Seven Languages in Seven Weeks

Day 3: Serious Change

The whole point of Mary Poppins is that she made the household better as a whole by making it fun and changing the hearts of the people in it with passion and imagination. You could back off a little and play it safe, using Ruby to do the same things you already know how to do in other languages. But when you change the way a language looks and works, you can capture magic that makes programming fun. In this book, each chapter will show you some nontrivial problem that the language solves well. In Ruby, that means metaprogramming.

Metaprogramming means writing programs that write programs. The ActiveRecord framework that’s the centerpiece of Rails uses metaprogramming to implement a friendly language for building classes ...