Recursive minimalism ✍️

I read somewhere (gopher?) about ed, the line-oriented text editor. I'd never used it, but I did use edlin which was in the same vein. So I thought: learn a minimalist tool by using it to write a clone of itself. I'm not sure this is a sensible use of my time, but I enjoyed it.

Did I learn anything?

Using a line-oriented editor made me think a lot more about the mechanics of editing. I normally use a GUI editor where it's easy to jump around and make related changes. In ed I had to stop and think about how to make the changes, and not just about what needed changing. It was slow.

Parsing the input was the hard part. The input for ed seems simple, but there's an awful lot of variations and edge cases. I never learned how to do parsers/lexers, so I assume that I made a naive attempt at something I don't really understand. I considered a metric tonne of unit tests, but meh, I'm doing this for amusement only.

Having got some things working, I felt the weight of the 80/20 rule. I've had some fun getting it kind-of working, but completion is far off still, and the fun tails off quickly.

I learned more about ed than I would have done any other way. I dived in and used it, but also I was forced to read up on the details of the command syntax.

I learned why people stopped using line-oriented editors as soon as full screen editors appeared. What am I saying? I already knew this!

I remembered that I hate basic regexes, but this time I had to figure how to translate them to extended regexes (so I could actually use them in the target language) and that made me hate them more.

back to gemlog