Lucent

Experimental: not for production. APIs and the language subset change without a migration path.

Write React Native native modules in TypeScript. Lucent compiles a checked subset to C++ and calls it through JSI: no Swift or Kotlin to write, and no JavaScript engine in native code.

// src/geo.lucent.ts
export type Point = { x: number; y: number };

export function squaredDistance(a: Point, b: Point): number {
  const dx = a.x - b.x;
  const dy = a.y - b.y;
  return dx * dx + dy * dy;
}

import { squaredDistance } from "./src/geo.lucent";
squaredDistance({ x: 0, y: 0 }, { x: 3, y: 4 }); // 25, computed in C++

A module also calls the iOS and Android SDKs directly, typed from your Xcode and Android SDK. One module holds both platforms:

// src/clipboard.lucent.ts
import { PLATFORM } from "lucent:platform";
import { UIPasteboard } from "lucent:ios/UIKit";
import { ClipboardManager, ClipDescription } from "lucent:android/android.content";
import { appContext } from "lucent:android";
import { main } from "lucent:thread";

export async function hasStringAsync(): Promise<boolean> {
  if (PLATFORM === "ios") {
    return UIPasteboard.general.hasStrings;
  } else {
    return main(
      () =>
        appContext()
          .getSystemService(ClipboardManager)
          ?.getPrimaryClipDescription()
          ?.hasMimeType(ClipDescription.MIMETYPE_TEXT_PLAIN) ?? false,
    );
  }
}

Works in bare React Native (0.88+) and Expo (SDK 58+, development builds).

Install

npm i -D @lucent-lang/lucent
npx lucent init

Docs

What is Lucent · Install · Tutorial · How it works · Guides · Reference · Examples · Roadmap

Develop

pnpm install
pnpm test                      # compiler and CLI tests
pnpm test:runtime              # C++ runtime tests
pnpm test:e2e                  # compiled modules against the same code as JavaScript (needs Hermes)
node scripts/website.ts   # the website's generated files, samples, links and prose

CONTRIBUTING.md covers the setup, every suite and the commit style; docs/ holds the architecture and the specs.

MIT Lucent