Hello,

I have optimized the expansion of the macro whichever. In the current implementation, it generates n random values, creates O(n) functions and calls one of them. Using a sort of "inline" binary search, I was able to create an expansion which makes one call to RANDOM, O(log n) tests, and also does not create any extra function.

A test with my implementation:

cl-user> (macroexpand-1 '(whichever (list 1) (list 2) (list 3) (list 4) (list 5) (list 6) (list 7)))
(let ((#:random-number854 (random 7)))
(if (< #:random-number854 3)
      (if (< #:random-number854 1)
          (list 1)
          (if (< #:random-number854 2)
              (list 2)
              (list 3)))
      (if (< #:random-number854 5)
          (if (< #:random-number854 4)
              (list 4)
              (list 5))
          (if (< #:random-number854 6)
              (list 6)
              (list 7)))))
t

Regards,
Gustavo Henrique Milaré.