void Database::processRule(Rule* rule) {
//Find the relation in the list of schemes matching the head of the predicate
Relation* headRelation = getHeadRelation(rule);
//Get the list of predicates
std::vector<Predicate*> predicateList = rule->j;
//Create new relations from each predicate
std::vector<Relation*> relationList = getRelationList(predicateList);
//Natural join the relations from the predicates
Relation* newRelation = join(relationList);
//Project on the final relation; only keep columns matching variables in the rule head
std::vector<std::string> headVariables = getHeadVariables(rule->hpl);
newRelation = newRelation->project(headVariables);
//Find the relation in the database that matches the head of the rule
//Already done (it's headRelation)
//Rename attributes in the new relation so it matches the rule head's schema
newRelation = renameToMatch(headRelation, newRelation, headVariables);
//Union the new relation with the matching relation
headRelation = unionWith(headRelation, newRelation);
std::sort(headRelation->facts.begin(), headRelation->facts.end(), Relation::tupleCompare);
}
void PlatformTimeRanges::intersectWith(const PlatformTimeRanges& other)
{
PlatformTimeRanges invertedOther(other);
invertedOther.invert();
invert();
unionWith(invertedOther);
invert();
}
