Interesting, thanks. I had in mind a system that would basically regex match a string and add an entry to the ledger (similar, but it would probably be a bit more flexible than the built in system).
Separately, I saw you have also worked on a similar system for food logging. That got me thinking...what else could you track with a plain text file in this format? Fitness/workout info came to mind, as well as rewards points, sleep tracking, any others? Would be cool to have a single system to track all these things, which could be linked up to APIs like Fitbit, myfitnesspal, etc.