What Are Signals?

Post by dmitriid » Sun, Mar 05, 2023, 9:14 AM UTC

satvikpendem wrote: post #9

I don't really understand why people like signals again. I used a signals-like reactive programming model in VueJS a while ago and hated that you could never be sure exactly where things were being changed. Thankfully it seems that the React creators and maintainers are not hopping on the signals train and are instead adamant about unidirectional dataflow with explicit mapping of state to UI, which, as has been the r…

Post by marcosdumay » Sun, Mar 05, 2023, 4:15 PM UTC

uxcolumbo wrote: post #18

marcosdumay wrote: post #11

Earlier quoted context omitted.

My impression is that Javascript is just an horrible language to create reactive systems, and that default purity with explicit effects is extremely underrated. (But then, I was already biased.) It is hard to even make sense of the discussion without imagining the details of how those frameworks are implemented. And the discussion on the level of normal usage, not something advanced or development oriented.

What language(s) would you recommend for building reactive systems?

Post by satvikpendem » Sun, Mar 05, 2023, 9:32 PM UTC

dmitriid wrote: post #53

satvikpendem wrote: post #35

Earlier quoted context omitted.

Personally I just use Redux Toolkit with RTK Query for any synchronization with backend state. What I like about Redux is that it takes the immutable functional approach, you cannot change previous state but must instead derive new state from the old state very explicitly. In this way, it's the antithesis of signal-based state.

> What I like about Redux is that it takes the immutable functional approach Strange that you don't like spaghetti, but then praise Redux that is spaghetti exemplified: dozens of functions, and wrappers, and hooks eerywhere. Trying to trace how a value gets changed through the three-four layers of wrappers is like pulling teeth through the anus. And looking at the current reincarnation of this abomination, it is marg…

Post by dmitriid » Mon, Mar 06, 2023, 9:14 AM UTC

satvikpendem wrote: post #56

dmitriid wrote: post #53

Earlier quoted context omitted.

> What I like about Redux is that it takes the immutable functional approach Strange that you don't like spaghetti, but then praise Redux that is spaghetti exemplified: dozens of functions, and wrappers, and hooks eerywhere. Trying to trace how a value gets changed through the three-four layers of wrappers is like pulling teeth through the anus. And looking at the current reincarnation of this abomination, it is marg…

Redux Toolkit is very impressive, especially with TypeScript. I'd agree that there was a lot of boilerplate in the before-times, but today, it's not "marginally less," it's significantly less boilerplate. The debugging tools are top notch as well, I can trace values and their changes pretty easily these days. The main point of Redux is that it follows functional programming paradigms of immutable data, which makes re…

   // redux

   import { useSelector, useDispatch } from 'react-redux'
   import { decrement, increment } from './counterSlice'

   export function Counter() {
     // note how we reach into magical global state that useSelector knows about
     const count = useSelector((state: RootState) => state.counter.value)
     const dispatch = useDispatch()

     return 
         dispatch(increment())}>Increment
        {count}
         dispatch(decrement())}>Decrement
     ;
   }


   // solid

   // state is immutable. It's also not magical, you explicitly refrence and import it
   //
   // increment and decrement would use a `set` function to update the store to required value
   // see https://www.solidjs.com/docs/latest/api#createstore
   // and https://www.solidjs.com/docs/latest/api#updating-stores
   //
   import { state, increment, decrement } from './counter-store';

   export function Counter() {
     return 
         increment()}>Increment
        {state.count}
         decrement()}>Decrement
     ;
   }

Post by satvikpendem » Mon, Mar 06, 2023, 5:50 PM UTC

dmitriid wrote: post #58

satvikpendem wrote: post #56

Earlier quoted context omitted.

Redux Toolkit is very impressive, especially with TypeScript. I'd agree that there was a lot of boilerplate in the before-times, but today, it's not "marginally less," it's significantly less boilerplate. The debugging tools are top notch as well, I can trace values and their changes pretty easily these days. The main point of Redux is that it follows functional programming paradigms of immutable data, which makes re…

> Compare that to the global state everywhere of signals/reactive/observables-based approaches like MobX or RxJS. What are you on about? Redux is literally about global state everywhere. But with three to four layers of abstractions between. You define your state globally. Then use hooks to fetch data from that global state, and then "dispatch" aka call actions on that global state. If something else somewhere else u…