FRP Bacon.js example

/*
 - generate requests on timer
 - if timer signals before request completed, then wait until request complete
 - if timer signals multiple times before request completed then issue signle
   request after getting response
 
 Example timeline

  timer:          0      1    2               2    
  request made:   r1              r2          r3   
  response:                       r1    r2         
*/

var Bacon = require('baconjs')
var timer = Bacon.interval(1000, 'timer')
timer.subscribe(() => console.log('timer', timeFrom()))
var initialTime = new Date().getTime()
var timeFrom = () => (new Date().getTime() - initialTime)/1000
function request(){
  // emulate varying response times with Math.random
  var delay = 4000*Math.random()
  console.log('mk request', delay/1000, timeFrom())
  return Bacon.later(delay, delay/1000)
}
function responses(){
  var rq = request()
  return Bacon.zipAsArray(timer.first(), rq).flatMap(val => {
    return Bacon.once(val).concat(responses())
  })
}
responses().subscribe(val => {})