Re: Tiny change to find-tag-default.

[storm@cua.dk (Kim F. Storm)]

martin rudalics <rudalics@gmx.at> writes:

> Wouldn't it make sense to rewrite the rest of `find-tag-default' too?
> In its current version it unnecessarily clobbers `match-data', requires
> a `condition-case' to handle errors in `forward-sexp', and has other
> tedious things like repeated forward-charing and re-searching.
>
> I'm using the attached version for approximately half a year and didn't
> encounter any problems so far.

Your code works fine for me too.

But I'm puzzled by the use of (forward-sexp -1) in the old code.  What
subtle effect did the author intend by using that?  Maybe to get to
the function name in a function call?  ... if that was the intention,
it doesn't seem to work.



>
> *** subr.el	Tue Jun  6 19:20:26 2006
> --- subr.el	Mon Jul 10 11:42:40 2006
> ***************
> *** 1949,1973 ****
>     "Determine default tag to search for, based on text at point.
>   If there is no plausible default, return nil."
>     (save-excursion
> !     (while (looking-at "\\sw\\|\\s_")
> !       (forward-char 1))
> !     (if (or (re-search-backward "\\sw\\|\\s_"
> ! 				(save-excursion (beginning-of-line) (point))
> ! 				t)
> ! 	    (re-search-forward "\\(\\sw\\|\\s_\\)+"
> ! 			       (save-excursion (end-of-line) (point))
> ! 			       t))
> ! 	(progn
> ! 	  (goto-char (match-end 0))
> ! 	  (condition-case nil
> ! 	      (buffer-substring-no-properties
> ! 	       (point)
> ! 	       (progn (forward-sexp -1)
> ! 		      (while (looking-at "\\s'")
> ! 			(forward-char 1))
> ! 		      (point)))
> ! 	    (error nil)))
> !       nil)))
>
>   (defun play-sound (sound)
>     "SOUND is a list of the form `(sound KEYWORD VALUE...)'.
> --- 1949,1973 ----
>     "Determine default tag to search for, based on text at point.
>   If there is no plausible default, return nil."
>     (save-excursion
> !     (let (from to bound)
> !       (when (or (and (save-excursion
> ! 		       (skip-syntax-backward "w_") (setq from (point)))
> ! 		     (save-excursion
> ! 		       (skip-syntax-forward "w_") (setq to (point)))
> ! 		     (> to from))
> ! 		;; Look between `line-beginning-position' and `point'.
> ! 		(and (setq bound (line-beginning-position))
> ! 		     (skip-syntax-backward "^w_" bound)
> ! 		     (> (setq to (point)) bound)
> ! 		     (skip-syntax-backward "w_")
> ! 		     (setq from (point)))
> ! 		;; Look between `point' and `line-end-position'.
> ! 		(and (setq bound (line-end-position))
> ! 		     (skip-syntax-forward "^w_" bound)
> ! 		     (< (setq from (point)) bound)
> ! 		     (skip-syntax-forward "w_")
> ! 		     (setq to (point))))
> !         (buffer-substring-no-properties from to)))))
>
>   (defun play-sound (sound)
>     "SOUND is a list of the form `(sound KEYWORD VALUE...)'.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk