/*
 * |-----------------------------------------------------------|
 * | Copyright (c) 1991, 1990 MIPS Computer Systems, Inc.      |
 * | All Rights Reserved                                       |
 * |-----------------------------------------------------------|
 * |          Restricted Rights Legend                         |
 * | Use, duplication, or disclosure by the Government is      |
 * | subject to restrictions as set forth in                   |
 * | subparagraph (c)(1)(ii) of the Rights in Technical        |
 * | Data and Computer Software Clause of DFARS 252.227-7013.  |
 * |         MIPS Computer Systems, Inc.                       |
 * |         950 DeGuigne Avenue                               |
 * |         Sunnyvale, California 94088-3650, USA             |
 * |-----------------------------------------------------------|
 */
#ident	"$Header: bal.c,v 1.7.2.1 92/06/24 13:57:34 marker Exp $"

/*	Copyright (c) 1984 AT&T	*/
/*	  All Rights Reserved  	*/

/*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T	*/
/*	The copyright notice above does not evidence any   	*/
/*	actual or intended publication of such source code.	*/

#
/*
	Function to find the position, in str, of the first of the char-
	acters in end occurring outside a balanced string.  A balanced string
	contains matched occurrences of any character in open and the corres-
	ponding character in clos.  Balanced strings may be nested.  The null
	at the end of str is considered to belong to end.  Unmatched members
	of open or clos result in an error return.
*/

#define ifany(x) for (p=x; *p; p++) if (c == *p)
#define matching_clos clos[p-open]
#define error -1
#define position s-str-1

balbrk(str,open,clos,end)
char *str,*open,*clos,*end;
{
	register char *p, *s, c;
	char opp[2];
	opp[1] = '\0';
	for (s = str; c = *s++;  ) {
		ifany(end) return position;
		ifany(clos) return error;
		ifany(open) {
			opp[0] = matching_clos;
			s += balbrk(s,open,clos,opp);
			if (*s++ != matching_clos) return error;
			break;
		}
	}
	return position;
}
