Refactoring: Improving the Design of Existing Code

Chapter 11. Dealing with Generalization

Generalization produces its own batch of refactorings, mostly dealing with moving methods around a hierarchy of inheritance. Pull Up Field (320) and Pull Up Method (322) both promote function up a hierarchy, and Push Down Method (328) and Push Down Field (329) push function downward. Constructors are a little bit more awkward to pull up, so Pull Up Constructor Body (325) deals with those issues. Rather than pushing down a constructor, it is often useful to use Replace Constructor with Factory Method (304).

If you have methods that have a similar outline body but vary in details, you can use Form Template Method (345) to separate the differences from the similarities.

In addition to moving function around ...