Creating an Igcse Pseudocode Interpreter

Summary

Prelude#Check out the first part of this series, of course. This article won’t feature too much on the interpreter design, but how to effectively use it to your own benefit.TL;DR, I tried to write an IGCSE pseudocode interpreter a while ago, and I finished! Find it here at https://github.com/ezntek/beancode. Or, install it directly with pip install beancode --break-system-packages (this will not break your system packages, because beancode has no system dependencies, and will not break anything despite the scary flag)Jump here if you only want to learn about the special and extra features of the interpreter and functional quirks.Intro#I published my first article almost a year ago; on the 18th of September, 2024. It is now the 13th September, 2025. What’s happened since then?Well, a lot of school stuff. I was in grade 10 at the time, with quite a bit of spare time. However, I just didn’t get around to doing much of anything!Originally I wanted to write a pseudocode compiler in C, but I got stuck at the parser. If you look at my really old code somewhere in https://github.com/ezntek/beanwarehq, I actually tried to write a bottom-up parser. Young ezntek really did discover another parsing technique just then, however implemented horribly and barely functional.I then tried to write one in Zig. In one afternoon I ported the lexer over, but that didn’t end up going anywhere. Sometime during march of this year, I just had enough waiting; I had a bunch of other projects and a lot of schoolwork to do (I am, after all, a leader of the computer programming club at my school, and the author of a bunch of IGCSE CS revision resources), but I really just wanted to get something done.I tried to follow Crafting Interpreters…in Python. I knew the language, it was slow, horrible, but great for doing hacky stuff like the thing I envisioned (just a single top-down recursive-descent parser), and that ended up going…really well.So what do we have now?…what? By the way, yes...