[RFCs] Alef Component Concept

[ije]

A new component system will ship as part of v0.4, I want to try some new ideas to write components with JSX which should be simple, fast and typed. Those ideas are inspired by React and Svelte, it's standard JSX syntax, and with high performance AOT compiler in Rust. Core features include:

• Born in Typescript
• With Standard JSX Syntax
• AOT Compiler in Rust
• No Virtual DOM
• Reactive
• Builtin Styling
• SSR

import Logo from './Logo.alef'

const name: Prop<string> = 'World' // prop

let n: number = 0 // state
const double: Memo<number> = 2 * n // memo

// effect
$: () => {
  console.log('mounted')
  return () => console.log('unmounted')
}

function increase() {
  n++ // eq `setN(n => n+1)`
}

// elements
$t:
<div>
  <Logo />
  <h1>Hello {name}!</h1>
  <p onClick={increase}>double is {double}</p>
</div>

// styling
$style: `
  /* unused h1 (tree-shaking) */
  h1 {
    font-size: 200%;
  }
  p {
    color: ${Math.abs(n) >= 10 ? 'red' : 'green'}    
  }
`

Please star https://github.com/alephjs/alef-component to get project progress.

[shadowtime2000]

I like how it uses more implicit sections like Marko instead of explicitly being separated into different parts. @ije Do you have an idea of what the compiler output may look like for it? With no runtime, would it just compile into some variable declarations and some document manipulations?

[shadowtime2000]

@ije I'd recommend you create the compiler and such in a different repo called alef or something to allow others to more easily use it without Aleph.

[shadowtime2000]

I like it's conciness though compare it with React

import { useState } from "react";

function Counter() {
  const [count, setCount] = useState(0);

  return (
    <>
      <p>Count: {count}</p>
      <button onClick={() => setCount(count + 1)}>Increment!</button>
    </>
  );
}

let count = 0;

<>
	<p>Count: {count}</p>
	<button onClick={() => count++}>Increment!</button>
</>

[ije]

@shadowtime2000 yes, i will create a repo to implement this.

[ije]

@shadowtime2000 or no fragment

let count = 0;

<p>Count: {count}</p>;
<button onClick={() => count++}>Increment!</button>

[shadowtime2000]

@shadowtime2000 or no fragment

let count = 0;

<p>Count: {count}</p>;
<button onClick={() => count++}>Increment!</button>

Wow, even better!

[shadowtime2000]

@ije I am not an expert on web performance and bundle size, but wouldn't having no runtime cause a big bundle size with stuff like reactivity, actually rendering stuff, and memoization?

[ije]

huge application may have this issue, most applications should be lighter than react, we will see

[iFwu]

I think https://github.com/BuilderIO/jsx-lite and https://github.com/ryansolid/solid can be considered.

[shadowtime2000]

@iFwu What exactly do you mean by that? The compiler I believe will already use something like what SolidJS does, except I think in some cases it won't even do that.

[ije]

hey @iFwu, as @shadowtime2000 mentioned, the AOT compiler will transpile JSX to native Dom operations, no need to compile template in browser like solid do

[iFwu]

Thanks for replying. I got the difference now. At first look, I thought the concept is fairly alike to SolidJS. But I didn't see how the reactivity will be like in an AOT compiler. I will check Svelte for the details. If fine-grained reactivity with JSX can be implemented without templates, I'll be very excited.

[shadowtime2000]

@ije After v0.3.0 will we start slowly dropping React support or something? Or will React still be supported?

[ije]

@shadowtime2000 React is ever the first framework in Aleph.js, and i wish we can import react component in Alef Component in the future.

[shadowtime2000]

Will we add a feature like automatic selection of components depending on usage of Alef or React? Like if we import deno.land/x/aleph/link.ts, will it automatically import a deno.land/x/aleph/link/react.ts or a deno.land/x/aleph/link/alef.alef depending on what is importing it?

[shinspiegel]

I was wondering, we already have a lot of frameworks and ways to implement reactive (and non-reactive) web interfaces, do we need another one?

I think, should be better to implement other frameworks like Vue and Angular, which would fit best? Or I'm missing something?

[ije]

@shinspiegel i agree with you, the next stage(0.4) the most important idea i guess is to bring Vue to alephjs. Angular i'm not sure since i'm not the user of it.

[ije]

however, the alef component is an experience feature i want to try.

[shadowtime2000]

I think Angular may not be fit for this because it has a ton of tooling that needs to be set up for it to work. Vue would be pretty nice in setting it up.