hide code blocks in Markdown by outline.el

md-hide-codes.el

;; md-hide-codes.el:
;; hide code blocks in Markdown by outline.el

(require 'outline)

(defun md-hide-codes ()
  "hide code blocks in Markdown"
  (interactive)
  (save-excursion
    (goto-char (point-min))
    (let ((start-point nil))
      (while (re-search-forward "^```" nil t)
	(if (null start-point)
	    (setq start-point (point))
	  (outline-flag-region start-point (match-beginning 0) t)
	  (setq start-point nil) )))))