ExpressionNode Multiplication::simplify(ExpressionNode& left, ExpressionNode& right) const
{
// unimplemented
ExpressionNode newNode(&MULTIPLICATION);
if (left.getType() == NUMBER && right.getType() == NUMBER)
{
return ExpressionNode(left.getValue() * right.getValue());
}
newNode.appendChild(left);
newNode.appendChild(right);
return newNode;
}
ExpressionNode::ExpressionNode(const ExpressionNode & other): //copy constructor
type(other.getType()), operation(other.getOperation()), activechildren(other.getOperation()->getArity()),
right(0), firstChild(0), variable(other.getVariable()), value(other.getValue())
{
setRight(other.getRight());
setFirstChild(other.getFirstChild()); // automatically also sets other children
}
void ExpressionNode::replace(const ExpressionNode &newNode)
{
std::clog << "...<replacing> " << *this << " with " << newNode << std::endl;
//ExpressionNode *curOld;
//ExpressionNode *curNew;
setType(newNode.getType());
setOperation(newNode.getOperation());
// setRight(newNode.getRight());
setFirstChild(newNode.getFirstChild()); // automatically also sets other children
//curOld = firstChild;
//curNew = newNode.getFirstChild();
//while (curNew != 0)
//{
//curOld->setRight(curNew->getRight());
//curOld = curOld->getRight();
//curNew = curNew->getRight();
//}
setVariable(newNode.getVariable());
setValue(newNode.getValue());
std::clog << "...</replacing>" << std::endl;
}
bool ExpressionNode::operator== (const ExpressionNode& other) const
{
ExpressionNode *selfptr;
ExpressionNode *otherptr;
if (getType() == other.getType() &&
getOperation() == other.getOperation() &&
getVariable() == other.getVariable() &&
getValue() == other.getValue() )
{
selfptr = firstChild;
otherptr = other.getFirstChild();
while (selfptr != 0 && otherptr != 0)
{
if (*selfptr == *otherptr)
{
selfptr = selfptr->getRight();
otherptr = otherptr->getRight();
}
else
{
return false;
}
}
if (selfptr == 0 && otherptr == 0)
{
return true;
}
else
{
assert(selfptr != otherptr);
return false;
}
}
else
{
return false;
}
}
bool Multiplication::isCompatible(const ExpressionNode& left, const ExpressionNode& right)
{
if (left.getType() == NUMBER && right.getType() == NUMBER)
{
return true;
}
else if (left.getType() == VARIABLE && right.getType() == VARIABLE)
{
if (left.getVariable() == right.getVariable())
{
return true;
}
}
else if (left.getType() == OPERATION)
{
if (left.getOperation() == &ADDITION || left.getOperation() == &SUM)
{
return true;
}
else if (left.getOperation() == &MULTIPLICATION || left.getOperation() == &PRODUCT)
{
return true;
}
}
else if (right.getType() == OPERATION)
{
if (right.getOperation() == &ADDITION || right.getOperation() == &SUM)
{
return true;
}
else if (right.getOperation() == &MULTIPLICATION || right.getOperation() == &PRODUCT)
{
return true;
}
}
return false;
}
ExpressionNode Addition::simplify(ExpressionNode& left, ExpressionNode& right) const
{
clog << "checkpoint addsimplify" << endl;
//simplest case: at least one side is just 0
if (left.getType() == NUMBER && left.getValue().getInt() == 0)
{
return right;
}
else if (right.getType() == NUMBER && right.getValue().getInt() == 0)
{
return left;
}
// for each left term: for each right term: try adding
stack <ExpressionNode*> leftNodeStack;
ExpressionNode * currentLeftNode = &left;
bool leftFinished = false;
stack <ExpressionNode*> rightNodeStack;
vector <ExpressionNode*> rightDeleteList;
