wasm-script
This is a library for bringing your WebAssembly compiler to the web.
Vision
<script src="wasm-script.js"></script>
<wasm-script id="math" lang="c" compiler="http://yourcompiler.com/c.wasm">
extern int add(int a, int b){
return a + b;
}
</wasm-script>
<script type="module">
// Compile as a module for accelerating javascript
const mathModule = await document.getElementById("math").compile();
console.log(mathModule.add(2,2));
</script>Or run stand alone
<script src="wasm-script.min.js"></script>
<wasm-script lang="python" src="tetris.python" execute></wasm-script>
<!-- use default compilers from the community for certain languages -->Features
- script for loading a WebAssembly module from a compiler
- ask to load dependent files by url
- cacheing
- show compile errors in console
CDN
https://cdn.jsdelivr.net/gh/richardanaya/wasm-script@latest/wasm-script.js
Reference Implementation
A reference implementation compiler is in progress in Rust for the wasp programming language ( a simple lisp-like syntax language ).
<script src="wasm-script.js"></script>
<wasm-script id="math" lang="wasp" compiler="compilers/waspc/compiler.wasm">
pub fn secret(){
42
}
</wasm-script>
<script>
// top-level await doesn't exist yet, so we have to do it the lame way
(async function(){
const mathModule = await document.getElementById("math").compile();
document.body.innerHTML = mathModule.secret(1);
})();
</script>See the demo here
What the compiler is doing is fairly simple:
use wasm_compiler::{process,log};
use wasp_core::{compiler, parser};
#[no_mangle]
pub fn compile(code_ptr: usize) -> usize {
process(code_ptr, |code| {
log("compiling the code below!!");
log(&code);
let app = parser::parse(code)?;
Ok(compiler::compile(app)?)
})
}Exposing Browser Functionality
Until we have DOM exposure in WebAssembly, we still are in a position we need to provide our own exposures to the browser's functionality. This library has some helper functions for common memory structures.
<script src="../wasm-script.js"></script>
<wasm-script id="math" lang="wasp" compiler="../compilers/waspc/compiler.wasm">
extern console_log(message)
pub fn main(){
console_log("hello world!")
}
</wasm-script>
<script>
// top-level await doesn't exist yet, so we have to do it the lame way
(async function(){
const mathModule = await document.getElementById("math").compile({
console_log: function(message_start) {
const message = WasmScript.getCString(mathModule.memory,message_start)
document.body.innerHTML += message;
}
});
mathModule.main();
})();
</script>See the demo here
Memory Helper API
WasmScript.getCString(mem,start)- Returns a utf-8 string from position in memory that ends with a zero character.WasmScript.getUint8ArrayFromMemory(mem,start)- Returns a Uint8Array from position in memory, starting with a uint32 count followed by the elements.
Building Your Own Compiler
Right now the current contract for building a compiler is very simple and can be implemented in any language that compiles to WebAssembly:
// external function to print a long takes a zero-character ending C string
extern void compiler_log(uint32 start_cstr)
// external function to print a error log and throw an exception takes a zero-character ending
// C string ( this function does not return )
extern void compiler_error(uint32 start_cstr)
// allocate some bytes of size
uint32 malloc(uint32 size)
// compile a code by passing in the start of the code in memory (created using malloc above).
// and get back a list of bytes (the length as u32, followed by the data)
uint32 compile(uint32 code_str)