[Haskell-beginners] short function to remove and replace an item

What if I have a list xs, and I want to remove one item and replace it with another? The item to remove can be detected by a predicate function. The order of the items doesn't matter. How about this: replaceItem :: (a -> Bool) -> a -> [a] -> [a] replaceItem p new xs = new : snd (partition p xs) This will actually replace all items that match the predicate with one copy of 'new'. It will also prepend 'new' even if no items match the predicate. For another challenge, can someone explain to me how to write this in point-free style? Thanks, Mike