Stack safe list operations

[crusso]

Many of the List operations still have naive, non-tail recursive implementations that could blow the stack. Should we fix them?

[matthewhammer]

I think that lists are naive, so having a naive implementation seems fine to me. Open to other positions too.

FWIW, I have been using binary trees instead:

• For long sequences that
• permit insertion and removal at both ends and
• efficient random access anywhere.

All of that is realistic, and none of it is (or should be) supported by List.