Lisp? Then I would use Lisp...
> The goal is to define a comprehensive, trivially-parsable and sugar-free syntax.
Ruby has syntax sugar, no need to remove the funny parts.
This is just an intermediate representation, it's not meant to be used directly (even though you can do that, of course).
Lisp has completely different runtime semantics. Even the lexical scope in Ruby is extremely peculiar. One of the hard parts of writing this document was to remove the intuitive influence of Lisp because it just doesn't make sense for Ruby.
Claude suggests it, but I need to learn a lot of Redex to understand how to apply it.
I have a general understanding of what operational semantics is. Or maybe, are there any Redex implementations for common programming languages? \lambda_v is a bit too abstract.