Kata

“7777…8?!??!“, exclaimed Bob, “I missed it again! Argh!” Every time there’s an interesting number coming up, he notices and then promptly forgets. Who doesn’t like catching those one-off interesting mileage numbers?

Let’s make it so Bob never misses another interesting number. We’ve hacked into his car’s computer, and we have a box hooked up that reads mileage numbers. We’ve got a box glued to his dash that lights up yellow or green depending on whether it receives a 1 or a 2 (respectively).

It’s up to you, intrepid warrior, to glue the parts together. Write the function that parses the mileage number input, and returns a 2 if the number is “interesting” (see below), a 1 if an interesting number occurs within the next two miles, or a 0 if the number is not interesting.

Kata

Create a function method that allow you to wrap an existing function. The method signature would look something like this:

Usage Example:

function speak(name){
   return "Hello " + name;
}

speak = speak.wrap(function(original, yourName, myName){
   greeting = original(yourName);
   return greeting + ", my name is " + myName;
})

var greeting = speak("Mary", "Kate");

Kata

Description:

This is the first part of three (part2, part3).

Generators and Iterators are new ES6 features that will allow things like this:

function* fibonacci() {
    let [prev, curr] = [0, 1];
    for (;;) {
        [prev, curr] = [curr, prev + curr];
        yield curr;
    }
}

Using them in this way, we can do amazing things:

let seq = fibonacci();
print(seq.next()); // 1
print(seq.next()); // 2
print(seq.next()); // 3
print(seq.next()); // 5
print(seq.next()); // 8

This is powerful, but until a few months later, ES6 will not be born.

The goal of this kata is to implement pseudo-generators with ES5.