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TextQueryRep.hpp

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/*==========================================================================
 * Copyright (c) 2001 Carnegie Mellon University.  All Rights Reserved.
 *
 * Use of the Lemur Toolkit for Language Modeling and Information Retrieval
 * is subject to the terms of the software license set forth in the LICENSE
 * file included with this software, and also available at
 * http://www.lemurproject.org/license.html
 *
 *==========================================================================
*/


#ifndef _TEXTQUERYREP_HPP
#define _TEXTQUERYREP_HPP

#include "RetrievalMethod.hpp"
#include "TextQuery.hpp"
#include "IndexedReal.hpp"
#include "Index.hpp"
#include "Counter.hpp"
#include "WeightedIDSet.hpp"
#include "FreqVector.hpp"

//------------------------------------------------------------
//      Abstract Interface for Text Query Representation 
//------------------------------------------------------------


class QueryTerm {
public:
  QueryTerm(TERMID_T termID, double weight) : ti(termID), w(weight) {
  } 
  virtual ~QueryTerm() {}
  virtual TERMID_T id() const { return ti;}
  virtual double weight() const { return w;}
protected:
  TERMID_T ti;
  double w;
};


class TextQueryRep : public QueryRep {
public:
  virtual ~TextQueryRep() {}
  virtual void startIteration() const = 0;
  virtual bool hasMore() const = 0;

  virtual QueryTerm *nextTerm() const = 0;

  virtual double scoreConstant() const = 0;

};





class ArrayQueryRep : public TextQueryRep {
public:
  ArrayQueryRep(int size) : ct(new ArrayCounter<double>(size)), scConst(0) {
  }
  ArrayQueryRep(int size, const TermQuery &qry, const Index &dbIndex);
  ArrayQueryRep(int size, const FreqVector &qryVec);

  virtual ~ArrayQueryRep() { delete ct; }


  virtual void startIteration() const {
    ct->startIteration();
  }

  virtual bool hasMore() const{
    return (ct->hasMore());
  }


  virtual QueryTerm *nextTerm() const;


  virtual void incCount(TERMID_T wdIndex, double count) {
    ct->incCount(wdIndex,count);
  }

  virtual void setCount(TERMID_T wdIndex, double count) {
    ct->setCount(wdIndex,count);
  }

  virtual double totalCount() const { return ct->sum();}

  virtual double scoreConstant() const{ return scConst;}

  virtual void setScoreConstant(double scoreConst) { scConst = scoreConst;}


protected:
  virtual QueryTerm *makeQueryTerm(TERMID_T wdIndex, double wdCount) const {
    return (new QueryTerm(wdIndex, wdCount));
  }
  double scConst;
  ArrayCounter<double> *ct;
};


class PseudoFBDocs : public DocIDSet {
public:
  PseudoFBDocs(IndexedRealVector &results, int howManyDoc, bool ignoreWeight=true):
    res(&results), howMany(howManyDoc), noWeight(ignoreWeight) {
  }
  virtual ~PseudoFBDocs() {}

  virtual void startIteration() const{
    it = res->begin();
    i=0;
  }  
  virtual bool hasMore() const;

  virtual void nextIDInfo(int &id, double &relProb) const;

private:
  mutable IndexedRealVector *res;
  int howMany;
  mutable int i;
  bool noWeight;
  mutable IndexedRealVector::iterator it;
};



#endif /* _TEXTQUERYREP_HPP */

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