HTML special char quote

gistfile1.el

(defun html-quote (str)
  (replace-regexp-in-string "[&<>]"
                            (lambda (m)
                              (or (cdr (assq (string-to-char m)
                                             '((?& . "&amp;")
                                               (?< . "&lt;")
                                               (?> . "&gt;"))))
                                  m))
                            str))