; Load the guessing game for its utiltities.
(load "/home/rebelsky/Web/Courses/CS151/2006F/Examples/guessing-game.scm")

(define sequential-guess-name
  (lambda ()
    ; Remember the length of the vector
    (let ((len (vector-length names)))
      ; In the kernel, we step through the positions, guessing each one
      ; in turn.
      (letrec ((kernel
                (lambda (lb ub)
                  (if (> lb ub)
                      (print-line "You win!  I've run out of names.")
                      (let* ((mid (quotient (+ lb ub) 2))
                             (midname (vector-ref names mid)))
                        (cond 
                          ((yes-or-no? (string-append "Is the name "
                                                      midname
                                                      "?"))
                           (print-line "I win!"))
                          ((yes-or-no? (string-append "Does the name alphabetically precede " midname "?")) (kernel lb (- mid 1)))
                          (else (kernel (+ mid 1) ub))))))))
        (print-line "Think of a name and I'll try to guess it.")
        (kernel 0)
        (if (yes-or-no? "Play again?")
            (sequential-guess-name)
            (print-line "Thanks for playing."))))))