290 lines
7.6 KiB
C
290 lines
7.6 KiB
C
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/********************************************
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rexp3.c
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copyright 1991, Michael D. Brennan
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This is a source file for mawk, an implementation of
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the AWK programming language.
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Mawk is distributed without warranty under the terms of
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the GNU General Public License, version 2, 1991.
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********************************************/
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/*$Log: rexp3.c,v $
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/*Revision 1.1.1.1 1993/03/21 09:45:37 cgd
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/*initial import of 386bsd-0.1 sources
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/*
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* Revision 3.5 92/01/21 17:33:20 brennan
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* added some casts so that character classes work with signed chars
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*
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* Revision 3.4 91/10/29 10:54:09 brennan
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* SIZE_T
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*
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* Revision 3.3 91/08/13 09:10:18 brennan
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* VERSION .9994
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*
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* Revision 3.2 91/06/10 16:18:17 brennan
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* changes for V7
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*
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* Revision 3.1 91/06/07 10:33:28 brennan
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* VERSION 0.995
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*
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* Revision 1.4 91/05/31 10:56:32 brennan
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* stack_empty hack for DOS large model
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*
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*/
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/* match a string against a machine */
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#include "rexp.h"
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extern RT_STATE *RE_run_stack_base;
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extern RT_STATE *RE_run_stack_limit ;
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extern RT_STATE *RE_run_stack_empty ;
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RT_STATE *RE_new_run_stack() ;
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#define push(mx,sx,ssx,ux) if (++stackp == RE_run_stack_limit)\
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stackp = RE_new_run_stack() ;\
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stackp->m=mx;stackp->s=sx;stackp->ss=ssx;stackp->u=ux;
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#define CASE_UANY(x) case x + U_OFF : case x + U_ON
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/* returns start of first longest match and the length by
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reference. If no match returns NULL and length zero */
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char *REmatch(str, machine, lenp)
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char *str ;
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VOID *machine ;
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unsigned *lenp ;
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{ register STATE *m = (STATE *) machine ;
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register char *s = str ;
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char *ss ;
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register RT_STATE *stackp ;
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int u_flag ;
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char *str_end, *ts ;
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/* state of current best match stored here */
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char *cb_ss ; /* the start */
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char *cb_e ; /* the end , pts at first char not matched */
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*lenp = 0 ;
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/* check for the easy case */
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if ( (m+1)->type == M_ACCEPT && m->type == M_STR )
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{ if ( ts = str_str(s, m->data.str, m->len) ) *lenp = m->len ;
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return ts ;
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}
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u_flag = U_ON ; cb_ss = ss = str_end = (char *) 0 ;
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stackp = RE_run_stack_empty ;
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goto reswitch ;
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refill :
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if ( stackp == RE_run_stack_empty )
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{ if ( cb_ss ) *lenp = cb_e - cb_ss ;
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return cb_ss ;
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}
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ss = stackp->ss ;
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s = stackp-- -> s ;
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if ( cb_ss ) /* does new state start too late ? */
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if ( ss )
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{ if ( cb_ss < ss ) goto refill ; }
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else
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if ( cb_ss < s ) goto refill ;
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m = (stackp+1)->m ;
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u_flag = (stackp+1)->u ;
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reswitch :
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switch( m->type + u_flag )
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{
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case M_STR + U_OFF + END_OFF :
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if ( strncmp(s, m->data.str, SIZE_T(m->len)) ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s += m->len ; m++ ;
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goto reswitch ;
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case M_STR + U_OFF + END_ON :
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if ( strcmp(s, m->data.str) ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s += m->len ; m++ ;
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goto reswitch ;
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case M_STR + U_ON + END_OFF :
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if ( !(s = str_str(s, m->data.str, m->len)) ) goto refill ;
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push(m, s+1,ss, U_ON) ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s += m->len ; m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_STR + U_ON + END_ON :
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if ( !str_end ) str_end = s + strlen(s) ;
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ts = str_end - m->len ;
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if (ts < s || memcmp(ts,m->data.str,SIZE_T(m->len+1))) goto refill ;
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if ( !ss )
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if ( cb_ss && ts > cb_ss ) goto refill ;
