/*
- p_ere - ERE parser top level, concatenation and alternation
== static void p_ere(struct parse *p, int stop, size_t reclimit);
*/
static void
p_ere(
struct parse *p,
int stop, /* character this ERE should end at */
size_t reclimit)
{
char c;
sopno prevback = 0; /* pacify gcc */
sopno prevfwd = 0; /* pacify gcc */
sopno conc;
int first = 1; /* is this the first alternative? */
_DIAGASSERT(p != NULL);
if (reclimit++ > RECLIMIT || p->error == REG_ESPACE) {
p->error = REG_ESPACE;
return;
}
for (;;) {
/* do a bunch of concatenated expressions */
conc = HERE();
while (MORE() && (c = PEEK()) != '|' && c != stop)
p_ere_exp(p, reclimit);
REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */
if (!EAT('|'))
break; /* NOTE BREAK OUT */
if (first) {
INSERT(OCH_, conc); /* offset is wrong */
prevfwd = conc;
prevback = conc;
first = 0;
}
ASTERN(OOR1, prevback);
prevback = THERE();
AHEAD(prevfwd); /* fix previous offset */
prevfwd = HERE();
EMIT(OOR2, 0); /* offset is very wrong */
}
if (!first) { /* tail-end fixups */
AHEAD(prevfwd);
ASTERN(O_CH, prevback);
}
assert(!MORE() || SEE(stop));
}
/*
- p_ere - ERE parser top level, concatenation and alternation
*/
static void
p_ere(struct parse *p, int stop) /* character this ERE should end at */
{
char c;
sopno prevback;
sopno prevfwd;
sopno conc;
int first = 1; /* is this the first alternative? */
for (;;) {
/* do a bunch of concatenated expressions */
conc = HERE();
while (MORE() && (c = PEEK()) != '|' && c != stop)
p_ere_exp(p);
REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */
if (!EAT('|'))
break; /* NOTE BREAK OUT */
if (first) {
INSERT(OCH_, conc); /* offset is wrong */
prevfwd = conc;
prevback = conc;
first = 0;
}
ASTERN(OOR1, prevback);
prevback = THERE();
AHEAD(prevfwd); /* fix previous offset */
prevfwd = HERE();
EMIT(OOR2, 0); /* offset is very wrong */
}
if (!first) { /* tail-end fixups */
AHEAD(prevfwd);
ASTERN(O_CH, prevback);
}
assert(!MORE() || SEE(stop));
}
