I didn't like this sixth stage, it copes with too much stuff to be added.
It could well be broken down into at least three stages (one for implementing string manipulation, one preparing code.c for the next stage (in the same way stage 4 was a preparation for stage 5), and a final one implementing the stack frame and function definition).

Anyway, I'm doing the exercises and implementing stuff, my hoc(1) is in stage 5 and I'm implementing string manipulations rn.

I'm also using plan9port's hoc as reference, and just found some bugs in it, lol. It is always fun to use other people's code for learning and find something wrong in it while you learn.