These are some things I'd like to add, sometime:
- Self-recursive functions should use tail call elimination (i.e., you shouldn't get a stack overflow). Other recursion doesn't need this optimization (it messes up tracebacks and other debugging).
- The way errors are handled is kind of dumb. I think it can be done much more intelligently, maybe using paste.excections or something similar.
- Keyword arguments for function calls aren't supported. This makes it hard to use lots of Python code where keywords are used heavily.