ExpressionNode * currentRightNode = &right;
bool rightFinished = false;
ExpressionNode newNode(&ADDITION);
while (leftFinished == false)
{
clog << "looping left" << endl;
if (currentLeftNode->getType() == OPERATION && currentLeftNode->getOperation() == &ADDITION)
{
if (currentLeftNode->getFirstChild() == 0)
{
throw ExpressionNode::WrongArityError();
}
currentLeftNode = currentLeftNode->getFirstChild();
leftNodeStack.push(currentLeftNode);
continue;
}
// leaf term on left tree: traverse right tree
rightFinished = false;
currentRightNode = &right;
while (rightFinished == false)
{
clog << "looping right" << endl;
if (currentRightNode->getType() == OPERATION && currentRightNode->getOperation() == &ADDITION)
{
if (currentRightNode->getFirstChild() == 0)
{
throw ExpressionNode::WrongArityError();
}
currentRightNode = currentRightNode->getFirstChild();
rightNodeStack.push(currentRightNode);
continue;
}
assert(currentLeftNode != 0);
assert(currentRightNode !=0);
clog << "checkpoint addsimplify: before isAddable(" << *currentLeftNode << ", " << *currentRightNode << ")"<< endl;
// leaf terms on both sides: attempt adding
if (isCompatible(*currentLeftNode, *currentRightNode))
{
clog << "checkpoint addsimplify: after isAddable; " << endl;
clog << *currentLeftNode << " " << *currentRightNode << endl;
(*currentLeftNode) = addTerms(*currentLeftNode, *currentRightNode);
clog << "checkpoint addsimplify: after addTerms; " << endl;
clog << "currentLeftNode: " << *currentLeftNode << " RightNode:" << *currentRightNode << endl;
clog << "left " << left << "right " << right << endl;
if (currentRightNode == &right)
{
//entire right tree has been assimilated
return left;
}
// try marking for deletion after right loop instead of removing
rightDeleteList.push_back(currentRightNode);
}
while (true)
{
clog << "rightNodeStack: " << rightNodeStack.size() << endl;
if (rightNodeStack.size() != 0) clog << "rightNodeStack.top(): " << *(rightNodeStack.top()) << endl;
if (rightNodeStack.size() == 0)
{
rightFinished = true;
break;
}
currentRightNode = rightNodeStack.top();
rightNodeStack.pop();
if (currentRightNode->getRight() != 0)
{
currentRightNode = currentRightNode->getRight();
rightNodeStack.push(currentRightNode);
break;
}
}
}
// deleting marked rights
for (vector<ExpressionNode*>::iterator it = rightDeleteList.begin(); it != rightDeleteList.end(); it++)
{
right.remove(*it);
}
rightDeleteList.clear();
clog << "here left: " << left << "right: " << right <<endl;
//clog << "leftNodeStack: " << leftNodeStack.size() << endl;
//if (leftNodeStack.size() > 0)
//{
//clog << "leftNodeStack: " << *(leftNodeStack.top()) << endl;
//}
while (true)
{
if (leftNodeStack.size() == 0)
{
leftFinished = true;
break;
}
currentLeftNode = leftNodeStack.top();
leftNodeStack.pop();
if (currentLeftNode->getRight() != 0)
{
currentLeftNode = currentLeftNode->getRight();
leftNodeStack.push(currentLeftNode);
break;
}
}
}
//still some terms left on right
newNode.appendChild(left);
newNode.appendChild(right);
return newNode;
}
ExpressionNode Addition::addTerms(const ExpressionNode& term1, const ExpressionNode& term2) const
{
clog << "checkpoint addTerms" << endl;
Number coefficient1;
Number coefficient2;
const ExpressionNode * varpart1;
const ExpressionNode * varpart2;
ExpressionNode * left;
ExpressionNode * right;
ExpressionNode newRight;
ExpressionNode newCoef;
ExpressionNode newNode;
