[kazinator]

> What's it like inheriting a lisp code base, finding out its full of homemade macros like list comprehensions, and that they're not documented?

If such a macro is used in more than two places, it's generally a relief that the author did that instead of doing copy and paste by hand.

The author had some coding idea, and formalized it into a little robot that writes that idea, which has a name.

Even if that thing isn't accompanied by documentation, it can serve as a kind of documentation to what it's doing.

Code is going to be full of homemade functions that are not documented; whether they are functions that write code at compile time, or whether they are run-time functions, is kind of a minor concern.