Eloquent Ruby

Chapter 26. Create Classes That Modify Their Subclasses

One of the fundamental principles of programming goes something like this: Never leave to a human that which can be done by a program. Or, to put it another way, some of the greatest leaps in software engineering have happened because some lazy sod simply got tired of repeating steps two through six over and over. So far in our adventures with Ruby’s open classes we have seen how we can change classes with monkey patching, a more or less manual process of slapping some new code over the existing code. From there we moved to building classes that could change themselves, classes that say “Gee, I’m running in Ruby 1.8, so I had better define this method.” In this chapter we’ll make the final ...