in.h

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// ============================================================================
// Project:     Deductive Database
// Filename:    in.h
// Purpose:     Abstract Input Source (e.g. File, CGI, Keyboard)
// Last Change: 01.08.2017
// 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) 1998-2017 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 IN_INCLUDED
#define IN_INCLUDED

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

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

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

//=============================================================================
// Class for Input Source:
//=============================================================================

class in_c {
        public:

//-----------------------------------------------------------------------------
// Destructor:
//-----------------------------------------------------------------------------

        virtual inline ~in_c()
                {};

//-----------------------------------------------------------------------------
// read: Read characters from input file into buffer.
//-----------------------------------------------------------------------------

        virtual int     read(char *buf, int size) = 0;

//-----------------------------------------------------------------------------
// is_open: This is really an open input stream (i.e. opening was successful).
//-----------------------------------------------------------------------------

        virtual bool    is_open() = 0;

//-----------------------------------------------------------------------------
// close: Close input file explicitly.
//-----------------------------------------------------------------------------

        virtual bool    close() = 0;

//-----------------------------------------------------------------------------
// filename: Name of this file (if it is a file).
//-----------------------------------------------------------------------------

        virtual str_t   filename() = 0;

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

};

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

typedef in_c *in_t;

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

#define IN_NULL (static_cast<in_t>(0))

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

#endif