如何疊加文本

Question

在LaTeX文檔中，我使用\num在生成* .pdf時自動爲段落編號。我正在嘗試編寫一個函數，它將使用疊加層在Emacs中顯示數字。如果我使用一個符號我toggle-num-block功能部分的工作原理如倒三角形（例如，"\u25be"），但確實不工作時，我使用一個變量如n（這是一個數字，每個\num被發現的時間增量） 。任何關於如何做到這一點的指針將不勝感激。

要測試我的功能，我正在使用\num右側的空格來放置疊加層。如果我使用(overlay-put (make-overlay beg end) 'display "\u25be"))而不是(overlay-put (make-overlay beg end) 'display n))，則可以看到倒置的三角形。相反，倒三角形的，但是，我更願意有一個數字是逐步增加 - 1，2，3，等

我的文件看起來是這樣的：

\num Every good boy deserves fudge. 

\num I'm not a fig . . . . 

我想功能toggle-num-block能夠切換從上述例子來回下面的例子：

1.  Every good boy deserves fudge. 

2.  I'm not a fig . . . . 

這裏是我的草稿：

(require 'outline) 

(defun toggle-num-block() 
"When FLAG is non-nil, hide the region. Otherwise make it visible." 
(interactive) 
    (let ((n 0)) 
    (save-excursion 
     (goto-char (point-min)) 
     (while (re-search-forward "\\\\num" nil t) 
     (setq n (1+ n)) 
     (let* (
      (flag (not (get-char-property (match-end 0) 'invisible))) 
      (beg (match-end 0)) 
      (end (+ (match-end 0) 1))) 
      (outline-flag-region beg end flag) 
      (cond 
      (flag 
       (overlay-put (make-overlay beg end) 'display n)) ;; "\u25be" 
      (t 
       (mapc 'delete-overlay (overlays-in beg end))))))))) 

---

基於@Tyler以下（非常感謝）的有用的答案，這裏是修改後的功能，現在按預期工作：

(require 'outline) 

(defun toggle-num-block() 
"When FLAG is non-nil, hide the region. Otherwise make it visible." 
(interactive) 
    (let ((n 0)) 
    (save-excursion 
     (goto-char (point-min)) 
     (re-search-forward "\\\\begin\{document\}" nil t) 
     (while (re-search-forward "\\\\num" nil t) 
     (setq n (1+ n)) 
     (let* ((flag (not (get-char-property (match-beginning 0) 'invisible))) 
       (beg (match-beginning 0)) 
       (end (match-end 0))) 
      (outline-flag-region beg end flag) 
      (cond 
      (flag 
       (overlay-put 
       (make-overlay beg end) 
        'display 
        (concat (number-to-string n) "."))) 
      (t 
      (mapc 'delete-overlay (overlays-in beg end))))))))) 

Answer 1

你有兩個問題 - 你設置beg到match-end代替match-beginning。並且您需要將n轉換爲字符串：

(require 'outline) 
(defun toggle-num-block() 
"When FLAG is non-nil, hide the region. Otherwise make it visible." 
(interactive) 
    (let ((n 0)) 
    (save-excursion 
     (goto-char (point-min)) 
     (while (re-search-forward "\\\\num" nil t) 
     (setq n (1+ n)) 
     (let* ((flag (not (get-char-property (match-end 0) 'invisible))) 
       (beg (match-beginning 0)) 
       (end (+ (match-end 0) 1))) 
      (outline-flag-region beg end flag) 
      (cond 
      (flag 
       (overlay-put (make-overlay beg end) 
          'display (concat (number-to-string n) ". "))) 
      (t 
      (mapc 'delete-overlay (overlays-in beg end)))))))))