nativejs-compiler

2.0.0 verified Fri May 01 auth: no javascript

nativejs-compiler (also known as hardware.js) is a JavaScript/TypeScript to C transpiler that converts JS/TS code into readable C89 code for low-power microcontrollers and IoT devices. Current version 2.0.0 (released July 2024) supports approximately 50% of ES3 syntax, targeting environments with very limited memory (512 bytes to 120KB RAM). Key differentiators include generating minimal, readable C code without unnecessary overhead, and employing escape analysis for memory management. It supports basic ES3 features like var, if-else, loops, functions, arrays, strings, and some built-in objects, but notably lacks support for float numbers, `this`, `new`, and `typeof`. Releases are occasional, focused on incremental feature coverage. Compared to other JS-to-C transpilers, it prioritizes output readability and small footprint over full language support.

Common errors

error Error: Cannot find module 'nativejs-compiler' ↓

cause Package is not installed or wrong package name used.

fix

Run npm install nativejs-compiler and ensure the package name is 'nativejs-compiler'.

error TypeError: nativejs_compiler_1.transpile is not a function ↓

cause Using CommonJS require instead of ESM import.

fix

Use import { transpile } from 'nativejs-compiler' instead of const { transpile } = require('nativejs-compiler').

error Unsupported feature: This expression (this) ↓

cause The `this` keyword is not supported by the transpiler.

fix

Remove usage of this or refactor code to use explicit parameters.

Warnings

breaking ESM-only since v2.0.0: The package no longer supports CommonJS require() syntax. ↓

fix Use import syntax instead of require().

deprecated The `transpile` function is deprecated in favor of `compile`; `transpile` may be removed in v3.0.0. ↓

fix Replace transpile() with compile().

gotcha Float numbers are not supported; using them will cause compile-time errors or incorrect output. ↓

fix Use integer values only, or check if float support is added in future versions.

gotcha The `this` keyword is not supported; transpiling code that relies on `this` will fail. ↓

fix Avoid using `this` or rewrite code to pass context explicitly.

gotcha Only about 50% of ES3 features are implemented; using unsupported syntax will cause transpilation errors. ↓

fix Refer to COVERAGE.md in the GitHub repo for the current list of supported features.

Install

npm install nativejs-compiler

yarn add nativejs-compiler

pnpm add nativejs-compiler

Imports

transpile

wrong

const transpile = require('nativejs-compiler').transpile

correct

import { transpile } from 'nativejs-compiler'

ESM-only since v2.0.0; CommonJS require will throw.

compile
wrong
```
import compile from 'nativejs-compiler'
```
correct
```
import { compile } from 'nativejs-compiler'
```
`compile` is a named export, not default. The default export is not available.
CompilerConfig
wrong
```
import { CompilerConfig } from 'nativejs-compiler'
```
correct
```
import type { CompilerConfig } from 'nativejs-compiler'
```
CompilerConfig is a TypeScript type, not a runtime value. Use `import type` to avoid runtime errors.

Quickstart

Transpiles a simple JavaScript 'Hello world' console.log to C code using the transpile function.

import { transpile } from 'nativejs-compiler';
const jsCode = `console.log("Hello world!");`;
const cCode = transpile(jsCode);
console.log(cCode);
// Output:
// #include <stdio.h>
// int main() {
//     printf("Hello world!\n");
//     return 0;
// }