Queuing Deferred Tasks

queue.js

var Queue = function () {
    var previous = new $.Deferred().resolve();
  
    return function (fn, fail) {
        return previous = previous.then(fn, fail || fn);
    };
};

usage.js

var queue = Queue();
var values = [...];

values.forEach(function (value) {
    queue(function () {
        return $.post('/', value);
    });
});