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From: ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe)
Newsgroups: comp.lang.c
Subject: Re: Is there a good example of how toupper() works?
Message-ID: <4249@goanna.cs.rmit.oz.au>
Date: 12 Nov 90 12:58:59 GMT
References: <11021@hubcap.clemson.edu> <152580@felix.UUCP> <1990Nov12.040933.5419@sq.sq.com>
Organization: Comp Sci, RMIT, Melbourne, Australia
Lines: 16

In article <1990Nov12.040933.5419@sq.sq.com>, msb@sq.sq.com (Mark Brader) writes:
> 	#  define IS_CTYPABLE(c) (((c) < UCHAR_MAX && (c) >= 0) || (c) == EOF)

Knowing that EOF is -1, one could do this with one evaluation of (c)
-- always a courteous thing to do in a macro --
	# define IS_CTYPABLE(c) \
	((unsigned)((c)+EOF) < (unsigned)(UCHAR_MAX+EOF))

I've never used isascii() myself because I had always constructed the
program so that I knew the codes were in range without needing a run-
time test; if you've got something you _think_ is a character and it's
outside the range that the ctype macros can handle what can you do but
report an error, and why leave it that late to check?
-- 
The problem about real life is that moving one's knight to QB3
may always be replied to with a lob across the net.  --Alasdair Macintyre.