#ifndef CPPTOKER_H  // compile if CPPTOKER_H is not in symbol table
#define CPPTOKER_H  // put CPPTOKER_H in symbol table
/////////////////////////////////////////////////////////////////////////
// CppToker.h - declares tokenizer which extracts words from a stream  //
// ver 1.0                                                             //
// Language:    Visual C++, ver 7.0                                    //
// Platform:    Dell Dimension 8300, Windows XP Prof, SP 1             //
// Application: CSE687 prototype for project #1, Spring 2004           //
// Author:      Jim Fawcett, CST 2-187, Syracuse University            //
//              (315) 443-3948, jfawcett@twcny.rr.com                  //
/////////////////////////////////////////////////////////////////////////
/*
 * Module Operations:
 * ==================
 * CppToker.h Declares a class CToker designed to extract words from a 
 * std stream.  Each word is either an identifier or punctuator token.
 * Identifiers consist of alphabetic characters, digits, and underscores.
 * Punctuators are composed of all other non-whitespace characters.  A
 * specific set of punctuation characters are designated as single character
 * tokens.  All other non-identifiers consist of multiple punctuators.
 *
 * Public Interface:
 * =================
 * std::fstream in(someFile);
 * CToker toker(&in);                           // create toker
 * std::string tok;
 * while((tok = toker.getTok()) != "")          // read tokens
 *  // do something with tok
 * std::istream *pStr = toker.getStream();      // get pointer to stream
 * std::istream *pOld = toker.setStream(pNew);  // give toker new stream
 * std::string curr = toker.curr();             // get last token extracted
 * std::string prev = toker.prev();             // get one before that
 */
/*
 * Maintenance History:
 * ====================
 * ver 1.0 : 12 Jan 04
 *   - first release
 *
 * Build Process:
 * ==============
 * Required Files:
 *   CppToker.h, CppToker.cpp
 *
 * Compiler Command:
 *   cl /DTest_CPPTOKER /EHsc CppToker.cpp;
 */
//
/*
 * Design Notes:
 * =============
 * This module illustrates many things we will be covering this semester, some
 * rather unusual things, for purposes of illustration:
 *   - the type std::basic_string<char> appears in this header file.  You will
 *     usually see the type std::string in most C++ code, which is equivalent.
 *     This syntax makes it clear that the standard string is a template-based
 *     type, using the 8 bit Char type as part of its definition.  We will be
 *     saying much more about this later in the course.
 *   - The CToker class has a private helper class, CTokBuffer, and declares a
 *     reference to that type.  This prevents CToker class from participating
 *     in copy or assignment operations.  That is consistent with my intended
 *     abstraction for this class.
 *   - I wanted to keep CTokBuffer out of the abstraction of the CToker class
 *     For that reason its declaration is in the implementation file,
 *     CppToker.cpp, instead of in this header file.  A consequence of that is
 *     that the CToker class cannot hold an object of CTokBuffer, because its
 *     size is not known to the compiler yet.  It could hold either a pointer
 *     or a reference to its CTokBuffer instance.  I chose to use a reference
 *     so that I could use object semantics rather than pointer semantics in 
 *     the CToker member function implementations.
 */

#include <iostream>
#include <vector>
#include <string>
#include <set>

namespace Project1
{
  ///////////////////////////////////////////////////////////////////////
  // class CToker - extracts tokens from a std stream
  //              - uses a private CTokBuffer class to help build
  //                tokens from stream

  class CToker
  {
  public:
    CToker(std::basic_istream<char> *pStream=0);
    ~CToker(void);
    std::istream* setStream(std::basic_istream<char> *pStream);
    std::basic_string<char> getTok();
    std::istream* getStream();
    std::basic_string<char> prev();
    std::basic_string<char> curr();
  private:
    std::istream *_pStream;
   // forward reference to helper class
    class CTokBuffer;
   // reference type below will prevent CToker objects
   // being copied or assigned
    CTokBuffer &tokBuffer;
    std::basic_string<char> prevTok;
    std::basic_string<char> currTok;
  };
}
#endif