CPSの利用(5)

GUIでの利用
    (let1 button (gtk-button-new-with-label "Start")
      (define (next val cont)
        (gtk-button-set-label button (x->string val))
        (g-signal-connect button "clicked"
                          (if cont (lambda _ (cont)) values)))
      (g-signal-connect button "clicked"
                        (lambda _
                          (finder odd? '(1 2 3 4 5) next)))