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Tokenizer and analyzer package supporting precedence prioritized rules

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1 Jan 20023 min read 180.7K   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:      cxTokenizerMap
Author:     Alexander Berthold
Copyright:  Alexander Berthold
Date:       2001/12/19
Version:	0.2.01
Purpose:    Container class for the nested maps of rules.
            A short explanation:

            - There a two different sets of rules: 'first position'
              rules and 'within' rules. 'within' rules can appear
              anywhere, like the C++ bracket ('(') token. 'First position' rules
              are those which apply only to a complete string. Sample:

              return(5);

              Here, '(' is found and breaks the input text into
              'return' and '('. If there is a 'first position' rule which
              matches 'return', it is used and recognized. If not, the
              'NULL' rule applies.

            - To speed up the recognition process, all rules which could
              apply are tested in parallel. C++ operators '=' and '==', 
              for example, both start with the same character. So the
              tokenizer finds if it happens to read a '=' both rules
              could be valid. If the next token is _not_ another '=',
              it recognizes an '=' token. If it _is_ '=', then the
              '==' token is recognized.

            - This is done by traversing a tree structure, which 
              would look like this for the tokens 'if', 'elseif', 'else'
              and 'endif':

              1st  2nd  3rd  4th  5th  6th  7th

              'i'--'f'--(*)

              'e'--'l'--'s'--'e'--(*)
               |              |
               |              +---'i'--'f'--(*)
               |
               +---'n'--'d'--'i'--'f'--(*)

              (*) stands for a recognized token.


Version history:

	-	2001/05/19
		Renamed class from 'cpLexxerMap' to 'cxTokenizerMap'.

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

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

#if !defined(AFX_CXTOKENIZERMAP_H__F4E70A9E_72B3_4707_85A1_C5FDB8CE26C3__INCLUDED_)
#define AFX_CXTOKENIZERMAP_H__F4E70A9E_72B3_4707_85A1_C5FDB8CE26C3__INCLUDED_

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

class cxTokenizerInputStream;

class cxTokenizerMap :
	public ctkCheckValid
{
// Construction/Destruction
public:
	cxTokenizerMap();
	cxTokenizerMap(std::basic_istream<TCHAR>& input);
	virtual ~cxTokenizerMap();

// Typedefs
public:
	typedef std::vector<cxTokenizerTokenRule*>
						ttrdel_vec_type;

// Attributes
protected:
	// Already initialized?
	bool				m_fInitialized;

	// Map of rules which apply only from the first character of a new token
	// (FP = first position)
	cxTokenizerMapData	m_tmdFPRules;
	// Map of rules which can appear also within other tokens (WI=within)
	cxTokenizerMapData	m_tmdWIRules;

	ttrdel_vec_type		m_vecRulesToDelete;

// Protected operations
protected:
	bool			fRegisterCharRule(cxTokenizerMapData& maptRules, 
									  cxTokenizerCharTokenRule* pRule,
									  cxTokenizerMapData **pptmdEnd = NULL);
	bool			fRegisterComputedRule(cxTokenizerMapData& maptRules, 
										  cxTokenizerTokenRule* pRule);

// ctkCheckValid operations
public:
#ifdef _DEBUG
	virtual bool	fCheckValid() const;
	static bool		fRunDiagnostics();
#else
	virtual bool	fCheckValid() const { return true; };
#endif

// Operations
public:
	bool			fRegisterRule(cxTokenizerTokenRule* pRule);

	const cxTokenizerMapData* ptmdGetFPRules() const { return &m_tmdFPRules; };
	const cxTokenizerMapData* ptmdGetWIRules() const { return &m_tmdWIRules; };
	const cxTokenizerTokenRule* pttrGetRuleForID(int nIDValue) const;
	const cxTokenizerTokenRule* pttrGetRuleForString(const std::tstring& strToken) const;

	bool			fBuildRule(int nIDValue, const std::tstring strToken, const std::tstring& strInitString, bool fSeperator);
    bool			fBuildHybridRule(int nIDValue, const std::tstring strToken, const std::tstring& strInitString, bool fSeperator, cxTokenizerTokenRule *pRule);
	void			vLoadFromStream(std::basic_istream<TCHAR>& input);
	void			vInitNotify(bool fInit, cxTokenizer *pxTokenizer);

	friend class cxTokenizer;
};

#endif // !defined(AFX_CXTOKENIZERMAP_H__F4E70A9E_72B3_4707_85A1_C5FDB8CE26C3__INCLUDED_)

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