eoHowMany.h

// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-

//-----------------------------------------------------------------------------
// eoHowMany_h.h
//   Base class for choosing a number of guys to apply something from a popsize
// (c) Marc Schoenauer, 2000
/*
   This library 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 (at your option) any later version.

   This library 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 this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

   Contact: todos@geneura.ugr.es, http://geneura.ugr.es
 */
//-----------------------------------------------------------------------------

#ifndef eoHowMany_h
#define eoHowMany_h

#include <sstream>

class eoHowMany : public eoPersistent
{
public:
  eoHowMany(double  _rate = 0.0, bool _interpret_as_rate = true):
    rate(_rate), combien(0)
  {
    if (_interpret_as_rate)
      {
        if (_rate<0)
          {
            rate = 1.0+_rate;
            if (rate < 0)          // was < -1
              throw std::logic_error("rate<-1 in eoHowMany!");
          }
      }
    else
      {
        rate = 0.0;                // just in case, but shoud be unused
        combien = int(_rate);      // negative values are allowed here
        if (combien != _rate)
          std::cerr << "Warning: Number was rounded in eoHowMany";
      }
  }

  eoHowMany(int _combien) : rate(0.0), combien(_combien) {}

  eoHowMany(unsigned int _combien) : rate(0.0), combien(_combien) {}

  virtual ~eoHowMany() {}

  unsigned int operator()(unsigned int _size)
  {
    if (combien == 0)
      {
        return (unsigned int) (rate * _size);
      }
    if (combien < 0)
      {
        unsigned int combloc = -combien;
        if (_size<combloc)
          throw std::runtime_error("Negative result in eoHowMany");
        return _size-combloc;
      }
    return unsigned(combien);
  }

  virtual void printOn(std::ostream& _os) const
  {
    if (combien == 0)
      _os << 100*rate << "% ";
    else
      _os << combien << " ";
    return;

  }

  virtual void readFrom(std::istream& _is)
   {
    std::string value;
    _is >> value;
    readFrom(value);
    return;
  }

  void readFrom(std::string _value)
  {
    // check for %
    bool interpret_as_rate = false;   // == no %
    size_t pos =  _value.find('%');
    if (pos < _value.size())  //  found a %
      {
        interpret_as_rate = true;
        _value.resize(pos);        // get rid of %
      }

    std::istringstream is(_value);
    is >> rate;
    // now store
    if (interpret_as_rate)
      {
        combien = 0;
        rate /= 100.0;
      }
    else
      combien = int(rate);         // and rate will not be used

    // minimal check
    if ( rate < 0.0 )
      throw std::runtime_error("Negative rate read in eoHowMany::readFrom");
  }

  eoHowMany operator-()
  {
    if (!combien)                  // only rate is used
      rate = 1.0-rate;
    else
      combien = -combien;
    return (*this);
  }

private :
  double rate;
  int combien;
};



#endif

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