Thank you. I remember reading “Gödel, Escher, Bach” and getting into the rabbit hole of term-rewriting. Then figured out it would be a fantastic way to build a compiler, simply by iteratively rewriting expressions into what is basically assembly code. Would also be a great framework for a modular bring-your-own-parser compiler construction kit. Going from theory to practice on how to achieve that, i.e. the best way to declaratively encode such transformations in Lisp-like language, how to deal with conflicts, ambiguity and the exponentially exploding search space eventually led me to e-graphs and some of the stuff you mention in this comment…

At which point it felt like having jumped into the deep sea, at night, and sharks are all around. I have no formal education in CS, and a lot of this stuff is way above my pay grade. Though it made me wonder why none of this stuff has hit mainstream; modern compilers are still very crude, it seems like such an obvious idea to model compilation as transformation of one graph into another. Is this just fringe academic research that hasn’t yet trickled down to the masses of us code monkeys?

I still have a soft-spot for this niche of computer science, but I need to find 5 years and 20 IQ points to understand how it all fits together.