If it's impossible to follow, that code is bad.
What is reasonable code? In an article on The Whiteboard, a fellow software developer under the pen name “Jimmy Hoffa” thinks about reasonability as a measure of code quality. He arrives at six exemplary properties of reasonable code:
- small scope
- short stacks
- explicit data use
- explicit data ownership
- explicit outputs
- dictating instead of deciding
He makes a good case for continuous self-improvement and a focus on code quality in our development process. It is well worth the read, especially for beginning professionals. And not quite by chance, it seems to be a subtle advertisement for functional programming and static typing: anything else would have a hard time meeting his characteristics of reasonable code.