I was asked about my code so I wanted to mention something for anyone interested in revising or using my code. Most of the code is somewhat ordered and cleaned up, but there is a lot of file ordering, selection and removing some pieces that are not very important that I have to do. It will take me a few days as I am travelling, so I get some time I will make the code more readable and specify how and why I did it like that. Also, this is my first attempt in using genetic programs, so some parts may not be as efficient as they could be. For more complex fitness functions, using more generations or a larger population you might have to do some rewriting of the code. If you do something with the code and want to share let me know :).

Thanks a lot for the feedback! I like your blog post about metaprogramming and will look more into it.