Re: CC Mode - syntactical can of worms.

["Lennart Borgman (gmail)" <lennart.borgman@gmail.com>]

Alan Mackenzie wrote:
>> CC-mode's job is fundamentally impossible.
> 
> Hey, don't be like that!  ;-)  Yes, people can deliberately break it with
> the likes of HELLO and WORLD, but the more modest aim of CC Mode, to deal
> properly with anything reasonable, is doable.
> 
> I think I can fix this by setting a neutral syntax-table property on
> anything obtrusive in a CPP construct.  Here's a first shot at doing
> that:
> 
> 
> ;; Set syntax table properties on a CPP (logical) line, so that it becomes
> ;; "syntactically neutral".  This means that lines such as:
> ;;
> ;;     #warning for isn't a keyword.
> ;;                     ^
> ;; and
> ;;
> ;;     #define RBRACE }
> ;;                    ^
> ;; won't interact syntactically with the rest of the file.
> (defun c-neutralize-CPP-line (beg end)
>   (let (s)
>     (while
> 	(progn
> 	  (setq s (parse-partial-sexp beg end -1))
> 	  (cond
> 	   ((< (nth 0 s) 0)		; found an unmated ),},]
> 	    (c-put-char-property (1- (point)) 'syntax-table '(1)) ; "punctuation".
> 	    t)
> 	   ((or (nth 3 s) (nth 4 s))	; In a string or comment.
> 	    (c-put-char-property (nth 8 s) 'syntax-table '(1))
> 	    t)
> 	   ((> (nth 0 s) 0)		; In a (,{,[
> 	    (c-put-char-property (nth 1 s) 'syntax-table '(1))
> 	    t)
> 	   (t nil))))))
> 


This is like watching a game of chess - without understanding the moves, 
but knowning that the players do.