domenic

// ES6

class AngularPromise extends Promise {
    constructor(executor) {
        super((resolve, reject) => {
            // before
            return executor(resolve, reject);
        });
        // after
    }

poetix

Iterators = (function() {
    var each, map, filter, reduce, toArray, toObject;
    
    function _map(iter, f) {
        return {
            hasNext: iter.hasNext,
            next: function() { return f(iter.next()); }
        };
    }