By definition, no.
https://opensource.org/osd-annotated #6
10 karma · joined February 24, 2017
The motto started out as "BASHwards-compatible", but that was unsatisfactory because on one hand it sounds like nonsense, and on the other hand, it's not actually compatible with Bash. So that devolved over time into what we have now.
https://github.com/xonsh/xonsh/blame/ebd4e597a3cf063b124e5a5... https://github.com/xonsh/xonsh/blame/82cac3fff08b5cc26e421f1... https://github.com/xonsh/xonsh/blame/bd964ce552282334c881181...
https://crystal-lang.org/api/Nil.html https://crystal-lang.org/docs/syntax_and_semantics/union_typ...