if (term1.getType() == NUMBER)
{
coefficient1 = term1.getValue();
varpart1 = 0;
}
else if (term1.getType() == OPERATION)
{
if (term1.getOperation() == &MULTIPLICATION)
{
left = term1.getFirstChild();
right = left->getRight();
if (left->getType() == NUMBER)
{
coefficient1 = left->getValue();
varpart1 = right;
}
else if (right->getType() == NUMBER)
{
coefficient1 = right->getValue();
varpart1 = left;
}
else
{
coefficient1 = MULTIPLICATION.getIdentity();
varpart1 = &term1;
}
}
else
{
coefficient1 = MULTIPLICATION.getIdentity();
varpart1 = &term1;
}
}
else // VARIABLE
{
assert(term1.getType() == VARIABLE);
coefficient1 = MULTIPLICATION.getIdentity();
varpart1 = &term1;
}
if (term2.getType() == NUMBER)
{
coefficient2 = term2.getValue();
varpart2 = 0;
}
else if (term2.getType() == OPERATION)
{
if (term2.getOperation() == &MULTIPLICATION)
{
left = term2.getFirstChild();
right = left->getRight();
if (left->getType() == NUMBER)
{
coefficient2 = left->getValue();
varpart2 = right;
}
else if (right->getType() == NUMBER)
{
coefficient2 = right->getValue();
varpart2 = left;
}
else
{
coefficient2 = MULTIPLICATION.getIdentity();
varpart2 = &term2;
}
}
else
{
coefficient2 = MULTIPLICATION.getIdentity();
varpart2 = &term2;
}
}
else // VARIABLE
{
assert(term2.getType() == VARIABLE);
coefficient2 = MULTIPLICATION.getIdentity();
varpart2 = &term2;
}
if (varpart1 != 0 && varpart2 != 0)
{
if (*varpart1 == *varpart2)
{
clog << "addTerms simplify like terms" << endl
<< "coef1: " << coefficient1 << " var1: " << *varpart1 << endl
<< "coef2: " << coefficient2 << " var2: " << *varpart2 << endl;
newCoef = ExpressionNode(coefficient1 + coefficient2);
newRight = *varpart1;
newNode = ExpressionNode(&MULTIPLICATION);
newNode.appendChild(newCoef);
newNode.appendChild(newRight);
clog << "sum: " << newNode << endl;
return newNode;
}
else
{
clog << "*varpart1: " << *varpart1 << " *varpart2: " << endl;
throw ExpressionNode::GenericError("adding unaddable terms");
}
}
else
{
if (varpart1 == 0 && varpart2 == 0)
{
clog << "sum: " << coefficient1 + coefficient2 << endl;
return ExpressionNode(coefficient1 + coefficient2);
}
else
{
throw ExpressionNode::GenericError("adding unaddable terms");
}
}
throw ExpressionNode::GenericError("reached end of addTerms w/o returning.");
//if (left.getNodeType() == NUMBER && right.getNodeType() == NUMBER)
//{
//ExpressionNode newNode;
//newNode.setNodeType(NUMBER);
//newNode.setValue(Number(left.getValue().getInt() + right.getValue().getInt()));
//return newNode;
//}
}
bool Addition::isCompatible(const ExpressionNode& term1, const ExpressionNode& term2) const
{
clog << "checkpoint isAddable(" << term1 << ", " << term2 << ")" << endl;
const ExpressionNode * varpart1(0);
const ExpressionNode * varpart2(0);
const ExpressionNode * left;
const ExpressionNode * right;
if (term1.getType() == NUMBER)
{
varpart1 = 0;
}
else if (term1.getType() == OPERATION)
{
if (term1.getOperation() == &MULTIPLICATION)
{
left = term1.getFirstChild();
right = left->getRight();
if (left->getType() == NUMBER)
{
varpart1 = right;
}
else if (right->getType() == NUMBER)
{
varpart1 = left;
}
else
{
varpart1 = &term1;
}
}
else
{
varpart1 = &term1;
}
}
else // VARIABLE
{
assert(term1.getType() == VARIABLE);
varpart1 = &term1;
}
if (term2.getType() == NUMBER)
{
varpart2 = 0;
}
else if (term2.getType() == OPERATION)
{
if (term2.getOperation() == &MULTIPLICATION)
{
