C++ BTreeNode::setValue方法代码示例

void Expression::compileConditional( const QString & expression, Code * ifCode, Code * elseCode )
{
	if( expression.contains(QRegExp("=>|=<|=!")) )
	{
		mistake( Microbe::InvalidComparison, expression );
		return;
	}
	if( expression.contains(QRegExp("[^=><!][=][^=]")))
	{
		mistake( Microbe::InvalidEquals );
		return;
	}
	// Make a tree to put the expression in.
	BTreeBase *tree = new BTreeBase();
	BTreeNode *root = new BTreeNode();

	// parse the expression into the tree
	buildTree(expression,tree,root,0);
	
	// Modify the tree so it is always at the top level of the form (kwoerpkwoep) == (qwopekqpowekp)
	if ( root->childOp() != equals &&
			root->childOp() != notequals &&
			root->childOp() != gt &&
			root->childOp() != lt &&
			root->childOp() != ge &&
			root->childOp() != le &&
			root->childOp() != pin &&
			root->childOp() != notpin &&
			root->childOp() != read_keypad )
	{
		BTreeNode *newRoot = new BTreeNode();
		
		BTreeNode *oneNode = new BTreeNode();
		oneNode->setChildOp(noop);
		oneNode->setType(number);
		oneNode->setValue("1");
		
		newRoot->setLeft(root);
		newRoot->setRight(oneNode);
		newRoot->setType(unset);
		newRoot->setChildOp(ge);
		
		tree->setRoot(newRoot);
		root = newRoot;
	}
	// compile the tree into assembly code
	tree->setRoot(root);
	tree->pruneTree(tree->root(),true);
	
	// We might have just a constant expression, in which case we can just always do if or else depending
	// on whether it is true or false.
	if( root->childOp() == noop )
	{
		if( root->value().toInt() == 0 )
			m_pic->mergeCode( elseCode );
		else
			m_pic->mergeCode( ifCode );
		return;
	}
	
	// traverse tree with argument conditionalRoot true
	// so that 3 == x gets integrated with code for if, repeat until etc...
	m_ifCode = ifCode;
	m_elseCode = elseCode;
	traverseTree(tree->root(),true);
	
	// Note deleting the tree deletes all nodes, so the root
	// doesn't need deleting separately.
	delete tree;
}

void BTreeBase::pruneTree(BTreeNode *root, bool /*conditionalRoot*/)
{
	Traverser t(root);
	
	t.descendLeftwardToTerminal();
	bool done = false;
	while(!done)
	{
	//t.descendLeftwardToTerminal();
	if( t.current()->parent() )
	{
		if( t.oppositeNode()->hasChildren() ) pruneTree(t.oppositeNode());
	}
	
	t.moveToParent();
	if( !t.current()->hasChildren() )
	{
		//if(t.current() == t.root()) done = true;
		if(!t.current()->parent()) done = true;
		continue;
	}

	BTreeNode *l = t.current()->left();
	BTreeNode *r = t.current()->right();
	BTreeNode *n = 0;
	BTreeNode *z = 0;
	

	// Deal with situations where there are two constants so we want
	// to evaluate at compile time
	if( (l->type() == number && r->type() == number) ) // && !(t.current()==root&&conditionalRoot) )
	{
		if(t.current()->childOp() == Expression::division && r->value() == "0" ) 
		{
			t.current()->setChildOp(Expression::divbyzero);
			return;
		}
		QString value = QString::number(Parser::doArithmetic(l->value().toInt(),r->value().toInt(),t.current()->childOp()));
		t.current()->deleteChildren();
		t.current()->setChildOp(Expression::noop);
		t.current()->setType(number);
		t.current()->setValue(value);
	}
	
	// Addition and subtraction
	else if(t.current()->childOp() == Expression::addition || t.current()->childOp() == Expression::subtraction)
	{
	// See if one of the nodes is 0, and set n to the node that actually has data,
	// z to the one containing zero.
	bool zero = false;
	if( l->value() == "0" )
	{
		zero = true;
		n = r;
		z = l;
	}
	else if( r->value() == "0" )
	{
		zero = true;
		n = l;
		z = r;
	}
	// Now get rid of the useless nodes
	if(zero)
	{
		BTreeNode *p = t.current(); // save in order to delete after

		replaceNode(p,n);
		t.setCurrent(n);
		// Delete the old nodes
		delete p;
		delete z;
	}
	}
	
	// Multiplication and division
	else if(t.current()->childOp() == Expression::multiplication || t.current()->childOp() == Expression::division)
	{
	// See if one of the nodes is 0, and set n to the node that actually has data,
	// z to the one containing zero.
	bool zero = false;
	bool one = false;
	if( l->value() == "1" )
	{
		one = true;
		n = r;
		z = l;
	}
	else if( r->value() == "1" )
	{
		one = true;
		n = l;
		z = r;
	}
	if( l->value() == "0" )
	{
		zero = true;
		n = r;
		z = l;
	}
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		// ^
		case 4:
		{
		int exppos = findSkipBrackets(expression, '^');
		if( exppos != -1 )
		{
			op = exponent;
			firstEnd = exppos;
			secondStart = exppos + 1;
		}
		else op = noop;
		break;
		}
		
		// AND, OR, XOR
		case 5:
		{
		int bwAndPos = findSkipBrackets(expression, " AND ");
		int bwOrPos = findSkipBrackets(expression, " OR ");
		int bwXorPos = findSkipBrackets(expression, " XOR ");
		if( bwAndPos != -1 )
		{
			op = bwand;
			firstEnd = bwAndPos;
			secondStart = bwAndPos + 5;
		}
		else if( bwOrPos != -1 )
		{
			op = bwor;
			firstEnd = bwOrPos;
			secondStart = bwOrPos + 4;
		}
		else if( bwXorPos != -1 )
		{
			op = bwxor;
			firstEnd = bwXorPos;
			secondStart = bwXorPos + 5;
		}
		else op = noop;
		break;
		}
		
		// NOT
		case 6:
		{
		int bwNotPos = findSkipBrackets(expression, " NOT ");
		if( bwNotPos != -1 )
		{
			op = bwnot;
			unary = true;
			firstEnd = bwNotPos; // this line is not needed for unary things/
			secondStart = bwNotPos + 5;
		}
		else op = noop;
		break;
		}
	}
	
	node->setChildOp(op);
	
	QString tokens[2];
	tokens[0] = expression.left(firstEnd).trimmed();
	tokens[1] = expression.mid(secondStart).trimmed();
	
	if( op != noop )
	{	
		for( int j = 0; j < 2; j++ )
		{
			
			BTreeNode *newNode = new BTreeNode();
			tree->addNode( node, newNode, (j == 0) );
			// we need to strip any brackets from the sub-expression
			
			// try each token again at the same level, if they 
			// don't have any of this level's operators, then the function
			// will go to the next level as below.
			
			// For unary opertaions, e.g NOT, we have no special 
			// code for nodes with only one child, so we leave the left
			// hand child blank and put the rest in the right hand node.
			if( unary && j == 0 )
			{
				newNode->setValue("");
				newNode->setType(number);
			}
			else buildTree(tokens[j], tree, newNode, 0 );
		}
	}
	else
	{
		// if there was no relevant operation i.e. " 3*4 / 6" as opposed to " 3*4 + 6"
		// then just pass the node onto the next parsing level.
		// unless we are at the lowest level, in which case we have reached a final value.
		if( level == 6 ) expressionValue(expression,tree,node);
		else 
		{
			buildTree(expression,tree,node,level + 1);
		}
	}
}