Refactoring Workbook

Chapter 4. Names

The creation of a good mental model is one of the key challenges in developing software. There are several tools people use to help with this:

• Project dictionaries

• Domain vocabularies, ontologies, languages

• XP-style metaphors

How we name things is important. Good names perform several functions:

• They provide a vocabulary for discussing our domain.

• They communicate intent.

• They support subtle expectations about how the system works.

• They support each other in a system of names.

It's hard to pick good names, but it's worth the effort. Ward Cunningham describes using a thesaurus to get just the right sense (see http://c2.com/cgi/wiki?SystemOfNames ).

Some teams have coding standards and naming standards that affect how names are chosen . I generally follow these guidelines:

• Use verbs for manipulators and nouns and/or adjectives for accessors.

• Use the same word for similar things and different words for different things.

• Prefer one-word names.

• Value communication most.

Especially with tool support, it's not that hard to change a name when you realize there's a better one. It's worth investing energy in improving names as you modify code.