FWExpressionEvaluator.cc

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// -*- C++ -*-
//
// Package:     Core
// Class  :     FWExpressionEvaluator
//
// Implementation:
//     <Notes on implementation>
//
// Original Author:  Chris Jones
//         Created:  Fri Feb 29 13:39:56 PST 2008
// $Id: FWExpressionEvaluator.cc,v 1.5 2012/08/03 18:20:28 wmtan Exp $
//

// system include files
#include <sstream>

#include "FWCore/Utilities/interface/ObjectWithDict.h"

// user include files
#include "Fireworks/Core/interface/FWExpressionEvaluator.h"
#include "Fireworks/Core/interface/FWExpressionException.h"
#include "CommonTools/Utils/src/Grammar.h"
#include "CommonTools/Utils/interface/Exception.h"

#include "Fireworks/Core/src/expressionFormatHelpers.h"

//
// constants, enums and typedefs
//

//
// static data member definitions
//

//
// constructors and destructor
//
FWExpressionEvaluator::FWExpressionEvaluator(const std::string& iExpression,
                         const std::string& iClassName) :
   m_className(iClassName),
   m_type(edm::TypeWithDict::byName(iClassName))
{
   setExpression(iExpression);
}

// FWExpressionEvaluator::FWExpressionEvaluator(const FWExpressionEvaluator& rhs)
// {
//    // do actual copying here;
// }

FWExpressionEvaluator::~FWExpressionEvaluator()
{
}

//
// assignment operators
//
// const FWExpressionEvaluator& FWExpressionEvaluator::operator=(const FWExpressionEvaluator& rhs)
// {
//   //An exception safe implementation is
//   FWExpressionEvaluator temp(rhs);
//   swap(rhs);
//
//   return *this;
// }

//
// member functions
//
void
FWExpressionEvaluator::setExpression(const std::string& iExpression)
{
   if(m_type != edm::TypeWithDict() && iExpression.size()) {
      using namespace fireworks::expression;

      //Backwards compatibility with old format
      std::string temp = oldToNewFormat(iExpression);

      //now setup the parser
      using namespace boost::spirit::classic;
      reco::parser::ExpressionPtr tmpPtr;
      reco::parser::Grammar grammar(tmpPtr,m_type);
      try {
         if(parse(temp.c_str(), grammar.use_parser<1>() >> end_p, space_p).full) {
            m_expr = tmpPtr;
            m_expression = iExpression;
         } else {
            throw FWExpressionException("syntax error", -1);
            //std::cout <<"failed to parse "<<iExpression<<" because of syntax error"<<std::endl;
         }
      } catch(const reco::parser::BaseException& e) {
         //NOTE: need to calculate actual position before doing the regex
         throw FWExpressionException(reco::parser::baseExceptionWhat(e), indexFromNewFormatToOldFormat(temp,e.where-temp.c_str(),iExpression));
         //std::cout <<"failed to parse "<<iExpression<<" because "<<reco::parser::baseExceptionWhat(e)<<std::endl;
      }
   } else {
      m_expression=iExpression;
   }
}

void
FWExpressionEvaluator::setClassName(const std::string& iClassName)
{
   //NOTE: How do we handle the case where the filter was created before
   // the library for the class was loaded and therefore we don't have
   // a dictionary for it?

   m_className = iClassName;
   m_type = edm::TypeWithDict::byName(iClassName);
   setExpression(m_expression);
}

//
// const member functions
//
const std::string&
FWExpressionEvaluator::expression() const
{
   return m_expression;
}

double
FWExpressionEvaluator::evalExpression(const void* iObject) const
{
   if(m_expression.empty() || !m_expr.get()) {
      return 0;
   }

   edm::ObjectWithDict o(m_type, const_cast<void *>(iObject));
   return m_expr->value(o);
}

//
// static member functions
//