Eloquent Ruby

Chapter 25. Create Self-Modifying Classes

In the last chapter we looked at how you can take advantage of Ruby’s open classes to do monkey patching, to add to, modify, or even subtract from an existing class. We saw how you can get a lot of programming mileage out of this technique in the form of enhanced or repaired classes.

In this chapter we’re going to continue our look at the dynamic nature of Ruby classes, and we’ll start by asking a very fundamental question: How do Ruby classes get defined in the first place? Not only will the answer to this question illuminate how monkey patching works, but it will also enable us to build classes that can programmatically modify themselves. We will also learn how to cope with some of the common mistakes ...