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PredicateTree.h

                              /* PredicateTree.h */

#ifndef  PREDICATE_TREE_HH  
#define  PREDICATE_TREE_HH  

#include <string>
#include <vector>
#include <set>
#include <iostream>
#include "QueryTranslationException.h"
#include "TableRowTranslator.h"


namespace LcgInfo{
/************************************  CLASS PredicateTree  ***********************************/

class PredicateTree{

   //No copy constructor
   PredicateTree(PredicateTree & other);

public:
   enum NodeType{
      BOOLEAN,
      COMPARISON,
      LEAF
   };

   PredicateTree();   

   virtual ~PredicateTree();

   virtual PredicateTree* create()=0;

   virtual PredicateTree * clone()=0;

   bool const PredicateTree::operator==(PredicateTree const & other);

   void clear();

   bool empty();

   NodeType type() const {return mType;}
   std::string value() const {return mValue;}

   void translate(TableRowTranslator * pTRowT, std::vector<std::string> * pOrgTables,
                  std::set<std::string> * pNewTables);

   void print();

   virtual void insertPredicate(std::string const & pPred)=0;

    virtual std::string evaluate(std::vector<std::string> & pQueries)=0;

   int depth() const {return mDepth;}
   PredicateTree* left() const {return mLeft;}
   PredicateTree* right() const {return mRight;}
   void setType(NodeType const & pType) {mType=pType;}
   void setValue(std::string const & pValue) {mValue=pValue;}
   void setDepth(int pDepth) {mDepth=pDepth;}
   void setLeft(PredicateTree* pLeft=NULL);
   void setRight(PredicateTree* pRight=NULL);

   void incrementDepth(int pAmount);

   bool relatesTables();
   bool isIdentity() const;   
   
   bool isRedundant(PredicateTree const & pPred);

   void addAndPredicate(std::string const& pPred, std::set<std::string> & pNewTables);

   bool isBooleanOp(std::string pStr);
   
protected:
   virtual std::string getCHARS_TO_TOKENIZE_PREDICATES();


private:
   NodeType mType;
   std::string mValue;
   int mDepth;
   PredicateTree* mLeft;
   PredicateTree* mRight;

/*
 * The chars that have to be escaped in the literals, so that they are not
 * interpreted as special characters (comparison operators...).  
 */
static std::string const CHARS_TO_ESCAPE_IN_LITERALS;

};

}
#endif

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