left = term2.getFirstChild();
right = left->getRight();
if (left->getType() == NUMBER)
{
varpart2 = right;
}
else if (right->getType() == NUMBER)
{
varpart2 = left;
}
else
{
varpart2 = &term2;
}
}
else
{
varpart2 = &term2;
}
}
else // VARIABLE
{
assert(term2.getType() == VARIABLE);
varpart2 = &term2;
}
if (varpart1 != 0 && varpart2 != 0)
{
if (*varpart1 == *varpart2)
{
return true;
}
else
{
return false;
}
}
else
{
if (varpart1 == 0 && varpart2 == 0)
{
// both numbers
return true;
}
else
{
return false;
}
}
}
ExpressionNode Addition::simplify(ExpressionNode& left, ExpressionNode& right)
{
std::clog << "checkpoint addsimplify" << std::endl;
//simplest case: at least one side is just 0
if (left.getType() == NUMBER && left.getValue().getInt() == 0)
{
return right;
}
else if (right.getType() == NUMBER && right.getValue().getInt() == 0)
{
return left;
}
// for each left term: for each right term: try adding
std::stack <ExpressionNode*> leftNodeStack;
ExpressionNode * currentLeftNode = &left;
bool leftFinished = false;
std::stack <ExpressionNode*> rightNodeStack;
ExpressionNode * currentRightNode = &right;
bool rightFinished = false;
ExpressionNode * tempNodePtr;
ExpressionNode newNode;
while (leftFinished == false)
{
std::clog << "looping left" << std::endl;
if (currentLeftNode->getType() == OPERATION && currentLeftNode->getOperation() == &ADDITION)
{
if (currentLeftNode->getFirstChild() == 0)
{
throw ExpressionNode::WrongArityError();
}
currentLeftNode = currentLeftNode->getFirstChild();
leftNodeStack.push(currentLeftNode);
continue;
}
// leaf term on left tree: traverse right tree
while (rightFinished == false)
{
std::clog << "looping right" << std::endl;
if (currentRightNode->getType() == OPERATION && currentRightNode->getOperation() == &ADDITION)
{
if (currentRightNode->getFirstChild() == 0)
{
throw ExpressionNode::WrongArityError();
}
currentRightNode = currentRightNode->getFirstChild();
rightNodeStack.push(currentRightNode);
continue;
}
std::clog << "checkpoint addsimplify: before isAddable; " << std::endl;
// leaf terms on both sides: attempt adding
if (isAddable(*currentLeftNode, *currentRightNode))
{
std::clog << "checkpoint addsimplify: after isAddable; " << std::endl;
std::clog << *currentLeftNode << " " << *currentRightNode << std::endl;
std::clog << "add testrun: " << addTerms(*currentLeftNode, *currentRightNode);
(*currentLeftNode).replace( addTerms(*currentLeftNode, *currentRightNode) );
std::clog << "checkpoint addsimplify: after addTerms; " << std::endl;
if (currentRightNode == &right)
{
//entire right tree has been assimilated
return left;
}
tempNodePtr = currentRightNode;
currentRightNode = right.findParentOf(*currentRightNode);
right.remove(*tempNodePtr);
}
while (true)
{
if (rightNodeStack.size() == 0)
{
rightFinished = true;
break;
}
currentRightNode = rightNodeStack.top();
rightNodeStack.pop();
if (currentRightNode->getRight() != 0)
{
currentRightNode = currentRightNode->getRight();
rightNodeStack.push(currentRightNode);
break;
}
}
}
while (true)
{
if (leftNodeStack.size() == 0)
{
leftFinished = true;
break;
}
currentLeftNode = leftNodeStack.top();
leftNodeStack.pop();
if (currentLeftNode->getRight() != 0)
{
currentLeftNode = currentLeftNode->getRight();
leftNodeStack.push(currentLeftNode);
break;
}
}
}
//still some terms left on right
left.setRight(&right);
newNode.init(&ADDITION, &left);
return newNode;
}