async ee

gistfile1.js

var Emitter = require('events').EventEmitter;

exports.async = function(arr, fn, done) {
  var todo = arr.length,
      em   = new Emitter();
  
  em.on('done', function() {
    if(!(--todo)) { done(); }
  });
  arr.forEach(function(item) {
    fn(item, em);
  });
};

/*
  example:

  utile.async([1,2,3], function(item, em) {
    Math.sin(item);
    em.emit('done');
  }, function() { console.log('done'); });
*/