I assume that in most array languages, you also create "words" or however you want to call functions, to reuse code. I wonder about a purely aesthetic issue: how does it look to interleave those symbols with user-defined words that by nature will be much, much longer, i.e. "create-log-entry" or "calculate-estimated-revenue".
It is a very interesting write-up. A random thought I had while reading this: I feel like long-term, a system that schedules/"optimizes" the process of learning by reading/watching content and then engaging with this new content by taking notes and connecting those notes to existing knowledge could be more fruitful. Something akin to SuperMemo's "Incremental Reading", but not as focused on creating flashcards out of the material.
With traditional Q/A-style spaced repetition, I feel like accumulating a long list of isolated facts sometimes (I know, you can remedy this a bit by also quizzing connections, context, but I feel like the general tendency still remains).
A quick question that I could not answer from reading the Github page: How married is the learning process to those "courses" you describe? If I have a topic X and start with 0 knowledge about it, could I use trane to learn it if there is no premade course yet? I assume to create a course about it, I would have to have quite some knowledge about the topic already, to be able to think of exercises and rate them in terms of difficulty/hierarchy.