Bernd Schiffer has published a screencast of the Prime Factors Code Kata that we prepared.
When a programmer new to TDD watches such a code kata he has the same problem that an unexperiences karate student has when he watches a karate kata. He can see what’s happening but he has no idea why.
In karate there is a second kata flavour: Bunkai:
Bunkai literally meaning “analysis” or “disassembly”, is a term used in Japanese martial arts referring to the application of fighting techniques extracted from the moves of a “form” (kata) (see Wikipedia).
When watching a kata bunkai it becomes pretty obvious why the moves of the kata are done.
The same should be possible with code katas. Therefore we tried to transfer the bunkai concept to code katas. For now that simply means that the non obvious parts of the code kata are explained. I published the result for the prime factors code kata on YouTube.
I have to confess that I simply cut Bernds video. I think the real code kata bunkai should include the explanation in the kata – like it is in karate. We will work on that.