C++ Element::getChildElement方法代码示例

/***************************************************************
* Function: CodeParser::parseCellArrayExpr()
* Purpose : Parse the XML code of a cell array expression
* Initial : Maxime Chevalier-Boisvert on February 23, 2009
****************************************************************
Revisions and bug fixes:
*/
Expression* CodeParser::parseCellArrayExpr(const XML::Element* pElement)
{
	// Declare a vector to store the rows
	CellArrayExpr::RowVector rowVector;

	// For each child element
	for (size_t i = 0; i < pElement->getNumChildren(); ++i)
	{
		// Declare a row to store elements
		CellArrayExpr::Row row;

		// Get a reference to this child element
		XML::Element* pRowElem = pElement->getChildElement(i);

		// If this is not a row element, throw an exception
		if (pRowElem->getName() != "Row")
			throw XML::ParseError("Invalid element found in cell array expression", pRowElem->getTextPos());

		// For each expression in this row
		for (size_t j = 0; j < pRowElem->getNumChildren(); ++j)
		{
			// Parse the expression and add it to the row
			row.push_back(parseExpression(pRowElem->getChildElement(j)));
		}

		// Add the row to the vector
		rowVector.push_back(row);
	}

	// Create and return the cell array expression
	return new CellArrayExpr(rowVector);
}

/***************************************************************
* Function: CodeParser::parseAssignStmt()
* Purpose : Parse the XML code of an assignment statement
* Initial : Maxime Chevalier-Boisvert on November 5, 2008
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseAssignStmt(const XML::Element* pElement)
{
	// Get the element corresponding to the left-expression
	XML::Element* pLeftElem = pElement->getChildElement(0);

	// Create a vector to store the left expressions
	AssignStmt::ExprVector leftExprs;

	// If the left expression is a matrix expression
	if (pLeftElem->getName() == "MatrixExpr")
	{
		// If the number of rows is not 1, throw an exception
		if (pLeftElem->getNumChildren() != 1)
			throw XML::ParseError("invalid matrix expression on assignment lhs");

		// Get the row element
		XML::Element* pRowElem = pLeftElem->getChildElement(0);

		// For each left expression element
		for (size_t i = 0; i < pRowElem->getNumChildren(); ++i)
		{
			// Get the child element for this expression
			XML::Element* pExprElem = pRowElem->getChildElement(i);

			// Parse this left-expression
			leftExprs.push_back(parseExpression(pExprElem));
		}
	}
	else
	{
		// Parse the left expression directly
		leftExprs.push_back(parseExpression(pLeftElem));
	}

	// Parse the right expression
	Expression* pRightExpr = parseExpression(pElement->getChildElement(1));

	// Get the output suppression flag
	bool suppressOut = pElement->getBoolAttrib("outputSuppressed");

	// Create and return the new assignment statement object
	return new AssignStmt(leftExprs, pRightExpr, suppressOut);
}

/***************************************************************
* Function: CodeParser::parseFunction()
* Purpose : Parse the XML code of a function
* Initial : Maxime Chevalier-Boisvert on November 3, 2008
****************************************************************
Revisions and bug fixes:
*/
ProgFunction* CodeParser::parseFunction(const XML::Element* pElement)
{
	// Get the function name
	std::string funcName = pElement->getStringAttrib("name");

	// Declare a pointer for the sequence statement
	StmtSequence* pSequenceStmt = NULL;

	// Declare vectors for the input and output parameters
	ProgFunction::ParamVector inParams;
	ProgFunction::ParamVector outParams;

	// Declare a vector for the nested function list
	ProgFunction::FuncVector nestedFuncs;

	// For each child element
	for (size_t i = 0; i < pElement->getNumChildren(); ++i)
	{
		// Get a pointer to this element
		XML::Element* pFuncElement = pElement->getChildElement(i);

		// If this is a symbol table
		if (pFuncElement->getName() == "Symboltable")
		{
			// Ignore for now
		}

		// If this is a parameter declaration list
		else if (pFuncElement->getName() == "ParamDeclList")
		{
			// Ignore for now
		}

		// If this is an input parameter list
		else if (pFuncElement->getName() == "InputParamList")
		{
			// For each child element
			for (size_t i = 0; i < pFuncElement->getNumChildren(); ++i)
			{
				// Get the parameter name
				const std::string& paramName = pFuncElement->getChildElement(i)->getStringAttrib("nameId");

				// Add the parameter to the list
				inParams.push_back(SymbolExpr::getSymbol(paramName));
			}
		}

		// If this is an output parameter list
		else if (pFuncElement->getName() == "OutputParamList")
		{
			// For each child element
			for (size_t i = 0; i < pFuncElement->getNumChildren(); ++i)
			{
				// Get the parameter name
				const std::string& paramName = pFuncElement->getChildElement(i)->getStringAttrib("nameId");

				// Add the parameter to the list
				outParams.push_back(SymbolExpr::getSymbol(paramName));
			}
		}

		// If this is a nested function list
		else if (pFuncElement->getName() == "NestedFunctionList")
		{
			// For each child element
			for (size_t i = 0; i < pFuncElement->getNumChildren(); ++i)
			{
				// Parse this function declaration
				ProgFunction* pFunction = parseFunction(pFuncElement->getChildElement(i));

				// Add the nested function to the list
				nestedFuncs.push_back(pFunction);
			}
		}

		// If this is the statement list
		else if (pFuncElement->getName() == "StmtList")
		{
			// If the statement list was already encountered, throw an exception
			if (pSequenceStmt != NULL)
				throw XML::ParseError("Duplicate statement list", pElement->getTextPos());

			// Parse the statement list
			pSequenceStmt = parseStmtList(pFuncElement);
		}

		// Otherwise
		else
		{
			// This is an invalid element type, throw an exception
			throw XML::ParseError("Invalid element type in script: \"" + pFuncElement->getName() + "\"", pFuncElement->getTextPos());
		}
	}
//.........这里部分代码省略.........

