swap window split

Someone give me this function. 改变两个窗口的水平垂直平铺格局

(defun swap-window-split () "If the current frame has just two windows, then replace a vertical split with a horizontal split, or vice-versa. Otherwise do nothing." (interactive) (let ((root-window (car (window-tree)))) (if (windowp root-window) (message "There's just one big window") (let ((w1 (elt root-window 2)) (w2 (elt root-window 3))) (if (or (not (windowp w1)) (not (windowp w2))) (message "Not a simple split") (let ((b1 (window-buffer w1)) (b2 (window-buffer w2))) (delete-other-windows w1) (if (car root-window) (split-window-horizontally) (split-window-vertically)) (other-window 1) (set-window-buffer (selected-window) b2))))))) (global-set-key (kbd "<f6>") 'swap-window-split)