Method executeOr

src/dsql/BoolNodes.cpp:234–278

}

bool BinaryBoolNode::executeOr(thread_db* tdbb, Request* request) const
{
	// If either operand is true, then the result is true;
	// If both are false, the result is false;
	// Otherwise, the result is NULL.
	//
	// op 1            op 2            result
	// ----            ----            ------
	// F               F                F
	// F               T                T
	// F               N                N
	// T               F                T
	// T               T                T
	// T               N                T
	// N               F                N
	// N               T                T
	// N               N                N

	const bool value1 = arg1->execute(tdbb, request);

	const ULONG flags = request->req_flags;
	request->req_flags &= ~req_null;

	if (value1)
	{
		// First term is true, why the whole expression is true.
		// NULL flag is already turned off a few lines above.
		return true;
	}

	const bool value2 = arg2->execute(tdbb, request);

	if (value1 || value2)
	{
		request->req_flags &= ~req_null;
		return true;
	}

	// restore saved NULL state

	if (flags & req_null)
		request->req_flags |= req_null;

	return false;
}


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