Thursdays are presentation days, and I have decided I want to present as often as possible, regardless of the state of my projects. I chose to present about the realisation I had that dealing with mutable files in Protagonist means making a distinction between addresses and contents that isn't usually done in filesystems.
I had wanted to draw a simple diagram of three circular nodes laid out in an equilateral triangle formation with arrows between them showing dependencies. My go-to language for this kind of problem is PostScript. I love PostScript, though I am still a novice with it. It gives fine-grained control over your drawing, and it is stack-based.
However, when I started trying to write my program, I felt rushed, and it seemed like I wouldn't have time to both write an elegant program to draw the diagram, and finish thinking through what I wanted to present before the day was over. I have written a similar diagram in the past using some Python interface to GraphViz, but I couldn't remember which one, and I spent some time looking at different such libraries, but not feeling like they gave me what I wanted.
I eventually went back to PostScript, and hacked out some ugly-but-working code to generate my diagram:
This gave me an idea about to get back into learning a stack-based language, by successively refining this code.