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else ss = ts ;
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s = str_end ; m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_CLASS + U_OFF + END_OFF :
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if ( !ison(*m->data.bvp, s[0] ) ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s++ ; m++ ;
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goto reswitch ;
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case M_CLASS + U_OFF + END_ON :
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if ( s[1] || !ison(*m->data.bvp,s[0]) ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s++ ; m++ ;
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goto reswitch ;
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case M_CLASS + U_ON + END_OFF :
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while ( !ison(*m->data.bvp,s[0]) )
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if ( s[0] == 0 ) goto refill ;
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else s++ ;
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s++ ;
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push(m, s, ss, U_ON) ;
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if ( !ss )
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if ( cb_ss && s-1 > cb_ss ) goto refill ;
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else ss = s-1 ;
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m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_CLASS + U_ON + END_ON :
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if ( ! str_end ) str_end = s + strlen(s) ;
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if ( ! ison(*m->data.bvp, str_end[-1]) ) goto refill ;
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if ( !ss )
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if ( cb_ss && str_end-1 > cb_ss ) goto refill ;
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else ss = str_end-1 ;
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s = str_end ; m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_ANY + U_OFF + END_OFF :
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if ( s[0] == 0 ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s++ ; m++ ;
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goto reswitch ;
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case M_ANY + U_OFF + END_ON :
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if ( s[0] == 0 || s[1] != 0 ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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s++ ; m++ ;
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goto reswitch ;
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case M_ANY + U_ON + END_OFF :
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if ( s[0] == 0 ) goto refill ;
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s++ ;
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push(m, s, ss, U_ON) ;
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if ( !ss )
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if ( cb_ss && s-1 > cb_ss ) goto refill ;
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else ss = s-1 ;
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m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_ANY + U_ON + END_ON :
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if ( s[0] == 0 ) goto refill ;
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if ( ! str_end ) str_end = s + strlen(s) ;
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if ( !ss )
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if ( cb_ss && str_end-1 > cb_ss ) goto refill ;
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else ss = str_end - 1 ;
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s = str_end ; m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_START + U_OFF + END_OFF :
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case M_START + U_ON + END_OFF :
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if ( s != str ) goto refill ;
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ss = s ;
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m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_START + U_OFF + END_ON :
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case M_START + U_ON + END_ON :
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if ( s != str || s[0] != 0 ) goto refill ;
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ss = s ;
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m++ ; u_flag = U_OFF ;
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goto reswitch ;
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case M_END + U_OFF :
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if ( s[0] != 0 ) goto refill ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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m++ ; goto reswitch ;
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case M_END + U_ON :
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s = str_end ? str_end : (str_end = s + strlen(s)) ;
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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m++ ; u_flag = U_OFF ;
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goto reswitch ;
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CASE_UANY(M_U) :
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if ( !ss )
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if ( cb_ss && s > cb_ss ) goto refill ;
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else ss = s ;
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u_flag = U_ON ; m++ ;
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goto reswitch ;
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CASE_UANY(M_1J) :
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m += m->data.jump ;
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goto reswitch ;
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CASE_UANY(M_2JA) : /* take the non jump branch */
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push(m+m->data.jump, s, ss, u_flag) ;
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m++ ;
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goto reswitch ;
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CASE_UANY(M_2JB) : /* take the jump branch */
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push(m+1, s, ss, u_flag) ;
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m += m->data.jump ;
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goto reswitch ;
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case M_ACCEPT + U_OFF :
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if ( !ss ) ss = s ;
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if ( !cb_ss || ss < cb_ss || ss == cb_ss && s > cb_e )
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{ /* we have a new current best */
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cb_ss = ss ; cb_e = s ;
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}
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goto refill ;
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case M_ACCEPT + U_ON :
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if ( !ss ) ss = s ;
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else
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s = str_end ? str_end : (str_end = s + strlen(s)) ;
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if ( !cb_ss || ss < cb_ss || ss == cb_ss && s > cb_e )
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{ /* we have a new current best */
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cb_ss = ss ; cb_e = s ;
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}
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goto refill ;
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default :
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RE_panic("unexpected case in REmatch") ;
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}
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}
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