void test_depth_first_iterator::test_dfi()
{
  std::string infix("7-(3+(4-6))+1*8");
  CEvaluationTree* pTree = new CEvaluationTree();
  pTree->setInfix(infix);
  std::string s = pTree->getInfix();
  CPPUNIT_ASSERT(pTree->getRoot() != NULL);
  CEvaluationNodeDepthFirstIterator it(pTree->getRoot());
  CPPUNIT_ASSERT(it.isValid());
  CEvaluationNode* pNode = NULL;
  CEvaluationNodeNumber* pNumberNode = NULL;
  CEvaluationNodeOperator* pOperatorNode = NULL;
  // 7
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::NUMBER);
  pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(pNode);
  CPPUNIT_ASSERT(pNumberNode != NULL);
  CPPUNIT_ASSERT((fabs(pNumberNode->getValue() - 7) / 7.0) <= std::numeric_limits<double>::min());
  // 3
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::NUMBER);
  pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(pNode);
  CPPUNIT_ASSERT(pNumberNode != NULL);
  CPPUNIT_ASSERT((fabs(pNumberNode->getValue() - 3) / 3.0) <= std::numeric_limits<double>::min());
  // 4
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::NUMBER);
  pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(pNode);
  CPPUNIT_ASSERT(pNumberNode != NULL);
  CPPUNIT_ASSERT((fabs(pNumberNode->getValue() - 4) / 4.0) <= std::numeric_limits<double>::min());
  // 6
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::NUMBER);
  pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(pNode);
  CPPUNIT_ASSERT(pNumberNode != NULL);
  CPPUNIT_ASSERT((fabs(pNumberNode->getValue() - 6) / 6.0) <= std::numeric_limits<double>::min());
  // -
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::OPERATOR);
  pOperatorNode = dynamic_cast<CEvaluationNodeOperator*>(pNode);
  CPPUNIT_ASSERT(pOperatorNode != NULL);
  CPPUNIT_ASSERT((CEvaluationNodeOperator::SubType)CEvaluationNode::subType(pOperatorNode->getType()) == CEvaluationNodeOperator::MINUS);
  // +
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::OPERATOR);
  pOperatorNode = dynamic_cast<CEvaluationNodeOperator*>(pNode);
  CPPUNIT_ASSERT(pOperatorNode != NULL);
  CPPUNIT_ASSERT((CEvaluationNodeOperator::SubType)CEvaluationNode::subType(pOperatorNode->getType()) == CEvaluationNodeOperator::PLUS);
  // -
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::OPERATOR);
  pOperatorNode = dynamic_cast<CEvaluationNodeOperator*>(pNode);
  CPPUNIT_ASSERT(pOperatorNode != NULL);
  CPPUNIT_ASSERT((CEvaluationNodeOperator::SubType)CEvaluationNode::subType(pOperatorNode->getType()) == CEvaluationNodeOperator::MINUS);
  // 1
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::NUMBER);
  pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(pNode);
  CPPUNIT_ASSERT(pNumberNode != NULL);
  CPPUNIT_ASSERT((fabs(pNumberNode->getValue() - 1) / 1.0) <= std::numeric_limits<double>::min());
  // 8
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::NUMBER);
  pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(pNode);
  CPPUNIT_ASSERT(pNumberNode != NULL);
  CPPUNIT_ASSERT((fabs(pNumberNode->getValue() - 8) / 8.0) <= std::numeric_limits<double>::min());
  // *
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::OPERATOR);
  pOperatorNode = dynamic_cast<CEvaluationNodeOperator*>(pNode);
  CPPUNIT_ASSERT(pOperatorNode != NULL);
  CPPUNIT_ASSERT((CEvaluationNodeOperator::SubType)CEvaluationNode::subType(pOperatorNode->getType()) == CEvaluationNodeOperator::MULTIPLY);
  // +
  ++it;
  CPPUNIT_ASSERT(it.isValid() == true);
  pNode = *it;
  CPPUNIT_ASSERT(pNode != NULL);
  CPPUNIT_ASSERT(CEvaluationNode::type(pNode->getType()) == CEvaluationNode::OPERATOR);
  pOperatorNode = dynamic_cast<CEvaluationNodeOperator*>(pNode);
  CPPUNIT_ASSERT(pOperatorNode != NULL);
  CPPUNIT_ASSERT((CEvaluationNodeOperator::SubType)CEvaluationNode::subType(pOperatorNode->getType()) == CEvaluationNodeOperator::PLUS);

  ++it;
  CPPUNIT_ASSERT(it.isValid() == false);
  CPPUNIT_ASSERT(*it == NULL);

  delete pTree;
}
bool CEvaluationNodeNormalizer::eliminateMultipleNumbers(CEvaluationNodeOperator::SubType subType, std::vector<CEvaluationNode*>& chainNodes)
{
  // check if there are several numerical values in the operator chain and
  // evaluate those operations
  bool changed = false;

  if (chainNodes.size() > 1)
    {
      std::vector<CEvaluationNode*>::iterator it = chainNodes.begin(), endit = chainNodes.end();

      if (subType == CEvaluationNodeOperator::MULTIPLY || subType == CEvaluationNodeOperator::PLUS)
        {

          double value = (subType == CEvaluationNodeOperator::MULTIPLY) ? 1.0 : 0.0;
          CEvaluationNodeNumber* pNumberNode = NULL;
          std::vector<CEvaluationNode*> numbers;

          while (it != endit)
            {
              pNumberNode = dynamic_cast<CEvaluationNodeNumber*>(*it);

              if (pNumberNode != NULL)
                {
                  numbers.push_back(pNumberNode);

                  if (subType == CEvaluationNodeOperator::MULTIPLY)
                    {
                      value *= pNumberNode->value();
                    }
                  else
                    {
                      value += pNumberNode->value();
                    }
                }

              ++it;
            }

          if (numbers.size() > 1)
            {
              changed = true;
              it = numbers.begin(), endit = numbers.end();
              // don't delete the last one since we reset it's value
              --endit;

              while (it != endit)
                {
                  chainNodes.erase(std::find(chainNodes.begin(), chainNodes.end(), *it));
                  delete *it;
                  ++it;
                }

              std::ostringstream os;
              os << value;
              (*it)->setData(os.str());
            }
        }
    }

  return changed;
}