/***************************************************************
* Function: CodeParser::parseSwitchStmt()
* Purpose : Parse the XML code of a switch statement
* Initial : Maxime Chevalier-Boisvert on February 23, 2009
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseSwitchStmt(const XML::Element* pElement)
{
	// Parse the switch expression
	Expression* pSwitchExpr = parseExpression(pElement->getChildElement(0));

	// Declare a case list for the switch cases
	SwitchStmt::CaseList caseList;

	// Declare a statement sequence pointer for the default case
	StmtSequence* pDefaultCase = NULL;

	// For each remaining child element
	for (size_t i = 1; i < pElement->getNumChildren(); ++i)
	{
		// Get a pointer to this child element
		XML::Element* pChildElem = pElement->getChildElement(i);

		// If this is a switch case block
		if (pChildElem->getName() == "SwitchCaseBlock")
		{
			// Parse the switch case contents and add the case to the list
			caseList.push_back(
				SwitchStmt::SwitchCase(
					parseExpression(pChildElem->getChildElement(0)),
					parseStmtList(pChildElem->getChildElement(1))
				)
			);
		}

		// If this is a default case block
		else if (pChildElem->getName() == "DefaultCaseBlock")
		{
			// If a default case was already parsed
			if (pDefaultCase != NULL)
			{
				// Throw an exception
				throw XML::ParseError("Duplicate default case in switch statement", pChildElem->getTextPos());
			}

			// Parse the statement list
			pDefaultCase = parseStmtList(pChildElem->getChildElement(0));
		}

		// Otherwise
		else
		{
			// This is an invalid element type, throw an exception
			throw XML::ParseError("Invalid element in switch statement: \"" + pChildElem->getName() + "\"", pChildElem->getTextPos());
		}
	}

	// If there is no default case, create an empty one
	if (pDefaultCase == NULL)
		pDefaultCase = new StmtSequence();

	// Create and return the switch statement object
	return new SwitchStmt(
		pSwitchExpr,
		caseList,
		pDefaultCase
	);
}

/***************************************************************
* Function: CodeParser::parseIfStmt()
* Purpose : Parse the XML code of an if statement
* Initial : Maxime Chevalier-Boisvert on November 5, 2008
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseIfStmt(const XML::Element* pElement)
{
	// Declare a vector to store the if blocks
	std::vector<XML::Element*> ifBlocks;

	// Declare a pointer for the else block
	XML::Element* pElseBlock = NULL;

	// For each child element
	for (size_t i = 0; i < pElement->getNumChildren(); ++i)
	{
		// Get a pointer to this element
		XML::Element* pIfElement = pElement->getChildElement(i);

		// If this is an if block
		if (pIfElement->getName() == "IfBlock")
		{
			// Add it to the list
			ifBlocks.push_back(pIfElement);
		}

		// If this is an else block
		else if (pIfElement->getName() == "ElseBlock")
		{
			// If there is more than one else block, throw an exception
			if (pElseBlock)
				throw XML::ParseError("Duplicate else block", pIfElement->getTextPos());

			// Store a pointer to the else block
			pElseBlock = pIfElement;
		}

		// Otherwise
		else
		{
			// This is an invalid element type, throw an exception
			throw XML::ParseError("Invalid element in if statement: \"" + pIfElement->getName() + "\"", pIfElement->getTextPos());
		}
	}

	// If are are no if blocks, throw an exception
	if (ifBlocks.size() == 0)
		throw XML::ParseError("Missing if block", pElement->getTextPos());

	// Get a pointer to the last if block
	XML::Element* pLastIfBlock = ifBlocks.back();

	// remove the last if block from the list
	ifBlocks.pop_back();

	// Create the first if-else statement from the last if and else blocks
	IfElseStmt* pIfStmt = new IfElseStmt(
			parseExpression(pLastIfBlock->getChildElement(0)),
			parseStmtList(pLastIfBlock->getChildElement(1)),
			pElseBlock? parseStmtList(pElseBlock->getChildElement(0)):(new StmtSequence())
	);

	// For each if block, in reverse order
	for (std::vector<XML::Element*>::reverse_iterator itr = ifBlocks.rbegin(); itr != ifBlocks.rend(); ++itr)
	{
		// Get a pointer to this if block element
		XML::Element* pIfBlock = *itr;

		// Add this if block to the recursive structure
		pIfStmt = new IfElseStmt(
			parseExpression(pIfBlock->getChildElement(0)),
			parseStmtList(pIfBlock->getChildElement(1)),
			new StmtSequence(pIfStmt)
		);
	}

	// Return a pointer to the if-else statement
	return pIfStmt;
}