static int piece(void) {
int p;
p=atom();
if(sym==SYM_CHR) {
switch(val) {
case '{': getsym(); p=quantifier(p); chk_get('}',RX_ER_NOLCU); break;
case '?': getsym(); p=choice(empty,p); break;
case '*': getsym(); p=choice(empty,one_or_more(p)); break;
case '+': getsym(); p=one_or_more(p); break;
default: break;
}
}
return p;
}
static int quantifier(int p0) {
int p=empty,n,n0;
n=n0=number();
while(n--) p=group(p,p0);
if(sym==SYM_CHR) {
if(val==',') {
getsym();
if(sym==SYM_CHR && val=='}') {
p=group(p,choice(empty,one_or_more(p0)));
} else {
n=number()-n0; if(n<0) {error(RX_ER_DNUOB); n=0;}
while(n--) p=group(p,choice(empty,p0));
}
}
} else error(RX_ER_NODGT);
return p;
}
str_iter one_or_more(str_iter iter, str_ptr str)
{
return one_or_more(iter, match, str);
}