/**
* Algorithm of Tarjan for computing the strongly connected components of a graph.
*
* @param v current node
* @throws QueryException if a variable directly calls itself
*/
private void tarjan(final int v) throws QueryException {
final int ixv = 2 * v, llv = ixv + 1, idx = next++;
while (list.size() <= llv) list.add(-1);
list.set(ixv, idx);
list.set(llv, idx);
stack.push(v);
for (final int w : adjacentTo(v)) {
final int ixw = 2 * w, llw = ixw + 1;
if (list.size() <= ixw || list.get(ixw) < 0) {
// Successor w has not yet been visited; recurse on it
tarjan(w);
list.set(llv, Math.min(list.get(llv), list.get(llw)));
} else if (stack.contains(w)) {
// Successor w is in stack S and hence in the current SCC
list.set(llv, Math.min(list.get(llv), list.get(ixw)));
}
}
// If v is a root node, pop the stack and generate an SCC
if (list.get(llv) == list.get(ixv)) {
int w;
Scope[] out = null;
do {
w = stack.pop();
final Scope scp = scopes.get(w);
out = out == null ? new Scope[] {scp} : Array.add(out, scp);
} while (w != v);
result.add(out);
}
}
/**
* Finds line and column for the specified query parser.
*
* @param parser parser
*/
void pos(final InputParser parser) {
markedCol = parser.mark;
if (info != null) return;
// check if line/column information has already been added
parser.pos = Math.min(parser.mark, parser.length);
info = new InputInfo(parser);
}
/**
* Adds/subtracts the specified yearMonth duration.
*
* @param dur duration
* @param plus plus/minus flag
* @param ii input info
* @throws QueryException query exception
*/
final void calc(final YMDur dur, final boolean plus, final InputInfo ii) throws QueryException {
final long m = plus ? dur.mon : -dur.mon;
final long mn = mon + m;
mon = (byte) mod(mn, 12);
yea += div(mn, 12);
day = (byte) Math.min(dpm(yea, mon) - 1, day);
if (yea <= MIN_YEAR || yea > MAX_YEAR) throw YEARRANGE_X.get(ii, yea);
}
