Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!cornell!batcomputer!pyramid!markhall
From: markhall@pyramid.pyramid.com (Mark Hall)
Newsgroups: comp.lang.c
Subject: nested comments
Summary: why not?
Message-ID: <13423@pyramid.pyramid.com>
Date: 19 Jan 88 21:14:33 GMT
Reply-To: markhall@pyramid.UUCP (Mark Hall)
Organization: Pyramid Technology Corp., Mountain View, CA
Lines: 40

I have a brief observation about comment operators, which applies
to C as well as other languages.  Rather than suggest that it be 
incorporated into ANSI C, I would only like to hear your views, and 
either (a) build up some ground swell of support, or (b) discover why 
it is a bad idea.

If it has been discussed before, please refer me to the article numbers.

I would like to give two short arguments for having nested comments.

	1. it is often convenient to `comment-out' code that already
	   has comments in it, either because you don't want to RUN the code,
	   or because you don't want to COMPILE the code.  If you don't want to
	   run the code, you can encircling it like:
		if  (FALSE) {
			. . . offending code with comments . . .
		}
	   but this means that the `offending code' must be syntactically
	   correct, or the compiler will not produce an executable (even
	   though the code cannot be executed), so we cannot use this method
	   when we don't want to compile the offending code.  (Note that having 
	   nested comments here would aid appreciably in performing the 
	   `binary bug hunt'.)

	2. using nested comments, you are much less likely to suffer from
	   mistakes of the form:
		a=b; 	/* <-- comment starts here
		c=d;	/* comment ends here --> */
	   The compiler would, in all likelyhood, run til EOF looking for the 
	   matching comment and, since it knows which begin-comment it is
	   trying to match, could point back to the offending comment above
	   and report ``no close comment found matching this fellow''.

Please send useful comments to:
	{seismo|sun|decwrl|hplabs|lll-lcc|ut-sally|amdahl}!pyramid!markhall
flames to:
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*******
Mark Hall - 
#include <std_disclaimer.h>