Earlier quoted context omitted.
You don't need a language to be a LISP in order for them to be able to interpret themselves. There are several Java interpreters which can interpret themselves, for example.
Not sure, but I think I read recently (maybe in the Rebol docs) that it is also a homoiconic language. And I think I also read that Rebol programs can interpret chunks of Rebol code passed to them.
A Python Interpreter Written in Python (2016)
41–42 of 42 posts
Re: A Python Interpreter Written in Python (2016)
#42I found this code very useful. I've been spelunking in CPython and mostly I understand it, and can find my way around. But ceval.c is another beast entirely, being full of macros and gotos, not to mention being 5000 lines long. The interpreter loop starts here: https://github.com/python/cpython/blob/master/Python/ceval.c... So I appreciate seeing the algorithm laid out in Python. In particular it clarifies that there…
There are some changes to ceval in 3.8 that should make it a bit simpler: The interpreter loop has been simplified by moving the logic of unrolling the stack of blocks into the compiler. The compiler emits now explicit instructions for adjusting the stack of values and calling the cleaning up code for break, continue and return. Removed opcodes BREAK_LOOP, CONTINUE_LOOP, SETUP_LOOP and SETUP_EXCEPT. Added new opcodes…
Wow thanks for the pointer! This is great. I want to move more stuff to compile-time, like name resolution, and moving some control flow to compile time is something I've also wondered about.
I watched a few talks [1] about how C++ exception handling works, and they try to avoid branches/setup blocks in the "happy path". It works a little like longjmp() in C, where you just set the instruction pointer say three function calls down in the stack. But then you have to look up all the exception handlers to run in precomputed tables (which doesn't happen in C). So I wonder if something like that would speed up (my subset of) Python, since exceptions are quite common.