{

public:

ExpressionParser()

: _expression(NULL)

{

}

CustomExpression* _expression;

bool IsDecimal(CStringW& str);

bool IsDecimal(wchar_t chr, bool& exponential);

bool IsDecimalZero(CStringW& str);

bool IsInteger(CStringW& str);

bool IsOperator(wchar_t s);

bool IsOperator(CStringW s);

bool IsFunctionName(wchar_t s);

bool ParseTree(CStringW s);

CustomFunction* ParseFunction(CStringW& s, int begin, int& fnBegin);

bool ParseArgumentList(CStringW s, CustomFunction* fn);

bool GetBrackets(CStringW expression, int& begin, int& end, CStringW openingSymbol = "(", CStringW closingSymbol = ")");

CStringW GetInnerString(CStringW& s, int begin, int end);

CExpressionPart* ParseExpressionPart(CStringW s);

bool ReadValue(CStringW s, int& position, CElement* element);

bool ReadOperation(CStringW s, int& position, CElement& element);

void ReplacePart(CStringW& s, int begin, int end);

bool ReplaceStringLiterals(CStringW& s, int& count);

bool ReplaceFieldNames(CStringW& s, int& count);

void ReplaceSubString(CStringW& s, int begin, int length, CStringW replacement);

void SetErrorMessage(CStringW msg) { _expression->SetErrorMessage(msg); }

void SetErrorPosition(int position) { _expression->SetErrorPosition(position); }

bool Parse(CustomExpression* expression, CStringW s, bool useFields);

bool ReplaceParameterlessFunctions(CStringW& s);