Elisp macros to clear LaTeX code

Question

Does anyone know some good elisp macros for cleaning LaTeX code?

I do a lot of LaTeX editing from other sources, and I would like to expand my set of cleaning tools, since not everyone organizes their code the way I like; -)

In particular, it would be interesting to run the function X in the buffer and get all LaTeX environments (\ begin {...} and \ end {...} pairs) to sit on their own lines, this helps readability of the code.

I could try this myself, but would like to hear suggestions for best practices for programming such a function, for example. he should, of course, not enter blank lines.

offers?

Edit: for archives, here is my current version based on the answer (assuming the use of auctex). It more or less matches my needs at the moment. I added the y-or-n test to be able to detect corner cases that I did not think about.

(defun enviro-split () "Find begin and end macros, and put them on their own line." (interactive) (save-excursion (beginning-of-buffer) ;; loop over document looking for begin and end macros (while (re-search-forward "\\\\\\(begin\\|end\\)" nil t) (catch 'continue ; if the line is a pure comment, then goto next (if (TeX-in-commented-line) (throw 'continue nil) ) ;; when you find one, back up to the beginning of the macro (search-backward "\\") ;; If it not at the beginning of the line, add a newline (when (not (looking-back "^[ \t]*")) (if (y-or-np "newline?") (insert "\n") ) ) ;; move over the arguments, one or two pairs of matching braces (search-forward "{") ; start of the argument (forward-char -1) (forward-sexp) ; move over the argument (if (looking-at "[ \t]*{") ; is there a second argument? (forward-sexp) ) ; move over it if so (if (looking-at "[ \t]*\\[") ; is there a second argument? (forward-sexp) ) ; move over it if so (when (looking-at (concat "[ \t]*" (regexp-quote TeX-esc) "label")) (goto-char (match-end 0)) (forward-sexp) ) (if (looking-at (concat "[ \t]*%" )) (throw 'continue nil) ) ;; If there is anything other than whitespace following the macro, ;; insert a newline (if (not (looking-at "\\s *$")) ;;(insert "\n") (if (y-or-np "newline (a)?") (insert "\n") ) ) ) ; end catch 'continue ) (LaTeX-fill-buffer 'left) ) ) 

Answer 1

Perhaps you may be working with one regex and replace regexp for this. However, I find that the logic of these manipulations becomes quite hairy, especially if you want to consider various edge cases. In your example, you need to deal with some environments that take one argument, while others take two. I think it’s easier to combine a number of simple regular expressions with basic text editing commands:

 (defun enviro-split () "Find begin and end macros, and put them on their own line." (interactive) (save-excursion (beginning-of-buffer) ;; loop over document looking for begin and end macros (while (re-search-forward "\\\\\\(begin\\|end\\)" nil t) ;; when you find one, back up to the beginning of the macro (search-backward "\\") ;; If it not at the beginning of the line, add a newline (when (not (looking-at "^")) (insert "\n")) ;; move over the arguments, one or two pairs of matching braces (search-forward "{") ; start of the argument (forward-char -1) (forward-sexp) ; move over the argument (if (looking-at "\\s *{") ; is there a second argument? (forward-sexp)) ; move over it if so ;; If there is anything other than whitespace following the macro, ;; insert a newline (if (not (looking-at "\\s *$")) (insert "\n"))))) 

This approach has the advantage of using Emacs built-in functions to move around sexps, which is much easier than coming up with your own regular expression that can handle multiple, potentially nested expressions inside curly braces.