Ohhh this is cool: github.com/dy/jz
JS syntax that compiles to pure WASM. No runtime, no GC.
![import jz from 'jz'
// 3 lines of JS → 120 bytes of WASM, compiles in <1ms
const { exports } = await WebAssembly.instantiate(jz(`
let { sin, PI } = Math
export let sine = (out, freq, t) => {
for (let i = 0; i < out.length; i++) out[i] = sin((t + i) * freq * PI * 2 / 44100)
}
`))
// Real-time audio at native speed, zero GC pauses
exports.sine(audioBuffer, 440, sampleOffset)](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:zmdqpvhi7mrerefow5jxqcb6/bafkreigzjzukdafrmpf5euvaxrzznnrltf2hzv76672oxognaubfmpvife)
WebAssembly from the Ground Up
@wasmgroundup.com
273 followers 191 following 75 posts
A book about WebAssembly by @marianoguerra.org and @dubroy.com — learn Wasm by building a simple compiler in JavaScript. wasmgroundup.com
![import * as w from "@wasmgroundup/emit";
const mod = w.module([
w.typesec([w.functype([w.valtype.i32, w.valtype.i32], [w.valtype.i32])]),
w.funcsec([w.typeidx(0)]),
w.exportsec([w.export_("add", w.exportdesc.func(w.funcidx(0)))]),
w.codesec([
w.code(
w.func(
[],
w.expr([
[w.instr.local.get, ...w.i32(0)],
[w.instr.local.get, ...w.i32(1)],
w.instr.i32.add,
]),
),
),
]),
]);
const { instance } = await WebAssembly.instantiate(w.flatten(mod));
const { add } = instance.exports as { add: (a: number, b: number) => number };
console.log(add(1, 2)); // 3](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:zmdqpvhi7mrerefow5jxqcb6/bafkreib7rlnvsbx32nrijvdoxfkn54ipbwrqalampo3i5qjlaynim5aepi)
![// im*:vec(import)
export function importsec(ims) {
return section(SECTION_ID_IMPORT, vec(ims));
}
// mod:name nm:name d:importdesc
export function import_(mod, nm, d) {
return [name(mod), name(nm), d];
}
export const importdesc = {
// x:typeidx
func(x) {
return [0x00, typeidx(x)];
},
};](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:zmdqpvhi7mrerefow5jxqcb6/bafkreig3vx6db3x3iuay3mlquwpobn7hgig2nsyvqny25g6lxzyyy4pbky)
