async function load() {
  const procMap = new WeakMap();

  function wrapProc(obj) {
    function makeWrapper() {
      const proc = scheme.to_js(obj);
      function wrapper (...args) {
        return proc.call(...args);
      }
      procMap.set(obj, wrapper);
      return wrapper;
    }

    return procMap.get(obj) || makeWrapper();
  }

  const mod = await SchemeModule.fetch_and_instantiate("game.wasm", {}, {
    window: {
      get() {
        return window;
      },
      innerWidth() {
        return window.innerWidth;
      },
      innerHeight() {
        return window.innerHeight;
      },
      requestAnimationFrame(proc) {
        window.requestAnimationFrame(wrapProc(proc));
      },
      setTimeout(proc, delay) {
        window.setTimeout(wrapProc(proc), delay);
      }
    },
    document: {
      get() { return document; },
      body() { return document.body; },
      getElementById: Document.prototype.getElementById.bind(document),
      createTextNode: Document.prototype.createTextNode.bind(document),
      createElement: Document.prototype.createElement.bind(document)
    },
    element: {
      value(elem) {
        return elem.value;
      },
      setValue(elem, value) {
        elem.value = value;
      },
      setWidth(elem, width) {
        elem.width = width;
      },
      setHeight(elem, height) {
        elem.height = height;
      },
      appendChild(parent, child) {
        return parent.appendChild(child);
      },
      setAttribute(elem, name, value) {
        elem.setAttribute(name, value);
      },
      removeAttribute(elem, name) {
        elem.removeAttribute(name);
      },
      remove(elem) {
        elem.remove();
      },
      replaceWith(oldElem, newElem) {
        oldElem.replaceWith(newElem);
      },
      addEventListener(elem, name, proc) {
        elem.addEventListener(name, wrapProc(proc));
      },
      removeEventListener(elem, name, proc) {
        elem.removeEventListener(name, wrapProc(proc));
      },
      clone(elem) {
        return elem.cloneNode();
      }
    },
    event: {
      preventDefault(event) {
        event.preventDefault();
      },
      keyboardCode(event) {
        return event.code;
      }
    },
    canvas: {
      getContext(elem, type) {
        return elem.getContext(type);
      },
      setFillColor(context, color) {
        context.fillStyle = color;
      },
      setFont(context, font) {
        context.font = font;
      },
      setTextAlign(context, align) {
        context.textAlign = align;
      },
      clearRect(context, x, y, w, h) {
        context.clearRect(x, y, w, h);
      },
      fillRect(context, x, y, w, h) {
        context.fillRect(x, y, w, h);
      },
      fillText(context, text, x, y) {
        context.fillText(text, x, y);
      },
      drawImage(context, image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight) {
        context.drawImage(image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight);
      },
      setScale(context, sx, sy) {
        context.scale(sx, sy);
      },
      setTransform(context, a, b, c, d, e, f) {
        context.setTransform(a, b, c, d, e, f);
      },
      setImageSmoothingEnabled(context, enabled) {
        context.imageSmoothingEnabled = (enabled == 1);
      }
    },
    audio: {
      new(src) {
        return new Audio(src);
      },
      play(audio) {
        audio.play();
      },
      volume(audio) {
        return audio.volume;
      },
      setVolume(audio, vol) {
        audio.volume = vol;
      }
    },
    image: {
      new(src) {
        const img = new Image();
        img.src = src;
        return img;
      }
    }
  });
  const scheme = await mod.reflect();
  scheme.init_module(mod);
}
window.addEventListener("load", load);