Hello Haskell Cafe,

I had to write the following function and I was wondering if it (or its generalization to Alternative or Traversable) was exposed by some library under a different name:

first [] = Nothing

first (t:ts) = fmap (:ts) (s t) <|> fmap (t:) (first ts)

Somehow it is to "traverse" as "any" is to "all".

Cheers,

Paul