invoke a callback after all operations

after.js

function after (count, callback) {
    return function () {
        while(--count === 0) {
            console.log(arguments);
            callback.call(this, arguments);
        }
    }
}

// define some operations
function func1 () {console.log('func1 done.'); done(1);}
function func2 () {console.log('func2 done.'); done(2);}
function func3 () {console.log('func3 done.'); done(3);}

var funcs = [func1, func2, func3];
var done = after(funcs.length, function () {
    console.log('all things done!', arguments);
});

// test
funcs.forEach(function (func) {
    func();
});