Example of a async-oriented monadic main function for javascript

async-main-fn.ts

async function raf<T> (f: (t: T) => Promise<T>, t: T): Promise<T> {
  return new Promise(res => requestAnimationFrame(_ => res(f(t)))) as Promise<T>
}

async function forever<T> (f: (t: T) => Promise<T>, t: T): Promise<T> {
  return await f(t).then(t1 => forever(f, t1))
}

async function update (state: T): Promise<T> {
  // Your update logic here
  // Your render logic here
  return Promise.resolve(state)
}

async function main (state: T): Promise<T> {
  // Your functions, async or otherwise here
  return forever(raf.bind(null, update), state)
}

main(initialState)

Please note, as of the initial publication of this gist, you must target es6 with typescript in order to have native support for Promse, arrow functions and async functions.