WASM Function

<!doctype html>
  <title>WASM Test</title>
  <script>
    fetch('https://cdn.rawgit.com/guybedford/wasm-intro/f61eb0d0/1-loading-wasm-fn/test.wasm')
    .then(res => {
      if (res.ok)
        return res.arrayBuffer();
      throw new Error(`Unable to fetch WASM.`);
    })
    .then(bytes => {
      return WebAssembly.compile(bytes);
    })
    .then(module => {
      return WebAssembly.instantiate(module);
    })
    .then(instance => {
      window.wasmSqrt = instance.exports.sqrt;
    });
  </script>

(module
  (export "sqrt" (func $sqrt))
  (func $sqrt
    (param $num f32)
    (result f32)
    (f32.sqrt (get_local $num))
  )
)