undefined | Better HN

0 pointsWorldMaker1y ago0 comments

> I don't _think_ it supports "concurrent" iteration

I believe what you are calling a "concurrent" iteration is one of the use cases for Observables, so would be on the RxJS side (the "parent" project).

> It doesn't have a "reducer" concept with composition and what not

Interesting. I'll read further on what you are doing there. Seems possibly similar to Lenses/Prisms in FP, with different rules.

> It doesn't have a concept of "optionals"

Good point. So far I've not found a JS approach to optionals I'm entirely happy with. I've had some suggest I should give Effect [0] a deeper look, but given I'm mostly happy with RxJS the bulk of Effect doesn't appeal to me. The dual of an Option being an iterator with 0 or 1 values is something I've seen before and something to keep in mind.

[0] https://effect.website/docs/data-types/option/

0 comments

2 comments · 1 top-level

tomeraberbach1y ago· 1 in thread

> I believe what you are calling a "concurrent" iteration is one of the use cases for Observables, so would be on the RxJS side (the "parent" project).

Ah, got it. I don't think I quite understood the relationship between this project and RxJS. I did know about RxJS's observables, yes. I do sort of hint at the relationship between concurrent iterables and the observables [1], but I tried to make concurrent iterables a bit more specialized to what you'd normally use an iterable for.

> Interesting. I'll read further on what you are doing there. Seems possibly similar to Lenses/Prisms in FP, with different rules.

I think I've heard of lenses (but not prisms), but don't think I ever actually learned what they are. Would be curious if you find a connection between those and my reducers :)

> Good point. So far I've not found a JS approach to optionals I'm entirely happy with. I've had some suggest I should give Effect [0] a deeper look, but given I'm mostly happy with RxJS the bulk of Effect doesn't appeal to me. The dual of an Option being an iterator with 0 or 1 values is something I've seen before and something to keep in mind.

Yeah, I liked representing optionals as iterables because you get a lot of functionality for "free" [2]

[1] https://lfi.dev/docs/concepts/concurrent-iterable#:~:text=A%....

[2] https://lfi.dev/docs/concepts/optional#why-use-iterables-to-...

WorldMakerOP1y ago

Prisms are Lenses through Options. They compose very similarly to Lenses and it is easy to convert a Lens to a Prism to compose Prisms from existing Lenses. Every Lens is a very simple "degenerate" Reducer (a Lens is just a getter and a setter from one "state" to another), but Prisms feel even more like "real" Reducers because of the optional states that can be involved. So Prisms and Lenses are very common composable Reducers in some styles of FP.

j / k navigate · click thread line to collapse