DM-16496: add support for XOR #435
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| switch (_logicalOperatorType) { | ||
| case LogicalOperatorCBH::AND: { | ||
| logicalTerm = make_shared<query::AndTerm>(); | ||
| for (auto term : _terms) { |
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auto const& maybe to avoid copy (and below)
| case LogicalOperatorCBH::AND: { | ||
| logicalTerm = make_shared<query::AndTerm>(); | ||
| for (auto term : _terms) { | ||
| if (false == logicalTerm->merge(*term)) { |
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I think there is a special ! operator in C++ for this kind of test (also named not) 😉
| logicalTerm = make_shared<query::OrTerm>(); | ||
| for (auto term : _terms) { | ||
| if (false == logicalTerm->merge(*term)) { | ||
| logicalTerm->addBoolTerm(make_shared<query::AndTerm>(term)); |
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What is the reason you have to wrap it into AndTerm here?
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It has something to do with getting it into disjunctive normal form. @fritzm can explain it to us (me, again) in the meeting tomorrow.
| } else { | ||
| auto term = dynamic_pointer_cast<query::BoolFactor>(otherTerm->copySyntax()); | ||
| ASSERT_EXECUTION_CONDITION(term != nullptr, "XOR currently only works with BoolFactor", _ctx); | ||
| term->setHasNot(true); |
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Does this handle terms that already have NOT, I mean something like:
A XOR NOT B
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hrm. good question! I'll investigate.
| @@ -271,7 +273,9 @@ BoolFactorTerm::Ptr BetweenPredicate::clone() const { | |||
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| void BetweenPredicate::dbgPrint(std::ostream& os) const { | |||
| os << "BetweenPredicate(value:" << value; | |||
| os << ", NOT:" << (hasNot ? "true" : "false"); | |||
| if (hasNot) { | |||
| os << " NOT,"; | |||
| "select ra_PS, objectId from Object where (ra_PS > 1 and not ra_PS < 2) OR (not ra_PS > 1 and ra_PS < 2)", | ||
| [](query::SelectStmt::Ptr const & selectStatement) {}, | ||
| "SELECT ra_PS,objectId FROM Object WHERE (ra_PS>1 AND NOT ra_PS<2) OR (NOT ra_PS>1 AND ra_PS<2)" | ||
| ), |
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With that nontrivial transforms I'd prefer to see more tests with XOR combinations, e.g.
A XOR NOT B
NOT A XOR NOT B
A XOR B XOR C
A XOR B OR C XOR D
A XOR B AND C XOR D
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Last couple of expressions were about operator precedence but I'm not sure that they cover all cases correctly, try to think about more cases. In mysql XOR is between AND and OR in precedence.
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