Re: [Haskell-beginners] Searching Maybe lists

On Mon, May 18, 2009 at 9:56 PM, aditya siram wrote:

Hi all, I would like to define a function that takes a list and a function that evaluates each member of the list to a Maybe value and output the first element in the list that evaluates to 'Just y', or 'Nothing' once the list has been completely processed. So something like:

findMaybe :: [a] -> (a -> Maybe b) -> Maybe b

There are a couple of ways, the first one I could think of was:

findMaybe xs f = mconcat $ map f xs

where mconcat is found in Data.Monoid Antoine