18 - INHERITANCE: THE REST OF THE STORY (CONT.)

Summary

I think this was originally titled “Inheritance: The Rest of the Rest of the Story,” but it got edited. Oh well.

The pattern presented here is another in the “Transformation Series.” It recommends letting inheritance evolve from the need to reduce code duplication.

In the June issue, where I took on accessor methods, I stated that there was no such thing as a truly private message. I got a message from Nikolas Boyd reminding me that he had written an earlier article describing exactly how to implement really truly private methods. One response I made was that until all the vendors ship systems that provide method privacy, Smalltalk cannot be said to have it. Another is that I'm not sure I'd use it even if I had it. It seems like some of my best “reuse moments” occur when I find a supposedly private method in a server that does exactly what I want. I don't yet have the wisdom to separate public from private with any certainty.

On a different note, I've been thinking about the importance of bad style. In this column, I always try to focus on good style, but in my programming there are at least two phases of project development where maintaining the best possible style is the farthest thing from my mind. When I am trying to get some code up and running I often deliberately ignore good style, figuring that as soon as I have everything running I can simply apply my patterns to the code to get well-structured code that does the same thing.