[feat] Support of Signals

[motss]

Is your feature request related to a problem? Please describe.
I knew that there is already an existing useProp() and useState() which already do their job just nice. I wonder if Signals is a valid feature to be considered in atomico.

Describe the solution you'd like

import { html, useSignal } from 'atomico';

function MyComponent() {
  const $count = useSignal(0);
  
  return html`
  <host shadowDom>
    <button onclick=${() => $count.value--}>-</button>
    <span>${count.value}</span>
    <button onclick=${() => $count.value++}>+</button>
  </host>
  `;
}

Describe alternatives you've considered
useState() does the same thing already.

Additional context

Prior arts:

1. Solid's Signals
2. Preact's Signals
3. Qwik's Signals

[UpperCod]

Hi @motss , it depends on the benefits. Currently, a syntax similar to signals can be achieved based on useHost.

import { html, useHost } from 'atomico';

function myComponent() {
  const { current } = useHost<typeof MyComponent>();
  
  return html`
    <host shadowDom>
      <button onclick=${() => current.value--}>-</button>
      <span>${current.value}</span>
      <button onclick=${() => current.value++}>+</button>
    </host>
  `;
}

myComponent.props = { count: { type: Number, value: 0 } };

export const MyComponent = c(myComponent);

customElements.define("my-component", MyComponent);

By the way, I generated a post on Discord at some point to propose an alternative to signals: Discord Post. I invite you to participate on Discord.

[TheJaredWilcurt]

Alien-Signals is a low level signal library that is the current fastest implementation. Vue 3.6 will be switching over to using it under the hood to power their reactivity API's. Nothing changes for Vue users. Alien-Signals will continue to be maintained as a separate library, with the intent of having more frameworks use it to power their reactivity system.

The TC39 Signals Polyfill is the current working implementation for TC39 proposal to officially add a signals API into the browser. Alien-Signals also works as a polyfill for that implementation with no performance loss. Since Atomico is built on native webcomponents, having something compatible with the TC39 signals EcmaScript proposal would be logical (though it's probably years off from being finalized).

Also Alien-Signals performance has almost doubled since the above chart was created.

https://github.com/stackblitz/alien-signals