Hi! Author here. We are actually planning on removing those literals and allowing applications to extend Roto with their own literals [0]. They should do so with care of course, because indeed adding more literals adds some edge cases. Most applications should be able to get by without any special literals though.

[0]: https://codeberg.org/NLnetLabs/roto/pulls/358

Nice! That sounds like a good change. I'll try to dive a bit deeper through docs once I find some time :)