
7 Apr
2017
7 Apr
'17
4:42 a.m.
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