There's also newtype First wraping a Maybe in Data.Monoid, in which you can wrap your Maybes, mconcat them and get the first Just value. Like:
mconcat $ map First [Nothing, Just "first", Nohing, Just "last", Nothing] First {getFirst = Just "first"}
On Thu, Nov 3, 2011 at 6:07 PM, Hugo Ferreira
Hello,
Apologies the simpleton question but I would like to know how it is done in Haskell. I have a list of values, and I am applying a function to each of these elements. The result is a Maybe. I would like to return the first occurrence which is not a Nothing.
I am considering something like:
selectOne f = take 1 . filter (\e -> case e of Just _ -> True _ -> False ) . map f
I this how it is done?
TIA, Hugo F.
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