#ifndef LINESCANNER_H_
#define LINESCANNER_H_
// LineScanner is a simple one-type scanner class initialized
// from a single string. When that single string of input is
// consumed, it will throw a runtime_error. It scans only the
// provided type of values which must be able to use the >>
// extraction operator
// Beth Katz - September 2007

// Constructor
// LineScanner(const std::string & source)
//
// Mutator method
// T nextValue( )
//    returns the next value of type T if it exists
//    throws runtime_error if there is any problem
//
// Usage:
//    LineScanner<int> intScanner("5 -42 17 9");
//    string s = "Millersville University";
//    LineScanner<char> charScan(s);
//           would return individual characters skipping the space
//    LineScanner<string> strScan(s);
//           would return each of the two words one at a time

#include <string>
#include <sstream>
#include <stdexcept>

template <typename T>
class LineScanner {
public:
	explicit LineScanner(const std::string & source)
	: theStream(source) {
	}
	
	virtual ~LineScanner( ) {
	}
	
	virtual T nextValue( ) {
		T value;
	   
		if (theStream >> value) {
			return value; 
		} else {
			throw std::runtime_error("No more input.");
		}
	}
private:
	std::stringstream theStream;
};
#endif /*LINESCANNER_H_*/