Can #define `token-string' be empty?

[Marcus Hand]

> Is
>	#define x
> valid?

Oh yes, very much so.  It is very useful for controlling conditional
compilation, eg the inclusion or exclusion of debugging and trace code:

	#define	DEBUG
	.
	.
	.
	#ifdef DEBUG
		fprintf(stderr,"Variable is %d\n",Variable);
	#endif

It can also be set on the compilation command line (and inside makefiles
of course) like this:

	cc .... -DDEBUG ....

	Hope this helps,

		marcus hand