Smart split for Emacs

init.el

(defun smart-split ()
  "Split the frame into 80-column sub-windows, and make sure no window has
   fewer than 80 columns."
  (interactive)
  (cl-lables ((smart-split-helper (lambda (w)
                (if (> (window-width w) (* 2 81))
                  (let ((w2 (split-window w 82 t)))
                    (smart-split-helper w2))))))
    (smart-split-helper nil)))

(smart-split)