Is there a way to call Validated.zip on an Iterabl...

# arrow

[Jeff]

Is there a way to call Validated.zip on an Iterable instead of one of the overloaded forms? Is this a JVM optimization (I’ve seen Clojure do similar overloading instead of vararg).
eg.

val someIterable : List<Validated<MyError, String>> // from a map or something similar
someIterable.zip(Semigroup.nonEmptyList<MyError>()} {array -> ... }
//or
Validated.zip(someIterable, se) {array -> ... }

I’m borrowing Rx’s api for zips / FuncN for f.
Is this a JVM optimization? (I’ve seen Clojure do similar overloading instead of a single vararg form)

[simon.vergauwen]

Hey @Jeff,

If you’re looking for zip on Iterable I think you’re looking for traverseXXX.

In case of validated traverseValidated. There is also parTraverseValidated inside Arrow Fx Coroutines in case you want to run validation code in parallel.

[simon.vergauwen]

The signature however looks like this:

val someIterable: List<String> = ...

fun validate(str: String): ValidatedNel<MyError, String>

someIterable.traverseValidated { str ->
  validate(str)
} // ValidatedNel<MyError, String>

[simon.vergauwen]

The reason we don’t use vararg here is because there is a different type in every param.
So you can combine A, B, C into D.

Where with vararg all params have to be of the same type, so you’re restricted to A, A, A into D.

[simon.vergauwen]

So this is also the difference between zip and traverse. With zip you can combine values that of different types, while traverse works on a container (Iterable) which holds values of the same type.

[Jeff]

makes sense. thanks!