Acorn VS Svelte

Why do we then have other JavaScript parsers like babel parser, swc parser, acorn, espree and the likes since JavaScript engines have their own internal parsers?

If you're trying to determine if a string is valid Javascript then your best bet is to use a JS parser like Acorn. Trying to DIY parsing with just regex is a good way to end up incredibly frustrated.

To render UI I use Svelte. To parse JS files I use Acorn JS in Web Worker.

Behind Babel is created by an Australian developer Sebastian McKenzie and now consists a small team of contributors. Babel also makes uses a polyfill library called core-js, which in turn uses a JavaScript parser, acorn.

At line 3, we import parseScript from meriyah which is a JavaScript parser (could have been babel, acorn, swc, etc doesn't matter for our use case as long as they correctly implement the spec).

A simple starting point is Acorn with estree-walker. Not sure if you'll need more advanced functionality but that pair has worked well for my usage. It's also the combo that Svelte uses internally.

https://github.com/acornjs/acorn For parsing the tree

the technical decision how Svelte should treat self-closing html elements was hindered by Prettier:

Svelte

React has introduced measures like batching state updates, background concurrent rendering and memoization to tackle this. My opinion is that the best way to solve the problem is by improving their reactivity model. The app needs to be able to track the code that should be re-run on updating a given state variable and specifically update the UI corresponding to this update. Tools like solid.js and svelte work in this manner. It also eliminates the need for a virtual DOM and diffing.

Similarly to Promises/A+, this effort focuses on aligning the JavaScript ecosystem. If this alignment is successful, then a standard could emerge, based on that experience. Several framework authors are collaborating here on a common model which could back their reactivity core. The current draft is based on design input from the authors/maintainers of Angular, Bubble, Ember, FAST, MobX, Preact, Qwik, RxJS, Solid, Starbeam, Svelte, Vue, Wiz, and more…

Svelte is a powerful web framework that offers a fresh approach to building web applications. Its simplicity, reactivity model, and built-in features make it an excellent choice for developers looking to create efficient and maintainable applications. By following this guide, you should now have a good understanding of how to get started with Svelte and build your first components, routes, and transitions. You can read more about svelte on the official Svelte website.

Use .NET features (especially dotnet watch) as a setup for a client-side Svelte application, starting from a simple C# console app.