🚀 go-pugleaf

> >       static const char upmap [] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
> ... 
> > by introducing upmap, we can now write
> > 	upmap [ expr % (sizeof upmap / sizeof *upmap) ]
> 
> [But if] upmap is declared as upmap[] (without specifying the
> size as 26), then sizeof upmap == 27.

Clashing features!  One could fix it this way:

	#define UPMAP "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	static const char upmap [sizeof UPMAP - 1] = UPMAP;
	#undef UPMAP
	...
	upmap [ expr % (sizeof upmap / sizeof *upmap) ]
	...

I no longer remember enough of the original context to know whether
the use of % is in fact safe and sensible here.
-- 
Mark Brader                     "A moment's thought would have shown him,
msb@sq.com                       but a moment is a long time and thought 
SoftQuad Inc., Toronto           is a painful process." -- A. E. Housman

My text in this article is in the public domain.