help with my file parser

[sundar0206]

Hi Guys,
I am writing a file parser for one of my code projects.. I have attached the code for my project

namespace Xlib {
	/*!Templating the class */
	template <class T>
	class Parser;
	
	template <class T>
	class FileParser {
 
		public:
			/*!	Default Constructor of the class	
			/param filename the name of the file that needs to be parsed
			*/
			FileParser(char *filename);
			/*!	Parsing the file
			/param line the line which has been read
			/param delimiters the delimiters to the file.
				*/
			void Parse(std::string& line,std::string& delimiters);
			/*! Searches the value of the passed in query*/
			void QueryKey(const char* key);
			
			/*! Get the key values
			/brief can u used for newer data types athat are not recognized
			*/
			std::vector<std::string>& get_AsString(){return token;}
			
			/*! Searches the Text file and returns the Query vector*/
			std::vector<std::string>& SearchandRetrieve(std::string& key){ QueryKey(key);	return get_AsString();}
			
			/* get values if u are searching for something specific..
	
			*/
			
			/*! Returns the second item of the 
			/param type the index of the element u want to retrieve.. 
			/brief say.. if u have Gravity : 9.8 0 2 it returns 9.8 if index is 1 0 if index is 2 and 2 if the index is 3
			/brief Requires query key to have been called before without which it would throw up junk or crash
			//TODO: 	Redo it so that we can automate the Query Key process*/
			T get_ValueasmyType(int index=1,std::ios_base& (*f)(std::ios_base&)=std::dec);
               
    
			
		private:
			/*!	File reader	*/
			std::fstream Parser;
			
			/*! The value of the parsed out variable */
			T* out;
					
			/*! A vector of string to recieve the parsed value */
			std::vector<std::string>  token;
			
		protected:
			/*	Nothing Protected */
 
	};//End of the class function; 
	
	//--------------------
	// Convenient typedefs
	//--------------------
	/*!defines the type to be float*/
	typedef Parser<float>	Parsef;
	/*!defines the type to be int*/
	typedef Parser<int>	Parsei;
	/*!defines the type to be float*/
	typedef Parser<double>	Parsed;
	/*!defines the type to be float*/
	typedef Parser<Xlib::vec3d>	Vector;

};//End of the namespace
 
 

#endif

My cpp file

#include "Parser.h"
#include <iostream>
#include "UTIL.h"

#include <cstring>
//Include header Files here 
//For reading in thetext

 
using namespace std;
using namespace Xlib;

template<class T>
FileParser<T>::FileParser(char *filename){
	Parser.open(filename,ios::in);
	if(!Parser.is_open())
		{
			Xlib::Error("Cant Open Parsing file");
			exit(EXIT_FAILURE);
		}
}


template<class T>
void FileParser<T>::QueryKey(const char* key){
	
	string buffer;
	string line;
	int strlength= strlen(key);
	token.clear();
	//TODO::: 
	while(!Parser.eof())
	{
		buffer.clear();
		getline(Parser,line,'\n');
		//can use getline with the line input and buffer output with delimiters
		buffer= line.substr(0,5);
		
		if(buffer==key)
		{
			Parse(line,": ");				
			return;
		}
		
		Error("The Search Query was not found.. Quit application for now.");
		DevMsg("This query is un available :", key);
		DevMsg("Try setting all values to Default May be i can go");
		exit(EXIT_FAILURE);
	}
	
}


template<class T>
void FileParser<T>::Parse(string& line,string& delimiters){
	unsigned int pos=line.find_first_not_of(delimiters,0);
	unsigned int lastpos=line.find_first_of(delimiters,pos);
	
	while(string::npos!= pos|| string::npos != lastpos)
		{
		token.push_back(line.substr(pos,lastpos-pos));
		pos=line.find_first_not_of(delimiters,lastpos);
		lastpos=line.find_first_of(delimiters,pos);		
		}	
}





template<class T>
T FileParser<T>::get_ValueasmyType(int index,std::ios_base& (*f)(std::ios_base&)){
	if(token.size()!=(index+1)){
		Error("Reading in the correct number of arguments", Parser, 75);
		return 0;
	}
	
	T i;
	if(quickstrConvert<T>(i,token[1],f)){
		return i;
	}
	else 
		Error("Error Found in conversion", Parser, 75);
		return 0;
}

I tried calling this function in the main loop like what I am giving now

	Parser myparse("1.log");
	myparse.QueryKey("Gravity");
	DevMsg("Testing ",myparse.get_ValueasmyType());

My text file 1.log is a simple test file which has jus this one line
Gravity:9.8


But This throws me errors like this
main.cpp: In function 'int main(int, char**)':
main.cpp:190: error: missing template arguments before 'myparse'
main.cpp:190: error: expected `;' before 'myparse'
main.cpp:191: error: 'myparse' was not declared in this scope

Can someone help me with where I have gone wrong?? And Ya DevMsg is a simple overload for cout statement i have wrote..

Is there somewhere I have gone wrong????

Regards

[potatoCode]

Hello

Please, write the smallest program that compiles (or the one that duplicates the error).
The error messages look somewhat familar, and I'm going to take a wild guess here that
it's probablly due to misplaced semi-colon, curly braces, incorrect header includes,
or the issue with a scope resolution.

For example, namespace doesn't end with a ;
that's one error you can correct.
std::ifstream's open() takes a const char*, so you might consider changing it.
I think it's a good practice to put things where they belong.
I'd consider putting all those typedefs in a seperate file,
possibly enclosed in the same namespace, or where Parser is declared,
so in this way you don't clutter FileParser which shows no relationship with Parser.
But what's bothering me the most is how you're using using directives to define your template class...

Edit:

template<class T>
T FileParser<T>::get_ValueasmyType(int index,std::ios_base& (*f)(std::ios_base&)){
	if(token.size()!=(index+1)){
		Error("Reading in the correct number of arguments", Parser, 75);
		return 0;
	}
	
	T i;
	if(quickstrConvert<T>(i,token[1],f)){
		return i;
	}
	else 
		Error("Error Found in conversion", Parser, 75);
		return 0;
}

I think, you might want to go over the return types for the method above.

[treuss]

	Parser myparse("1.log");

You declare Parser as a template class. You don't define Parser anywhere. You try to instantiate an object of that class without specifying the template argument?

It looks like you have not quite understoodd the concept of templates, yet, so I recommend to go back and do some reading and/or work on a real small example with a template class first.

[Peter_APIIT]

Besides that, you also define the template in another cpp file.

[Amleto]

yes, templates have to be implemented in the header ( or #included if you would like to still keep the implementation in a seperate file.)

then you need to instantiate with something like,

Parser<int> my ParserObj;