//****************************************************************//
//                                                                //
// Copyright (c) 1997.                                            //
//      Dr. Michael A. Redmond                                    //
//                                                                //
// This software may not be distributed further without permission from     //
// Dr Michael A. Redmond.                                         //
//                                                                //
// This software is distributed WITHOUT ANY WARRANTY. No claims are made    //
// as to its functionality or purpose.                            //
//                                                                //
// Title: Tw_Color.h
// Use:   Provides abstraction for the color of pegs and links
//        for twixt
// Author: Dr Michael A. Redmond                            //
// Date: 3/05/97                                                  //
//                                                                //
//
//**************************************************************************//

// tw-color.h: declaration of Tw_Color ADT
// conditional compilation to avoid trying to include same thing twice
#ifndef TW_COLOR_H
#define TW_COLOR_H

#include <iostream.h>

enum color {empty, black, white, illegal};

const color badcolor = illegal;

// Tw_Color ADT: class description
// Defines class and its interface to the world
//    implementation is in tw-color.cpp
class Tw_Color {
        // public interface can be used by anybody
	public: // member functions
		// constructor - color defaults to empty
		Tw_Color(color col = empty);
		// inspectors               
                color GetColor() const;
                color GetRevColor() const;
                // returns a one char abreviation for the color
                //    like insert but returns the char instead of putting it in
                //    the output stream
                char GetCharRep() const;
		// mutators -  establish new values of attributes (data members)
                void SetColor(color col);
                void RevColor();
		// facilitators
		// some stream facilitators
                // write to stream
		void Insert(ostream &sout) const;
                // read from stream
		void Extract(istream &sin);
	protected:
		// inspectors
		// mutators
                // facilitators
	private:
		// data members
		color colorv;
};

// below overloads standard c++ operators so that they can be used 
// with tw_color class objects, so syntax is like with ints floats etc
//
// Tw_Color ADT: auxiliary operator description

ostream& operator<<(ostream &sout, const Tw_Color &s);
istream& operator>>(istream &sin, Tw_Color &r);
bool operator==(const Tw_Color &left, const Tw_Color &right);
bool operator!=(const Tw_Color &left, const Tw_Color &right);
bool operator!=(const Tw_Color &left, const color &right);

#endif