Javascript Interop

[csjh]

Goals:

• Vite plugin, enabling import { func } from "./something.mite"
  • func should be able to return arbitrary numerical-based struct/num/etc
    • arbitrary numerical-based struct would be (wasm/mite-side) heap allocated
      • maybe a special part of the heap with sizeof(struct)-sized chunks for faster alloc?
    • automatically allocated (memcpy) w/ returned stack variables
    • property accessing is just getter/setter wrapping dataview.set<somenum> or nested struct
    • free'd with FinalizationRegistry
• Typescript type gen
• Handle v128 somehow
• Should generate something like

declare const wasm_memory: WebAssembly.Memory;
declare const _free: (ptr: number) => void;
const freedom = new FinalizationRegistry<number>((ptr) => _free(ptr));

class MyStruct {
    #view: DataView;
    static sizeof = 12;

    constructor(ptr: number) {
        this.#view = new DataView(wasm_memory.buffer, ptr, MyStruct.sizeof);
        freedom.register(this, ptr);
    }

    get x(): number {
        return this.#view.getUint32(0, true);
    }
    set x(value: number) {
        this.#view.setUint32(0, value, true);
    }

    get y(): bigint {
        return this.#view.getBigInt64(0, true);
    }
    set y(value: bigint) {
        this.#view.setBigInt64(0, value, true);
    }
}

for

struct MyStruct {
    u32 x;
    i64 y;
}

• special case primitive arrays into their corresponding TypedArray representation
• otherwise just use something like Array.from({ length: returned_length }, (_, i) => new MyStruct(base + i * MyStruct.sizeof))