Use std::string instead destructed char*

FormulaParser.cpp

@@ -439,19 +439,13 @@ namespace ExcelFormula
 			}
 
 			if ((pToken->getType() == Token::Operand) && (pToken->getSubtype() == Token::Nothing)) {
-				double d;
-				//bool isNumber = double.TryParse(pToken.Value, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.CurrentCulture, out d);
-				stringstream doubleConv;
-				doubleConv << pToken->getValue();
-				doubleConv >> d;
-
-				if (doubleConv.fail())
-					if ((pToken->getStrValue().compare("TRUE") == 0) || (pToken->getStrValue().compare("FALSE") == 0)) 
-						pToken->setSubtype(Token::Logical);
-					else 
-						pToken->setSubtype(Token::Range);            
+				if (StrUtils::is_number(pToken->getStrValue()))
+					pToken->setSubtype(Token::Number);
 				else
-					pToken->setSubtype(Token::Number);          
+					if ((pToken->getStrValue().compare("TRUE") == 0) || (pToken->getStrValue().compare("FALSE") == 0))
+						pToken->setSubtype(Token::Logical);
+					else
+						pToken->setSubtype(Token::Range);
 
 				m_tmpAry.add(pToken);
 				continue;

StrUtils.cpp

@@ -34,6 +34,13 @@ string StrUtils::trim(string& value)
 	return value;
 } //fn trim
 
+bool StrUtils::is_number(const std::string& s)
+{
+    std::string::const_iterator it = s.begin();
+    while (it != s.end() && std::isdigit(*it)) ++it;
+    return !s.empty() && it == s.end();
+}
+
 bool StrUtils::isEmpChar(const char c)
 {
 	static const char empChar[] = {' ', '\t'};

StrUtils.h

@@ -24,6 +24,8 @@ class StrUtils
 		static int indexOf(vector<string>&, string&);
 		static int indexOf(const int, const char*[], const char*);
 
+    static bool is_number(const std::string& s);
+
 	private:
 		static bool isEmpChar(const char);
 

Token.cpp

@@ -28,7 +28,7 @@ namespace ExcelFormula
 	}
 
 	//! return printable string
-	const char* Token::getPrintableString()
+	const string Token::getPrintableString()
 	{
 		string printableStr = m_value + " ";
 
@@ -104,7 +104,7 @@ namespace ExcelFormula
 				printableStr += "<Union>";
 				break;
 		}//token subtype switch
-		return printableStr.c_str();
+		return printableStr;
 	} //func  getPrintableStr
 
 	Token* Token::clone()

Token.h

@@ -80,7 +80,7 @@ namespace ExcelFormula
 			}
 
 			//! get printable token string
-			const char* getPrintableString();
+			const string getPrintableString();
 
 			//! duplicate a another token
 			Token* clone();

main.cpp

@@ -8,7 +8,7 @@ using std::string;
 using ExcelFormula::Token;
 using ExcelFormula::FormulaParser;
 
-void printIntend(int i)
+void printIndent(int i)
 {
 	for(int j = 0; j < i; ++j)
 	{
@@ -23,20 +23,20 @@ void printParser(FormulaParser& parser)
 	cout << "Formula:" << parser.getFormula() << endl;
 	cout << "Tokens:" << endl;
 
-	int intend = 0;
+	int indent = 0;
 	for(vector<Token*>::iterator it = tokens.begin();
 			it != tokens.end();
 			++it)
 	{
 		if((*it)->getSubtype() == Token::Start)
 		{
-			++intend;
+			++indent;
 		}
-		printIntend(intend);
+		printIndent(indent);
 		cout << (*it)->getPrintableString() << endl;
 		if((*it)->getSubtype() == Token::Stop)
 		{
-			--intend;
+			--indent;
 		}
 	}