Splitting the Compiler from the Runtime in Levelo JS

Splitting the Compiler from the Runtime in Levelo JS

Yesterday was focused on improving the architecture of Levelo JS rather than adding flashy features.

One of the biggest changes was separating the Vite compiler from the core framework.

Previously, the compiler lived inside the main levelojs package. Now it has been extracted into its own package:

Installation:

npm install levelojs vite-plugin-levelojs

or

pnpm add levelojs vite-plugin-levelojs

This makes the runtime cleaner, easier to maintain, and allows the compiler to evolve independently.

What's New

Batch Updates

Levelo JS now includes a new batch() API.

batch(() => {

  setCount(v => v + 1);

  setUser("MotionMind");

  setCount(v => v + 1);

});

Multiple state updates are grouped together, reducing unnecessary reactive executions and improving performance.

Reactive Input Tracking

Reactive value binding for form elements has been improved.

Previously, updating a signal didn't automatically synchronize the value of inputs in every case.

Now developers can simply write:

const [message, setMessage] = state("");



<input

  value={message()}

  onInput={(e) => setMessage(e.target.value)}

/>

The input stays synchronized with the reactive state automatically.

Dedicated Vite Plugin

The compiler is now available as an official package:

• vite-plugin-levelojs

It compiles JSX into optimized h() calls at build time, eliminating the need for a Virtual DOM.

Runtime Refactoring

The internal JSX runtime has also been reorganized.

The h() factory has been extracted into its own runtime module for better code organization and maintainability.

Verified in a Real Project

After publishing the new packages, everything was tested inside a real Vite application.

The compiler, runtime, JSX transformation, and reactivity all worked as expected.

This update isn't about adding new UI features.

It's about making the foundation stronger before building bigger things on top of it.

More improvements are coming soon.

GitHub: