async function load() {
    const [message] = await Scheme.load_main("hello.wasm", {}, {
        js: {
            alert: alert,
            prompt: prompt,
        },
        document: {
            body() { return document.body; },
            createTextNode: Document.prototype.createTextNode.bind(document),
            createElement: Document.prototype.createElement.bind(document),
        },
        element: {
            appendChild(parent, child) { return parent.appendChild(child); },
            setAttribute(elem, name, value) { elem.setAttribute(name, value); },
        }
    });
    console.log(message);
}
window.addEventListener("load", load);