event_loop_remixed.js

/*

This is a simplified sample of an idea I had today inspired by the fab
project. Event loops currently suck... so I've built this wonky DSL for you.

I'll release a real library later that actually implements some not so easy
things.

*/

(function() {
  var loops;

  loops = {};
  window.loop = loop;

  function loop(name) {
    var L, table, queue;
    if (loops[name]) return loops[name];
    table = {};
    queue = [];
    L = function() {
      while (queue.length > 0) {
        L.call.apply(this,queue.shift());
      }
      return L;
    };
    L.def = function(name, fn) {
      table[name] = fn;
      return L.def;
    };
    L.def.then = L;
    L.call = function(name) {
      table[arguments[0]].apply(this, Array.prototype.slice.call(arguments, 1));
      return L.call;
    };
    L.call.then = L;
    L.cast = function() {
      queue.push(arguments);
      return L.cast;
    };
    L.cast.then = L;
    L.run = L;
    loops[name] = L;
    return L;
  }

})();

var demo = loop("demo");

demo.def
  ("show", print) // replace this with whatever you use to show stuff
  ("count_down", function(y) {
    if (y < 0) {
      demo.call("finish");
    } else {
      demo.cast
        ("show", y)
        ("count_down", y - 1);
    }
  })
  ("finish", function() {
    demo.call("show", "Done");
  })
.then.cast
  ("count_down", 42)
.then.run();