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Managing State with Signals

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Re: Managing State with Signals

#31

Post by ed_blackburn »

bheadmaster wrote: post #29
klabb3 wrote: post #14

Earlier quoted context omitted.

I feel like reactive programming is approaching ripeness for a mainstream programming language or cross-stack paradigm within the next few years. React, Svelte, Redux etc in the frontend world has certainly paved the way on the mainstream side, albeit in a simplified environment (singlethreaded, does not cross the network boundary and can simply share memory cheaply). I wonder if a refined version of this with will p…

What's the difference between reactive and functional programming? Both seem to focus on expressing relationships between objects and having compiler/runtime infer the computation, instead of explicitly specifying the computation.

Perhaps if you framed your question subtly differently and asked yourself what is the difference between Erlang and OTP, the answer maybe easier to discern?

Re: Managing State with Signals

#33

Post by bheadmaster »

ed_blackburn wrote: post #31
bheadmaster wrote: post #29

Earlier quoted context omitted.

What's the difference between reactive and functional programming? Both seem to focus on expressing relationships between objects and having compiler/runtime infer the computation, instead of explicitly specifying the computation.

Perhaps if you framed your question subtly differently and asked yourself what is the difference between Erlang and OTP, the answer maybe easier to discern?

What's the exact difference between Erlang and OTP that would answer my question?

Re: Managing State with Signals

#34

Post by Bogdanp »

I took a similar approach in my Racket library, gui-easy[1,2]. Though I opted to not defer any computations. Any observable (similar to a signal from the post) update propagates to observers immediately, and there's no incrementality -- observables are just boxes whose changes you can subscribe to. Regarding the disposal problem, I used weak references and regarding the where to take observables and where to take concrete values as input question, I decided that any place an observable can go in, a concrete value can as well and it's been a convenient choice so far. For fun, here's an example[3] that builds the todo UI from the post.

[1]: https://docs.racket-lang.org/gui-easy/index.html

[2]: https://www.youtube.com/watch?v=7uGJJmjcxzY

[3]: https://github.com/Bogdanp/racket-gui-easy/blob/364e8becaafa...

Re: Managing State with Signals

#36

Post by can16358p »

jackdh wrote: post #9
red_trumpet wrote: post #6

Earlier quoted context omitted.

Wow, truly night mode. Hilarious!

Should really call it spotlight mode! On a side note, if you do want a normal darkmode, the Darkreader extension works very well including on this site.

Too much skeuomorphism at its finest: real "dark" mode that it simulates pointing a flashlight.

Re: Managing State with Signals

#37

Post by awestroke »

mpweiher wrote: post #11

It looks like we are going to keep reinventing dataflow constraints[1] over and over again, always with slightly different terminology (Rx, FRP, signals, ...) So it (a) appears to be a very useful or at least attractive concept, and (b) somehow difficult to fit into current programming languages/practice in a clean way. [1] https://blog.metaobject.com/2014/03/the-siren-call-of-kvo-an... (HN: https://news.ycombinator.…

The idea in and of itself is not what is being rediscovered. Nobody is reinventing the wheel. It's whether the implementation is ergonomic and powerful that determines whether it catches on.

Re: Managing State with Signals

#38

Post by ReleaseCandidat »

bheadmaster wrote: post #29
klabb3 wrote: post #14

Earlier quoted context omitted.

I feel like reactive programming is approaching ripeness for a mainstream programming language or cross-stack paradigm within the next few years. React, Svelte, Redux etc in the frontend world has certainly paved the way on the mainstream side, albeit in a simplified environment (singlethreaded, does not cross the network boundary and can simply share memory cheaply). I wonder if a refined version of this with will p…

What's the difference between reactive and functional programming? Both seem to focus on expressing relationships between objects and having compiler/runtime infer the computation, instead of explicitly specifying the computation.

Most of the time the term used is "Functional Reactive Programming". If that answers your question.

Although there exists a paper about "Reactive Imperative Programming" (with Dataflow Constraints): https://typeset.io/pdf/reactive-imperative-programming-with-...

Re: Managing State with Signals

#40

Post by ed_blackburn »

bheadmaster wrote: post #33
ed_blackburn wrote: post #31

Earlier quoted context omitted.

Perhaps if you framed your question subtly differently and asked yourself what is the difference between Erlang and OTP, the answer maybe easier to discern?

What's the exact difference between Erlang and OTP that would answer my question?

OTP is the means by which the programming language is able to accomplish tasks such as process to process comms, how to supervise actors etc. It's the enabler for the distributed computing compared to Erlang which is the programming language. They're (obviously) complementary but OTP is the magic that enable one to deliver on the reactive manifesto. Functional programming needs augmenting with mechanisms that provide the distributed computing features, it's not enough on its own.
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