anchor.diff:  (in-package :lem)
   
  -(defparameter *frame-display-map* (make-hash-table))
  +(defparameter *display-frame-map* (make-hash-table))
   
   (defstruct frame
     ;; window
  
positive.code:   (maphash (lambda (k v)
               (declare (ignore k))
               (teardown-frame v))
             *frame-display-map*))
  
  (defun redraw-frame (frame)
    (redraw-display* frame))
  
negative.code:   (minibuffer-start-charpos nil))
  
  (defun map-frame (key frame)
    (setf (gethash key *display-frame-map*) frame))
  
  (defun get-frame (key)
    (gethash key *display-frame-map*))
  
  (defun current-frame ()
    (get-frame (implementation)))
  
  (defun unmap-frame (key)
    (let ((frame (gethash key *display-frame-map*)))
      (remhash key)
      frame))
  
  