if I have a `List<A>` and a function `A -&gt...

# arrow

[Frank]

if I have a List<A> and a function A -> Option<B>, is there an operator, or series of operators, that would iterate over the list, applying the function, and return the first Option<B> that is a Some<B>, and if none do, returns None? Similar to a findFirst but runs a computation

[Jannis]

There are multiple ways to do this:
First the most basic one is: filterMap(f).firstOption() using filterMap from FunctorFilter and firstOption from Foldable . (If you do the same with asSequence().filterMap(f).firstOption() it'll also be lazy ^^).
When this pr (https://github.com/arrow-kt/arrow/pull/1897) is merged you can also do map(f).asum(Option.alternative(), ListK.foldable()) asum basically tries every element and short-circuits on success (which is similar to traverse which short-circuits on failure).
I'd suggest doing the asSequence().filterMap(f).firstOption() because it won't apply the function unnecessarily and because it is available now ^^.

[Frank]

Oh that’s great! thanks for the reply! I’ll try it out!