@neauoire yaaaayyyy this is a lo-fi flavour of the Result<T> concept :) it's analogous to an Option<T> for methods (words) that might return null. I (very subjectively) find having to handle things in a balanced way like this leads to more understandable code.
https://blog.logrocket.com/understanding-rust-option-results-enums/
@klardotsh did you ever come across anything about type-checking in regards to concatenative languages by any chance? The body of work on the topic, that I can find, is extremely thin.