atom.h

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// ============================================================================
// Project:     Deductive Database
// Filename:    atom.h
// Purpose:     Atoms (Symbolic Constants, Enumeration Type Constants)
// Last Change: 04.08.2017
// Language:    C++
// EMail:       brass@informatik.uni-halle.de
// WWW:         http://www.informatik.uni-halle.de/~brass/
// Address:     Feldschloesschen 15, D-06120 Halle (Saale), GERMANY
// Copyright:   (c) 2015-2017 by Stefan Brass
// License:     See file "LICENSE" for copying conditions.
// Note:        There is no warranty at all - this code may contain bugs.
// ============================================================================


//=============================================================================
// Include File Frame:
//=============================================================================

#ifndef ATOM_INCLUDED
#define ATOM_INCLUDED

//=============================================================================
// Used Types and Macros:
//=============================================================================

#ifndef VER_INCLUDED
#include "../base/ver.h"
#endif

#ifndef STR_INCLUDED
#include "../base/str.h"
#endif

#ifndef CHECK_INCLUDED
#include "../base/check.h"
#endif


//=============================================================================
// Private Constants:
//=============================================================================

//-----------------------------------------------------------------------------
// ATOM_MAGIC: Magic number (identifies objects of this class).
//-----------------------------------------------------------------------------

static const long ATOM_MAGIC = 0x41544F0AL;     // 'ATO\n'


//=============================================================================
// Class for Atoms (Symbolic Constants, Enumeration Type Constants)
//=============================================================================

class atom_c {
        public:


//-----------------------------------------------------------------------------
// Constructor, Destructor:
//-----------------------------------------------------------------------------

        // Constructor (Not implemented, use init() instead, see atomtab_c):
        atom_c();

//      // Destructor:
//      ~atom_c();


//-----------------------------------------------------------------------------
// (Object) Methods:
//-----------------------------------------------------------------------------

        // init: Used in place of the constructor.
        void init(str_t name_start, str_t name_end, int atom_id, atom_c *next);
                // atom_id is returned by id()
                // next is returned by hash_next()
                // gcc complained about shadowed names.

        // name: Return name of atom.
        str_t name() {
                CHECK_VALID("atom_c::name");
                return Name;
        }

        // id: Return number of this atom (unique within one atomtab_c).
        int id() {
                CHECK_VALID("atom_c::id");
                return Id;
        }

        // hash_next: Return next atom in hash chain.
        atom_c* hash_next() {
                CHECK_VALID("atom_c::hash_next");
                return HashNext;
        }


//-----------------------------------------------------------------------------
// Debugging Support:
//-----------------------------------------------------------------------------

#if     VER_DEBUG
        // Integrity check:
        public:
        str_t   check() const;

        // Magic number (identifies objects of this class for debugging).
        private:
        long    Magic;          // Must be "ATOM_MAGIC".
#endif


//-----------------------------------------------------------------------------
// Copy-constructor and assignment operator are not supported for this class:
//-----------------------------------------------------------------------------

        private:

        atom_c(const atom_c& atom);             // Not implemented
        atom_c& operator=(const atom_c& atom);  // Not implemented



//-----------------------------------------------------------------------------
// Private Object Members:
//-----------------------------------------------------------------------------

        private:

        // Name of this atom:
        char Name[VER_MAX_ATOMSIZE+1];

        // Number of this atom (will be unique within one atomtab_c):
        int Id;

        // Link to next atom in hash chain (see class atomtab_c).
        atom_c *HashNext;


//=============================================================================
// End of Class:
//=============================================================================

};

//-----------------------------------------------------------------------------
// Define pointer type:
//-----------------------------------------------------------------------------

typedef atom_c *atom_t;

//-----------------------------------------------------------------------------
// Define null pointer:
//-----------------------------------------------------------------------------

#define ATOM_NULL (static_cast<atom_t>(0))

//=============================================================================
// End of Include File:
//=============================================================================

#endif