Thanks... that is a good idea. I think what I might do is this:

Have a @code_lines array keep track of each line of code as the user enters it. This would allow me to implement a save command where the user can save their code to a file for later use. I'd need to pop values off of @code_lines for every undo command.

Have a new subs command that retrieves everything that looks like a subroutine definition from @code_lines and prints out their contents.