public static IList closure(IList rel1) {
Type resultType = rel1.getType().closure(); // will throw exception if not binary and reflexive
IList tmp = rel1;
int prevCount = 0;
ShareableValuesHashSet addedTuples = new ShareableValuesHashSet();
while (prevCount != tmp.length()) {
prevCount = tmp.length();
IList tcomp = compose(tmp, tmp);
IListWriter w = List.createListWriter(resultType.getElementType());
for (IValue t1 : tcomp) {
if (!tmp.contains(t1)) {
if (!addedTuples.contains(t1)) {
addedTuples.add(t1);
w.append(t1);
}
}
}
tmp = tmp.concat(w.done());
addedTuples.clear();
}
return tmp;
}
