js-bindgen

Generate WebAssembly bindings to JavaSCript via js-wasm for various languages:

• Rust
• C

cargo install js-bindgen

Getting Started

This project is able to take JavaScript API descriptions in yaml like the one below:

yaml - namespace: console functions: clear: log: parameters: - name: msg type: string warn: name: warning parameters: - name: msg type: string error: parameters: - name: msg type: string time: parameters: - name: msg type: string timeEnd: parameters: - name: msg type: string

And turn them into code.

Rust

js-bindgen --lang rust console.yaml

```rust

![no_std]

use js::*;

mod console { pub fn clear() { js!("function(){ console.clear(); }") .invoke_0(); }

pub fn log(msg: &str) {
    js!("function(strPtr,strLen){
        console.log(this.readUtf8FromMemory(strPtr,strLen)); 
    }")
    .invoke_2(msg.as_ptr() as u32, msg.len() as u32);
}

pub fn warning(msg: &str) {
    js!("function(strPtr,strLen){
        console.warn(this.readUtf8FromMemory(strPtr,strLen)); 
    }")
    .invoke_2(msg.as_ptr() as u32, msg.len() as u32);
}

}

... ```

C

js-bindgen --lang c console.yaml

```C

include "js-wasm.h"

void consoleclear() { static int fn; if(fn == 0){ fn = jsregister("function(){\ console.clear();\ }"); } js_invoke0(fn); }

void consolelog(char *msg) { static int fn; if(fn == 0){ fn = jsregister("function(strPtr,strLen){\ console.log(this.readUtf8FromMemory(strPtr,strLen));\ }"); } js_invoke2(fn, msg,strlen(msg)); }

void consolewarning(char *msg) { static int fn; if(fn == 0){ fn = jsregister("function(strPtr,strLen){\ console.warn(this.readUtf8FromMemory(strPtr,strLen));\ }"); } js_invoke2(fn, msg, strlen(msg)); }

... ```

Custom Code

Sometimes you may want to create a binding to code that doesn't exist and still have the power to generate libraries for many targets

- namespace: unicorn functions: makeUnicorns: code: | function() { console.log("🦄🦄🦄") }