[diekhans]

Hard rules are the problem. There is a lot of "it depends."

After over 40 years of programming, I continue to reduce the size of functions and find it easier to write and understand when I return to them. Ten lines are now a personal guideline.

However, a linear function with only tiny loops or conditionals can be easily understood when hundreds of lines are long, but not so much with nested conditionals and loops, where there is natural decomposition into functions.

I observed that the same guidelines became rules problems when test coverage became popular. They soon became metrics rather than tools to think about code and tests. People became reluctant to add sanity check code for things that could should never happen because it brought down code coverage.

[asdff]

There are certainly functions written too cleverly to be apparent how they manage to work at all in a few lines. By my own hand six months ago sometimes. The solution is an unsexy one but always works: write a books worth of comments near that function code that explains absolutely everything and why it was done.