Re: Sort letters

Actually, you can use STRING< for characters, symbols and strings.

 
(defun sortit (diddel dudel)
  (loop for elem in (append diddel dudel)
        if (numberp elem) collect elem into numbers
        else collect elem into alfas
        finally (return (values (sort numbers #'<) (sort alfas #'string<)))))
 
(sortit '(4 p 2 5) '(m 6 a v e))
=>
(2 4 5 6)
(A E M P V)

Gauche Scheme

(define (sortit . lists)
  (receive (n a) (partition number? (concatenate lists))
    (values
      (sort n)
      (sort-by a x->string))))

(sortit '(4 p 2 5) '(m 6 a v e) '(0 z 9) '(b 3))

  ===>
(0 2 3 4 5 6 9)
(a b e m p v z)