I was sick last week, and in my drug- and virus-induced haze of incoherence, the idea that I should write a Scheme interpreter in assembly language came to mind. I cannot explain from where, but there it was. So I started looking into it, wondering if I still had it in me to dig into a computer problem and get it done. I’ve been feeling a bit burned out on different aspects of the IT world, and I was thinking maybe that getting back to the basics of computer science might help. The course that I remember mostly vividly (not fondly: vividly, like in nightmares) was my Programming Languages class, where I wrote a Scheme interpreter in (wait for it, wait for it…) Scheme. It was hard, really hard. But I was also young and stupid. I don’t think it would be so hard now.
I suspect another idea was floating in my mind, which came from this article. Functional Programming is part of the solution to the multi-core problem, which is the most pressing problem facing computer science to ensure continued growth in computer capabilities. Things written the functional way self-decompose into parallelizable threads of execution, which is good in a future where lots of small processors are available instead of a few huge ones. It’s an open question if “continued growth in computer capabilities” is really a useful thing. My work with Entuura argues, “no, smaller embedded devices will deliver more social good”. But better to plant mango stones in all types of soil anyway.
So I started looking into what it would take write a Scheme interpreter in assembly and ran across An Incremental Approach to Compiler Construction [PDF]. Which is something else entirely, a guided tour into the world of compilers, where you write a compiler for Scheme in Scheme, resulting in native x86 code that evaluates Scheme expressions. Since I never actually did a compiler class, this was even better. It would scratch my itch to get back into functional programming, as well as taking me on a guided dip into the waters of assembly, but letting me program my assembly in Scheme, which I prefer anyway.
I’ve completed chapters 1 and 2 of the tutorial. This is my way of publically stating that I’ll make it through the rest of the chapters. Feel free to poke me later and ask how it went!