Hi Maxime, I believe that match conflating () and #nil is the right thing, even if the current implementation does it unintentionally.
Those two values should be considered "the same" in most situations even though (eqv? #nil '()) is false. In fact I think they should be equal? to each other. It feels wrong that (equal? '(foo . #nil) '(foo . ())) evaluates to false, even though both arguments represent the list '(foo). Please note that #nil is not ever supposed to be used intentionally. It's there purely as an Elisp compatibility trick, and the only time Scheme could should receive it is when receiving data generated by Elisp code. For instance when Elisp code generates a list, it would be terminated by #nil. (Which is why I think it should equal? '().) Does that make sense to you? I'm not sure what the Guile maintainers would say about (equal? #nil '()). - Taylan
