In both these implementations, ‘until’ is still a pre-condition loop
(same as ‘while’, but with the condition negated).
However, in many languages that have an ‘until’ loop as a language
construct, it is a post-condition loop. The body is executed first,
then the condition is evaluated.
Elisp already has the loop macro from CL which implements all of this, and more. I honestly don't understand what this discussion is all about.
Since the desired functionality is already available, why try to define a new API that won't do as much?
Regards,
Elias