ll? my-list))))
          (do-something my-list))

(define (look-up key alist)
  (and-let* ((x (assq key alist))) (cdr x)))

(or
  (and-let* ((c (read-char))
    ((not (eof-object? c))))
    (string-set! some-str i c)  
    (set! i (+ 1 i)))
  (begin (do-process-eof)))

			; A more realistic example
                        ; Parse the 'timestamp' ::= 'token1' 'token2'
                        ;   token1 ::= 'YY' 'MM' 'J'
                        ;   token2 ::= 'GG' 'gg' "/"
(define (parse-full-timestamp token