Click here to Skip to main content
15,867,330 members
Articles / Programming Languages / C++

Tokenizer and analyzer package supporting precedence prioritized rules

Rate me:
Please Sign up or sign in to vote.
5.00/5 (4 votes)
1 Jan 20023 min read 180.1K   2.8K   54  
A library allowing you to conveniently build a custom tokenizer and analyzer supporting precedence priorized rules
/*********************************************************************
	Copyright (C) 2001/2 by

		Alexander Berthold, alexander-berthold@web.de.
		Hoegestr. 54
		79108 Freiburg i. Breisgau
		Germany

    -- This file is part of cxTokenizer --

    "cxTokenizer" is free software; you can redistribute it and/or 
	modify it under the terms of the GNU Lesser General Public 
	License as published by the Free Software Foundation; either 
	version 2 of the License, or any later version.

    "cxTokenizer" is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
	License along with "cxTokenizer"; if not, write to the Free 
	Software  Foundation, Inc., 59 Temple Place, Suite 330, 
	Boston, MA  02111-1307  USA

    ---------------------------------------------------------------
      If you find any bugs or if you make other corrections/
	  enhancements, i'd appreciate if you'd let me know about 
	  that. My email is
  
       alexander-berthold@web.de
  
      If you share this code, do not remove this text.
    ---------------------------------------------------------------

Class:      cxTokenizerTextInputStream
Author:     Alexander Berthold
Copyright:  Alexander Berthold
Date:       2001/12/19
Version:	0.2.01
Purpose:    Sample input stream class for the parser.
            Takes a LPCTSTR as constructor argument and creates
            a cxTokenizerInputStream compatible stream out of it.


Version history:

	-	2001/05/19
		Renamed class from 'cpLexxerTextInputStream' to 
		'cxTokenizerTextInputStream'.

	-	2001/06/02
		Current source labeled version 0.1.14

	-	2001/06/03
		Changed base class from cxTokenizerInputStream to
		cxTokenizerInputStreamDefaultImpl and made the necessary
		modifications in the code.
		See cxTokenizerInputStreamDefaultImpl.

	-	2001/12/19
		Current source labeled version 0.2.01
				
*********************************************************************/

// cxTokenizerTextInputStream.h: interface for the cxTokenizerTextInputStream class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_CXTOKENIZERTEXTINPUTSTREAM_H__CB2EA5EA_2239_4926_B7BF_6CC6972A3E14__INCLUDED_)
#define AFX_CXTOKENIZERTEXTINPUTSTREAM_H__CB2EA5EA_2239_4926_B7BF_6CC6972A3E14__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

template<class TBase>
class cxTokenizerTextInputStream : public TBase
{
// Construction/Destruction
public:
	cxTokenizerTextInputStream(const TCHAR* lpszInputData, bool fShouldDelete = false)
		{
		m_strInputData	=lpszInputData;
		m_strPutBackData=_T("");
		m_nInputPos		=0;
		m_nPutBackPos	=0;
		m_fShouldDelete	=fShouldDelete;
		}

	virtual ~cxTokenizerTextInputStream()
		{
		}

// Attributes
protected:
	std::tstring	m_strInputData;
	int				m_nInputPos;
	std::tstring	m_strPutBackData;
	int				m_nPutBackPos;
	bool			m_fShouldDelete;

// Protected operations
protected:
	virtual bool	fReadBlock(long lStartPos, long lLength, std::tstring& strResult, TCHAR tcTermChar) const
		{
		ASSERT(lLength>=0);
		ASSERT(lStartPos>=0);
		long		lPos, lCnt = 0;
		long		lInputLength = m_strInputData.length();
		strResult	=_T("");
		ASSERT(lStartPos<=lInputLength);

		if( lStartPos == lInputLength)
			return true;

		for(lPos = lStartPos; lCnt<lLength && lPos<lInputLength; lPos++, lCnt++)
			{
			TCHAR	tcTemp = m_strInputData[lPos];

			if(tcTemp==tcTermChar)
				break;
			
			strResult	+=tcTemp;
			}

		return true;
		};

// Operations
public:
	virtual	bool	fCheckValid() const
		{
		return true;
		}

	virtual TCHAR	tcPeekNextCharacter() const
		{
		int		nPutBackLength = m_strPutBackData.length();
		TCHAR	tcReturn = _T('\0');
		bool	fEof = fIsEofReached();

		if(fEof)
			return 0;

		if(m_nPutBackPos < nPutBackLength)
			tcReturn	=m_strPutBackData[m_nPutBackPos];
		else
			tcReturn	=m_strInputData[m_nInputPos];

		return tcReturn;
		}

	virtual TCHAR	tcGetNextCharacter()
		{
		int		nPutBackLength = m_strPutBackData.length();
		TCHAR	tcReturn = _T('\0');
		bool	fEof = fIsEofReached();

		ASSERT(!fEof);
		if(fEof)
			throw cxTokenizerException(ERR_READ_PAST_EOF);

		if(m_nPutBackPos < nPutBackLength)
			{
			tcReturn	=m_strPutBackData[m_nPutBackPos++];
			if(m_nPutBackPos == nPutBackLength)
				{
				m_nPutBackPos	=0;
				m_strPutBackData=_T("");
				}
			}
		else
			{
			tcReturn	=m_strInputData[m_nInputPos++];
			}

		return tcGetNextCharacterDefaultImpl(tcReturn);
		}

	virtual bool	fPutBack(LPCTSTR lpszText)
		{
		m_strPutBackData.insert(0,lpszText);
		return fPutBackDefaultImpl(lpszText);
		}

	virtual bool	fPutBack(TCHAR tcChar)
		{
		// Compatibility with STLport 4.0 ->
		TCHAR		szTemp[2] = { 0,0 };
		szTemp[0]	=tcChar;
		m_strPutBackData.insert(0,szTemp);
		return fPutBackDefaultImpl(tcChar);
		}

	virtual bool	fIsEofReached() const
		{
		int		nInputLength = m_strInputData.length();
		int		nPutBackLength = m_strPutBackData.length();

		if(	(m_nPutBackPos == nPutBackLength) &&
			(m_nInputPos == nInputLength))
			return true;

		return false;
		}

	virtual bool	fShouldDelete() const
		{
		return m_fShouldDelete;
		}
};

#endif // !defined(AFX_CXTOKENIZERTEXTINPUTSTREAM_H__CB2EA5EA_2239_4926_B7BF_6CC6972A3E14__INCLUDED_)

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
Web Developer
Germany Germany
This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.

Comments and Discussions