anchor.diff:              :sources (list (make-instance 'resume-prompt-source)))))
       (when old-prompt
         (prompter:resume old-prompt)
  -      (show-prompt-buffer old-prompt)
         (wait-on-prompt-buffer old-prompt))))
  
positive.code:            (ps:lisp input))))
    (update-prompt-input prompt-buffer input))
  
  (defun wait-on-prompt-buffer (prompt-buffer)
    "Block and return PROMPT-BUFFER results."
    (when (prompt-buffer-p prompt-buffer)
      (calispel:fair-alt
        ((calispel:? (prompter:result-channel prompt-buffer) results)
         (hide-prompt-buffer prompt-buffer)
  
negative.code:                                               :window (current-window)
                                                :result-channel (make-channel)
                                                :interrupt-channel (make-channel))))))
             (calispel:! prompt-object-channel prompt-buffer))))
        (let ((new-prompt (calispel:? prompt-object-channel)))
          (wait-on-prompt-buffer new-prompt)))))
  