = x : deleteIndex (i-1) xs |