ack/lang/cem/cpp.ansi/class.h

/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/* $Id$ */
/* U S E   O F   C H A R A C T E R   C L A S S E S */

/*	As a starter, chars are divided into classes, according to which
	token they can be the start of.
	At present such a class number is supposed to fit in 4 bits.
*/

#define	class(ch)	((tkclass)[(unsigned char)ch])

/*	Being the start of a token is, fortunately, a mutual exclusive
	property, so, as there are less than 16 classes they can be
	packed in 4 bits.
*/

#define	STSKIP	0	/* spaces and so on: skipped characters		*/
#define	STNL	1	/* newline character(s): update linenumber etc.	*/
#define	STGARB	2	/* garbage ascii character: not allowed		*/
#define	STSIMP	3	/* this character can occur as token		*/
#define	STCOMP	4	/* this one can start a compound token		*/
#define	STELL	5	/* wide character- or string- constant prefix	*/
#define	STIDF	6	/* being the initial character of an identifier	*/
#define	STCHAR	7	/* the starter of a character constant		*/
#define	STSTR	8	/* the starter of a string			*/
#define	STNUM	9	/* the starter of a numeric constant		*/
#define	STEOI	10	/* End-Of-Information mark			*/
#define	STMSPEC	11	/* special class for token expansion		*/

#define	NOEXPM	'\003'	/* don't expand the next macro identifier	*/
#define	TOKSEP	'\004'	/* the token separator				*/

/*	But occurring inside a token is not, so we need 1 bit for each
	class.  This is implemented as a collection of tables to speed up
	the decision whether a character has a special meaning.
*/
#define	in_idf(ch)	(inidf[(unsigned char)ch])
#define	is_oct(ch)	(isoct[(unsigned char)ch])
#define	is_dig(ch)	(isdig[(unsigned char)ch])
#define	is_hex(ch)	(ishex[(unsigned char)ch])
#define	is_wsp(ch)	(iswsp[(unsigned char)ch])

extern char tkclass[];
extern char inidf[], isoct[], isdig[], ishex[], iswsp[];