Regexp Emacs的R評論

Question

我想在Emacs中建立一個正則表達式來清理我的R代碼。

一個我遇到的問題是，有不同類型的註釋： 你有那些有一定量的空白（1），例如：

 # This is a comment: 
# This is also a comment 

，或者你有這樣的情況下（ 2）：

require(lattice) # executable while the comment is informative 

的想法是，我要對齊的意見時，他們是第二類（的東西是可執行文件後），同時排除那些第一類。

理想情況下，它將對齊第一類的所有評論，但不包括第一類評論。

例子：

funfun <- function(a, b) { 
# This is a function 
    if (a == b) { # if a equals b 
     c <- 1 # c is 1 
    } 
    } 
# 

要：

funfun <- function(a, b) { 
# This is a function 
    if (a == b) { # if a equals b 
     c <- 1  # c is 1 
    } 
    } 
# 

我發現了一個正則表達式做那些第一類的替代品，所以後來我能夠將它們對齊每個段落（mark-段）。這種工作很好。

問題是，則回代：

(replace-regexp "^\\s-+#+" "bla" nil (point-min) (point-max)) 

這代替從行的開頭，有空白的任何量和類似的註釋字符的任何量：

 ######### 

成

 bla 

問題是我想將它們重新放回原來的位置最後，所以「bla」必須回到相同數量的空白和相同數量的＃中。

希望有人能夠理解我正在嘗試做什麼，並有一個更好的方法或知道如何解決這個正則表達式部分。

​​

Answer 1

嗯，這裏是在做一些我以爲你是經過一番瘋狂的嘗試。它似乎工作，但它需要大量的測試和拋光：

(defun has-face-at-point (face &optional position) 
    (unless position (setq position (point))) 
    (unless (consp face) (setq face (list face))) 
    (let ((props (text-properties-at position))) 
    (loop for (key value) on props by #'cddr 
      do (when (and (eql key 'face) (member value face)) 
       (return t))))) 

(defun face-start (face) 
    (save-excursion 
    (while (and (has-face-at-point face) (not (bolp))) 
     (backward-char)) 
    (- (point) (save-excursion (move-beginning-of-line 1)) (if (bolp) 0 -1)))) 

(defun beautify-side-comments() 
    (interactive) 
    ;; Because this function does a lot of insertion, it would 
    ;; be better to execute it in the temporary buffer, while 
    ;; copying the original text of the file into it, such as 
    ;; to prevent junk in the formatted buffer's history 
    (let ((pos (cons (save-excursion 
        (beginning-of-line) 
        (count-lines (point-min) (point))) 
        (- (save-excursion (end-of-line) (point)) (point)))) 
     (content (buffer-string)) 
     (comments '(font-lock-comment-face font-lock-comment-delimiter-face))) 
    (with-temp-buffer 
     (insert content) 
     (goto-char (point-min)) 
     ;; thingatpt breaks if there are overlays with their own faces 
     (let* ((commentp (has-face-at-point comments)) 
      (margin 
       (if commentp (face-start comments) 0)) 
      assumed-margin pre-comment commented-lines) 
     (while (not (eobp)) 
      (move-end-of-line 1) 
      (cond 
      ((and (has-face-at-point comments) 
       commentp)   ; this is a comment continued from 
             ; the previous line 
      (setq assumed-margin (face-start comments) 
        pre-comment 
        (buffer-substring-no-properties 
        (save-excursion (move-beginning-of-line 1)) 
        (save-excursion (beginning-of-line) 
            (forward-char assumed-margin) (point)))) 
      (if (every 
       (lambda (c) (or (char-equal c ?\) (char-equal c ?\t))) 
       pre-comment) 
       ;; This is the comment preceded by whitespace 
       (setq commentp nil margin 0 commented-lines 0) 
       (if (<= assumed-margin margin) 
        ;; The comment found starts on the left of 
        ;; the margin of the comments found so far 
        (save-excursion 
        (beginning-of-line) 
        (forward-char assumed-margin) 
        (insert (make-string (- margin assumed-margin) ?\)) 
        (incf commented-lines)) 
       ;; This could be optimized by going forward and 
       ;; collecting as many comments there are, but 
       ;; it is simpler to return and re-indent comments 
       ;; (assuming there won't be many such cases anyway. 
       (setq margin assumed-margin) 
       (move-end-of-line (1- (- commented-lines)))))) 
      ((has-face-at-point comments) 
      ;; This is the fresh comment 
      ;; This entire block needs refactoring, it is 
      ;; a repetition of the half the previous blockp 
      (setq assumed-margin (face-start comments) 
        pre-comment 
        (buffer-substring-no-properties 
        (save-excursion (move-beginning-of-line 1)) 
        (save-excursion (beginning-of-line) 
            (forward-char assumed-margin) (point)))) 
      (unless (every 
        (lambda (c) 
         (or (char-equal c ?\) (char-equal c ?\t))) 
        pre-comment) 
       (setq commentp t margin assumed-margin commented-lines 0))) 
      (commentp 
      ;; This is the line directly after a block of comments 
      (setq commentp nil margin assumed-margin commented-lines 0))) 
      (unless (eobp) (forward-char))) 
     ;; Retrieve back the formatted contnent 
     (setq content (buffer-string)))) 
    (erase-buffer) 
    (insert content) 
    (beginning-of-buffer) 
    (forward-line (car pos)) 
    (end-of-line) 
    (backward-char (cdr pos)))) 

我也複製了上引擎收錄了更好的可讀性：http://pastebin.com/C2L9PRDM

編輯：這應該恢復鼠標位置，但不會恢復滾動位置（可以工作，也許，我只需要尋找如何滾動存儲）。

Answer 2

嘗試

(replace-regexp "^\\(\\s-+\\)#" "\\1bla" nil (point-min) (point-max)) 

然後

(replace-regexp "^\\(\\s-+\\)bla+" "\\1#" nil (point-min) (point-max)) 

，但如果我理解你很好，我可能會做這樣的事情：

(align-string "\b\s-#" begin end) 

Answer 3

align-regexp是Emacs的魔法真棒位你需要：

(defun align-comments() 
    "align R comments depending on whether at start or in the middle." 
    (interactive) 
    (align-regexp (point-min) (point-max) 
    "^\\(\\s-*?\\)\\([^[:space:]]+\\)\\(\\s-+\\)#" 3 1 nil) ;type 2 regex 
    (align-regexp (point-min) (point-max) 
    "^\\(\\s-*\\)\\(\\s-*\\)#" 2 0 nil))     ;type 1 regex 

前：

# a comment type 1 
     ## another comment type 1 
a=1 ###### and a comment type 2 with lots of #####'s 
a.much.longer.variable.name=2   # and another, slightly longer type 2 comment  
     ## and a final type 1 

後：

 # a comment type 1 
     ## another comment type 1 
a=1       ###### and a comment type 2 with lots of #####'s 
a.much.longer.variable.name=2 # and another, slightly longer type 2 comment  
     ## and a final type 1