-- 'y' is the potential new element
elem_by :: (a -> a -> Bool) -> a -> [a] -> Bool
elem_by _ _ [] = False
-elem_by eq y (x:xs) = x `eq` y || elem_by eq y xs
+elem_by eq y (x:xs) = y `eq` x || elem_by eq y xs
#endif
-- | The 'genericTake' function is an overloaded version of 'take', which
-- accepts any 'Integral' value as the number of elements to take.
genericTake :: (Integral i) => i -> [a] -> [a]
-genericTake 0 _ = []
+genericTake n _ | n <= 0 = []
genericTake _ [] = []
-genericTake n (x:xs) | n > 0 = x : genericTake (n-1) xs
-genericTake _ _ = error "List.genericTake: negative argument"
+genericTake n (x:xs) = x : genericTake (n-1) xs
-- | The 'genericDrop' function is an overloaded version of 'drop', which
-- accepts any 'Integral' value as the number of elements to drop.
genericDrop :: (Integral i) => i -> [a] -> [a]
-genericDrop 0 xs = xs
+genericDrop n xs | n <= 0 = xs
genericDrop _ [] = []
-genericDrop n (_:xs) | n > 0 = genericDrop (n-1) xs
-genericDrop _ _ = error "List.genericDrop: negative argument"
+genericDrop n (_:xs) = genericDrop (n-1) xs
+
-- | The 'genericSplitAt' function is an overloaded version of 'splitAt', which
-- accepts any 'Integral' value as the position at which to split.
genericSplitAt :: (Integral i) => i -> [b] -> ([b],[b])
-genericSplitAt 0 xs = ([],xs)
+genericSplitAt n xs | n <= 0 = ([],xs)
genericSplitAt _ [] = ([],[])
-genericSplitAt n (x:xs) | n > 0 = (x:xs',xs'') where
- (xs',xs'') = genericSplitAt (n-1) xs
-genericSplitAt _ _ = error "List.genericSplitAt: negative argument"
+genericSplitAt n (x:xs) = (x:xs',xs'') where
+ (xs',xs'') = genericSplitAt (n-1) xs
-- | The 'genericIndex' function is an overloaded version of '!!', which
-- accepts any 'Integral' value as the index.