My understanding is `parTraverse` operation is dif...

# arrow

[Gopal S Akshintala]

My understanding is parTraverse operation is different from traverse operation. It's not just traverse operation in parallel. If I am not missing something, aren't their names kind of misleading?

[simon.vergauwen]

parTraverse works in a similar way as traverse. Although the signature is a little different in Concurrent as it is in Traverse.

We could've implemented parTraverse as an extension function of Traverse which would then require Concurrent instead of Applicative.

Additionally, as it's with all parallel operations. if you'd launch parTraverse on a single threaded pool, it'll behave the same as traverse on that single pool.

That's why in Arrow Fx Coroutines you see the following optimisation.
https://github.com/arrow-kt/arrow-fx/blob/master/arrow-fx-coroutines/src/main/kotlin/arrow/fx/coroutines/ParTraverse.kt#L93

Where having no dispatcher, or having an EmptyCoroutineContext parTraverse == traverse.

[Gopal S Akshintala]

Thank you @simon.vergauwen 🙂