A way of triggering a pipeline

[anantakrishna]

Suppose I'm building a pipeline which does not provide any expected result, i.e. it is an iterator of void.

What is the supposed/idiomatic way of triggering the pipeline in a functional way? I mean, not by for … of.

From the documentation, I see only drain() plus .first.

[vitaly-t]

If it is an iterator of void, it has no data, so what is triggering an unforeknown sequence is supposed to yield in your view?

P.S. Accessing .first always triggers the pipeline, but if it has no data, you will get no data.

[vitaly-t]

Are you trying to get something yielded when there is no data? For that, there is defaultEmpty operator.

[anantakrishna]

No, there is data initially. Then this data is processed asynchronously, values are transformed into Promise<void> and awaited using wait() operation. Thus, the pipeline yields a series of voids.

See the first example in https://vitaly-t.github.io/iter-ops/functions/wait.html. My case is almost same, just promises are of void. Therefore I don't want/need a for ... of loop to run the pipeline. I just want to run it.

Am I doing something stupid or misunderstanding anything?

[vitaly-t]

It's alright, just do await .first to trigger the pipeline, and it should be fine ;)

[anantakrishna]

All right. With drain(), right?

[vitaly-t]

Whatever works for you, I guess :) Also, check out custom mapWait ;)