JavaScript: Objects, Inheritance, Privacy and Stuff

functions.js

function fairy (luckyNumber) {
    return {
        toString: function () {
            return "The number you're looking for is " + luckyNumber;
        }
    };
}

function wizard (luckyNumber) {
    var that = fairy (luckyNumber);
    that.test = function (myNumber) {
        return myNumber === luckyNumber;
    };
    return that;
}

// shared secrets

function gizmo (id, secret) {
    secret = secret || {};
    secret.id = id;
    return {
        toString: function () {
            return "gizmo " + secret.id;
        };
    };
}

function hoozit (id) {
    var secret = {}; /* final */
    var that = gizmo(id, secret);
    that.test = function (testId) {
        return testId === secret.id;
    };
    return that;

// super methods

memoizer.js

function memoizer(memo, formula) {
    var recur = function (n) {
        var result = memo[n];
        if (typeof result !== 'number') {
            result = formula(recur, n);
            memo[n] = result;
        }
        return result;
    };
    return recur;
}
var factorial = memoizer([1, 1], function (recur, n) {
    return n * recur(n - 1);
});

var fibonacci = memoizer([0, 1], function (recur, n) {
    return recur(n - 1) + recur(n - 2);
});

recurring.js

(function () {
    setTimeout(function recurring () {
        // do something and call ajax
        $('#info').load('something.php', function () {
            setTimeout(recurring, 1000);
        });
    };
})();

$(function () {
    var ul = $('ul');
    var i = 0;
    
    // pass named function into setTimeout so that it can be called again
    // when ajax call is complete
    setTimeout(function getDate() {
        var started = new Date();
        var i = index;

        index++;

        $.get('/home/date', function (date) {
            var end = new Date();
            ul.append('<li>Request #' + i + ' started at ' + started.getHours() + ':' + started.getMinutes() + ' and ended ' + end.getHours() + ':' + end.getMinutes() + '</li>');
            // ajax is complete so we call the setTimeout again
            setTimeout(getDate, 2000);
        }
    }, 2000);
}