Stateful variables (streams, live variables, reactivity, ... whatever we call it)

[dumblob]

What could be the most convenient way to model something like https://github.com/MaiaVictor/PureState in Kind?

I'm starting to tinker with Kind a bit, but I'm still too far away from writing anything bigger than hello world 😉.

[VictorTaelin]

Imagine a runtime like Haskell's STG, except that it allowed mutable variables. Of course, if you mutate a variable, then you break purity and referential transparency... but not if you "notify" every thunk or expression that depended on the mutable variable, and then re-compute their values. It would be as if a physics constant changed and the whole universe was re-computed to consider it. Something like that would allow, say, react-like UI management without needing to compute diffs. I think it is a fun concept and I could see a runtime based on it. It can also probably be easily modeled in Kind, using monads to have a nice syntax for it. But other than that I don't think there is much else to say about it. I don't see any interesting / compelling use other than UIs.

[dumblob]

It can also probably be easily modeled in Kind, using monads to have a nice syntax for it.

Do you have anything specific in mind?

But other than that I don't think there is much else to say about it. I don't see any interesting / compelling use other than UIs.

Yep, it's for UI of all kind. But UIs are important - even printf() is UI, so I feel this concept be quite useful in most apps 😉. Such "live" UIs (including distant collaboration!) are yet to become ubiquitous IMHO.

[VictorTaelin]

Do you have anything specific in mind?

Not in mind, just a guess.

Yep, it's for UI of all kind. But UIs are important - even printf() is UI, so I feel this concept be quite useful in most apps 😉. Such "live" UIs (including distant collaboration!) are yet to become ubiquitous IMHO.

Fair enough, but when it comes to UIs, we're currently betting on React-like interfaces. Check the apps on http://uwu.tech/ currently. So observables isn't something I plan to invest on anytime soon.

[dumblob]

Fair enough, but when it comes to UIs, we're currently betting on React-like interfaces.

Sounds rather heavy-weight and not so quick to develop & maintain. Have you also considered a bit lighter-weight paradigms? E.g. something like:

1. https://github.com/adamhaile/S (like PureState but minimizing the "problem with conditions")
2. https://github.com/WebReflection/domdiff (I usually prefer this one among other options here)
3. https://github.com/ajnsit/concur-js (inspiration in Haskel concur)
4. https://github.com/ms-jpq/noact (tiny React)
5. https://github.com/sweetpalma/gooact (tiny React)
6. https://github.com/zserge/o (tiny React)
7. https://github.com/paldepind/flyd (explicit streams - quite verbose, but it gets the job done)

It can also be seen as a form of pub sub pattern - so even https://github.com/moothyknight/JS_UI_Utils would do the job in the end.

Check the apps on http://uwu.tech/ currently.

Looks good to me (assuming the size of the generated JS files will get smaller at some point).

[dumblob]

As a side note, there is also a whole language which has all variables "live" - see https://github.com/mech-lang (it's based on what the Eve language achieved - the video shows what such "live" functional-declarativeness offers - and it's not negligible!).