获取buffer下的一个单词，不支持中文

(defconst not-symbol-chars "^a-zA-Z0-9_-")
(defconst symbol-chars "a-zA-Z0-9_-\\cc")

(defun chars-start()
  (let ((regexp-chars (concat "[" not-symbol-chars "]")) )
    (re-search-backward regexp-chars nil t)
    (char-forward)
    (point)))

(defun chars-end()
  (let ((regexp-chars (concat "[" not-symbol-chars "]")) )
    (re-search-forward regexp-chars nil t)
    (char-backward)
    (point)))

(defun char?()
  (let ((regexp-chars (concat "[" symbol-chars "]")) )
    (set-buffer (get-buffer-create "temp"))
    (looking-at regexp-chars)))

(defun test-point()
  (set-buffer (get-buffer-create "temp"))
  (buffer-substring-no-properties (chars-start) (chars-end)) )

(defun char-backward ()
  (cond ((<= (point) (point-min)) nil)
 ((char?) t)
 ((goto-char (- (point) 1))
      (char-backward))))

(defun char-forward ()
  (cond ((>= (point) (point-max)) nil)
 ((char?) t)
 ((goto-char (+ (point) 1))
      (char-forward))))

(defun get-word ()
(test-point)
)