Initial revision
diff --git a/src/libregexp/rregexec.c b/src/libregexp/rregexec.c
new file mode 100644
index 0000000..e96c972
--- /dev/null
+++ b/src/libregexp/rregexec.c
@@ -0,0 +1,213 @@
+#include "lib9.h"
+#include "regexp9.h"
+#include "regcomp.h"
+
+/*
+ * return 0 if no match
+ * >0 if a match
+ * <0 if we ran out of _relist space
+ */
+static int
+rregexec1(Reprog *progp, /* program to run */
+ Rune *bol, /* string to run machine on */
+ Resub *mp, /* subexpression elements */
+ int ms, /* number of elements at mp */
+ Reljunk *j)
+{
+ int flag=0;
+ Reinst *inst;
+ Relist *tlp;
+ Rune *s;
+ int i, checkstart;
+ Rune r, *rp, *ep;
+ Relist* tl; /* This list, next list */
+ Relist* nl;
+ Relist* tle; /* ends of this and next list */
+ Relist* nle;
+ int match;
+
+ match = 0;
+ checkstart = j->startchar;
+ if(mp)
+ for(i=0; i<ms; i++) {
+ mp[i].s.rsp = 0;
+ mp[i].e.rep = 0;
+ }
+ j->relist[0][0].inst = 0;
+ j->relist[1][0].inst = 0;
+
+ /* Execute machine once for each character, including terminal NUL */
+ s = j->rstarts;
+ do{
+
+ /* fast check for first char */
+ if(checkstart) {
+ switch(j->starttype) {
+ case RUNE:
+ while(*s != j->startchar) {
+ if(*s == 0)
+ return match;
+ s++;
+ }
+ break;
+ case BOL:
+ if(s == bol)
+ break;
+ while(*s != '\n') {
+ if(*s == 0)
+ return match;
+ s++;
+ }
+ break;
+ }
+ }
+
+ r = *s;
+
+ /* switch run lists */
+ tl = j->relist[flag];
+ tle = j->reliste[flag];
+ nl = j->relist[flag^=1];
+ nle = j->reliste[flag];
+ nl->inst = 0;
+
+ /* Add first instruction to current list */
+ _rrenewemptythread(tl, progp->startinst, s);
+
+ /* Execute machine until current list is empty */
+ for(tlp=tl; tlp->inst; tlp++){
+ for(inst=tlp->inst; ; inst = inst->u2.next){
+ switch(inst->type){
+ case RUNE: /* regular character */
+ if(inst->u1.r == r)
+ if(_renewthread(nl, inst->u2.next, &tlp->se)==nle)
+ return -1;
+ break;
+ case LBRA:
+ tlp->se.m[inst->u1.subid].s.rsp = s;
+ continue;
+ case RBRA:
+ tlp->se.m[inst->u1.subid].e.rep = s;
+ continue;
+ case ANY:
+ if(r != '\n')
+ if(_renewthread(nl, inst->u2.next, &tlp->se)==nle)
+ return -1;
+ break;
+ case ANYNL:
+ if(_renewthread(nl, inst->u2.next, &tlp->se)==nle)
+ return -1;
+ break;
+ case BOL:
+ if(s == bol || *(s-1) == '\n')
+ continue;
+ break;
+ case EOL:
+ if(s == j->reol || r == 0 || r == '\n')
+ continue;
+ break;
+ case CCLASS:
+ ep = inst->u1.cp->end;
+ for(rp = inst->u1.cp->spans; rp < ep; rp += 2)
+ if(r >= rp[0] && r <= rp[1]){
+ if(_renewthread(nl, inst->u2.next, &tlp->se)==nle)
+ return -1;
+ break;
+ }
+ break;
+ case NCCLASS:
+ ep = inst->u1.cp->end;
+ for(rp = inst->u1.cp->spans; rp < ep; rp += 2)
+ if(r >= rp[0] && r <= rp[1])
+ break;
+ if(rp == ep)
+ if(_renewthread(nl, inst->u2.next, &tlp->se)==nle)
+ return -1;
+ break;
+ case OR:
+ /* evaluate right choice later */
+ if(_renewthread(tlp, inst->u1.right, &tlp->se) == tle)
+ return -1;
+ /* efficiency: advance and re-evaluate */
+ continue;
+ case END: /* Match! */
+ match = 1;
+ tlp->se.m[0].e.rep = s;
+ if(mp != 0)
+ _renewmatch(mp, ms, &tlp->se);
+ break;
+ }
+ break;
+ }
+ }
+ if(s == j->reol)
+ break;
+ checkstart = j->startchar && nl->inst==0;
+ s++;
+ }while(r);
+ return match;
+}
+
+static int
+rregexec2(Reprog *progp, /* program to run */
+ Rune *bol, /* string to run machine on */
+ Resub *mp, /* subexpression elements */
+ int ms, /* number of elements at mp */
+ Reljunk *j
+)
+{
+ Relist relist0[5*LISTSIZE], relist1[5*LISTSIZE];
+
+ /* mark space */
+ j->relist[0] = relist0;
+ j->relist[1] = relist1;
+ j->reliste[0] = relist0 + nelem(relist0) - 2;
+ j->reliste[1] = relist1 + nelem(relist1) - 2;
+
+ return rregexec1(progp, bol, mp, ms, j);
+}
+
+extern int
+rregexec(Reprog *progp, /* program to run */
+ Rune *bol, /* string to run machine on */
+ Resub *mp, /* subexpression elements */
+ int ms) /* number of elements at mp */
+{
+ Reljunk j;
+ Relist relist0[LISTSIZE], relist1[LISTSIZE];
+ int rv;
+
+ /*
+ * use user-specified starting/ending location if specified
+ */
+ j.rstarts = bol;
+ j.reol = 0;
+ if(mp && ms>0){
+ if(mp->s.sp)
+ j.rstarts = mp->s.rsp;
+ if(mp->e.ep)
+ j.reol = mp->e.rep;
+ }
+ j.starttype = 0;
+ j.startchar = 0;
+ if(progp->startinst->type == RUNE && progp->startinst->u1.r < (Rune)Runeself) {
+ j.starttype = RUNE;
+ j.startchar = progp->startinst->u1.r;
+ }
+ if(progp->startinst->type == BOL)
+ j.starttype = BOL;
+
+ /* mark space */
+ j.relist[0] = relist0;
+ j.relist[1] = relist1;
+ j.reliste[0] = relist0 + nelem(relist0) - 2;
+ j.reliste[1] = relist1 + nelem(relist1) - 2;
+
+ rv = rregexec1(progp, bol, mp, ms, &j);
+ if(rv >= 0)
+ return rv;
+ rv = rregexec2(progp, bol, mp, ms, &j);
+ if(rv >= 0)
+ return rv;
+ return -1;
+}
