// Tokenizer.h     Dave Reed      9/30/03
//
// Tokenizer class -- used to read tokens (language elements)
//     Note: utilizes the Token class from Token.h
//
//     constructor: create a Tokenizer connected to an input file
//       e.g., Tokenizer program("prog1.txt");
//
//      public member functions:
//         bool TokensRemain();     // returns true if tokens remain to be read
//         Token GetToken();        // returns next token from input stream
//         Token PeekAhead();       // returns next token without reading it
/////////////////////////////////////////////////////////////////////////////////

#ifndef _TOKENIZER_
#define _TOKENIZER_

#include <fstream>
#include <string>
#include "Token.h"
using namespace std;


class Tokenizer                             
{                                   
  public:
    Tokenizer(const string & filename);
    bool TokensRemain() const;
    Token GetToken();
    Token PeekAhead() const;
  private:
    Token nextToken;
    ifstream ifstr;
    bool remaining;
    bool ReadToken(Token & t);
};

#endif