如何在不移动游标的情况下测试语法条件？

Question

我一直无法想出一种方法来测试语法条件而不移动游标-例如，skip-syntax-forward和skip-chars-forward都移动游标以返回t或正值。如何在不移动光标的情况下返回t或nil？

(defun lawlist-kill-word ()
  "Mark word / symbol + whitespace to the right of the cursor, and kill same."
  (interactive)
  (let* (
    (symbol-regexp "\\s.\\|\\s_")
    (word-regexp "\\sw"))
    (modify-syntax-entry ?' "_") ;; apostrophe = symbol constituent
    (cond
      ((< 0 (skip-syntax-forward "_."))
        (let ((end (point)))
          (set-mark end)
          (while (looking-back symbol-regexp)
            (backward-char))
          (let ((beg (point)))
            (delete-region beg end)
            (setq beg (point))
            (cond
              ((skip-chars-forward " \t")
              (setq end (point))
                (set-mark end)
                (delete-region beg end))))))
      ((< 0 (skip-syntax-forward "w"))
        (let ((end (point)))
          (set-mark end)
          (while (looking-back word-regexp)
            (backward-char))
          (let ((beg (point)))
            (delete-region beg end)
            (setq beg (point))
            (cond
              ((skip-chars-forward " \t")
              (setq end (point))
                (set-mark end)
                (delete-region beg end))))))
      (t
        (let ((beg (point)))
          (set-mark beg)
          (skip-chars-forward " \t")
            (let ((end (point)))
              (delete-region beg end)))
          (deactivate-mark)))
    (modify-syntax-entry ?' "w") ))  ;; apostrophe = word constituent

编辑：lawlist-kill-word是一项正在进行的工作--对该函数的任何更新都将发布到与该问题相关的线程中，即：Emacs: delete whitespaces or a word。

Answer 1

正如@Tobias所说:在save-excursion中包装光标移动。将您想要的任何值(例如(point))保存在变量中，并根据需要返回它们。

例如，如果您想要前面的位置有四行，请执行如下操作：

(let ((posn  (save-excursion (forward-line 4) (point))))
  posn)