emoji.el

(defvar emoji-font
  (case window-system
    (ns "Apple Color Emoji")
    (w32 "Segoe UI")                    ;Maybe?
    (x "Symbola"))                      ;Maybe?
  "Font used to display emoji")


(defun generate-emoji-font-tables ()
  "Fetch the emoji unicode data from unicode.org, and insert
  the forms to specify that the emoji font be used for those
  codepoints into the current buffer"

  (interactive)

  (let ((buf (url-retrieve-synchronously "http://www.unicode.org/Public/emoji/2.0//emoji-data.txt")))
    (unless buf
      (error "Couldn't fetch emoji data"))

    (let ((emoji '()))
      (with-current-buffer buf
        (search-forward "\n\n") ;Skip headers

        (while (not (eobp))
          (when (looking-at "^\\([0-F]+\\)\\(\.\.\\([0-F]+\\)\\)?")
            (let* ((start (string-to-number (match-string 1) 16))
                   (end (if (match-string 3)
                            (string-to-number (match-string 3) 16)
                          nil))
                   (range (if end (cons start end) start)))
              (when (>= start #x1f000) ;Skip chars that aren't _really_
                (add-to-list 'emoji range))))
          (forward-line)))

      (insert "(progn\n")
      (dolist (e emoji)
        (insert (format "  (set-fontset-font t %s emoji-font nil 'prepend)\n"
                        (if (consp e)
                            (format "'(?\\x%x . ?\\x%x)" (car e) (cdr e))
                          (format "?\\x%x" e)))))
      (insert ")\n"))))
;; Now M-x generate-emoji-font-tables