void patch(int l, int val) {
while (l != 0) {
Inst i = inst.get(l >> 1);
if ((l & 1) == 0) {
l = i.out;
i.out = val;
} else {
l = i.arg;
i.arg = val;
}
}
}
// prefix() returns a pair of a literal string that all matches for the
// regexp must start with, and a boolean which is true if the prefix is the
// entire match. The string is returned by appending to |prefix|.
boolean prefix(StringBuilder prefix) {
Inst i = skipNop(start);
// Avoid allocation of buffer if prefix is empty.
if (i.op() != Inst.Op.RUNE || i.runes.length != 1) {
return i.op == Inst.Op.MATCH; // (append "" to prefix)
}
// Have prefix; gather characters.
while (i.op() == Inst.Op.RUNE && i.runes.length == 1 && (i.arg & RE2.FOLD_CASE) == 0) {
prefix.appendCodePoint(i.runes[0]); // an int, not a byte.
i = skipNop(i.out);
}
return i.op == Inst.Op.MATCH;
}
int append(int l1, int l2) {
if (l1 == 0) {
return l2;
}
if (l2 == 0) {
return l1;
}
int last = l1;
for (; ; ) {
int next = next(last);
if (next == 0) {
break;
}
last = next;
}
Inst i = inst.get(last >> 1);
if ((last & 1) == 0) {
i.out = l2;
} else {
i.arg = l2;
}
return l1;
}
