Fulfilling all function arguments in order before invoking

Question

I\'m trying to understand how the following zip function (esp. the invoke function) can be made more functional. The issue I\'ve got is that the invoke method has to wait fo

Answer 1

I don't see why do you want to make your code more functional. Nevertheless I did improve upon your zip function by removing the invoke function entirely. You really don't need it:

function zip(a, b, callback) {
    var left = [], right = [];

    a.forEach(function (value) {
        if (right.length)
            callback([value, right.shift()]);
        else left.push(value);
    });

    b.forEach(function (value) {
        if (left.length)
            callback([left.shift(), value]);
        else right.push(value);
    });
}

See the output for yourself: http://jsfiddle.net/Tw6K2/

The code is more imperative than functional. However I doubt it gets any better than this.