[lukego]

I really enjoy Common Lisp being imperative enough to make iteration and collection orthogonal. You can freely mix-and-match functions for traversing data structures (dohash, maphash, etc) and ways to accumulate values (setf, push, ext:collect, etc.) I find that equivalent purely functional code often needs more functions to both traverse and collect at the same time e.g. fold, map, flatmap, etc.

I know that the functional universe has solutions to these problems, like the State monad and reusable collections protocols based on common minimal primitives, but I really appreciate being able to just freely string together tokens like DOLIST WHEN EXT:COLLECT without any elaborate frameworks.

So I suppose that programming in Common Lisp makes me appreciate non-functional programming.

Having said that, I do feel like a caveman every time I spend brain cycles on picking between EQ/EQL/EQUAL/EQUALP/STRING= or worrying about whether the object I'm updating might come from a quoted constant and invite undefined behaviour. Hard to have it all...

[ska]

I would far rather have CL's explicit representation of the different types of equality, than many languages approach of either a) "you can't do that" or b) just getting it wrong sometimes. So I would hardly call that behind the times, although the interface could be nicer I suppose.