source: trunk/lib/Functor.h @ 485

#ifndef _theplu_svndigest_functor_
#define _theplu_svndigest_functor_

// $Id: Functor.h 485 2007-10-13 20:13:54Z peter $

/*
  Copyright (C) 2005, 2006, 2007 Jari Häkkinen, Peter Johansson

  This file is part of svndigest, http://trac.thep.lu.se/trac/svndigest

  svndigest is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  svndigest 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
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

//#include <algorithm>
#include <functional>
//#include <iosfwd>
#include <string>
#include <utility>
#include <vector>

#include <sys/stat.h>

namespace theplu{
namespace svndigest{

  struct AlNum
  {
    inline bool operator()(std::string::const_iterator i) const 
    { return isalnum(*i); }
  };


  struct Digit
  {
    inline bool operator()(std::string::const_iterator i) const 
    { return isdigit(*i); }
  };


  class notChar
  {
  public:
    notChar(char);
    inline bool operator()(std::string::const_iterator i) const 
    { return *i!=char_; }
  private:
    char char_;
  };


  class not2Char
  {
  public:
    not2Char(char, char);
    inline bool operator()(std::string::const_iterator i) const 
    { return *i!=char1_ && *i!=char2_; }
  private:
    const char char1_;
    const char char2_;
  };

  class not2Str
  {
  public:
    not2Str(std::string, std::string);
    inline bool operator()(std::string::const_iterator i) const 
    { 
      return !(std::equal(str1_.begin(), str1_.end(), i) ||
              std::equal(str2_.begin(), str2_.end(), i));
    } 

  private:
    const std::string str1_;
    const std::string str2_;
  };

  ///
  /// Functor to be used on contaioners and works as standard less,
  /// but on the reversed container.
  ///
  /// Requirements on T is that has rend and rbegin. T::value_type
  /// must be comparable (i.e. have operator<)
  /// 
  template <typename T>
  struct LessReversed
  {
    ///
    /// using std::lexicographical_compare on the reversed container
    ///
    inline bool operator()(const T& x, const T& y) const
    { return std::lexicographical_compare(x.rbegin(),x.rend(),
                                          y.rbegin(),y.rend()); }
  };


  ///
  /// @brief Functor comparing pairs using second.
  ///
  /// STL provides operator< for the pair.first element, but none for
  /// pair.second. This template provides this and can be used as the
  /// comparison object in generic functions such as the STL sort.
  ///
  template <typename T1, typename T2>
  struct pair_value_compare
  {
    ///
    /// @return true if x.second<y.second or (x.second==y.second and
    /// x.first<y.first)
    ///
    inline bool operator()(const std::pair<T1,T2>& x,
                           const std::pair<T1,T2>& y) {
      return ((x.second<y.second) ||
              (!(y.second<x.second) && (x.first<y.first))); 
    }
  };

  
  ///
  /// Functor working on pair.second, using a user passed functor.
  ///
  template <typename T1, typename T2, typename T3>
  struct PairSecondCompare
  {

    ///
    /// @brief Constructor
    ///
    explicit PairSecondCompare(const T3& comp)
      : compare_(comp) {}

    ///
    /// @return compare(x.second, y.second) where compare is a
    /// internal comparison functor.
    ///
    inline bool operator()(const std::pair<T1,T2>& x,
                           const std::pair<T1,T2>& y) const
    { return compare_(x.second,y.second); }

  private:
    T3 compare_;

  };
  
  ///
  /// Calculating sum of two vectors.
  ///
  /// @return resulting vector
  ///
  template <typename T >
  struct VectorPlus : 
    public std::binary_function<std::vector<T>,std::vector<T>,std::vector<T> >
  {
    std::vector<T> operator()(const std::vector<T>& u,
                              const std::vector<T>& v) const 
    {
      std::vector<T> res;
      res.reserve(std::max(u.size(), v.size()));
      std::back_insert_iterator<std::vector<T> > inserter(res);
      if ( u.size() > v.size() ){
        std::transform(v.begin(), v.end(), u.begin(), inserter, std::plus<T>());
        std::copy(u.begin()+v.size(), u.end(), inserter);
      }
      else {
        std::transform(u.begin(), u.end(), v.begin(), inserter, std::plus<T>());
        std::copy(v.begin()+u.size(), v.end(), inserter);
      }
      return res;
    }

  };

  ///
  /// @return resulting vector
  ///
  template <typename Key, typename T>
  struct PairValuePlus :
    public std::binary_function<std::vector<T>,
                                std::pair<const Key, std::vector<T> >, 
                                std::vector<T> >
  {
    std::vector<T> operator()(const std::vector<T>& sum, 
                              const std::pair<const Key,std::vector<T> >& p)
    {
      return VectorPlus<T>()(sum, p.second);
    }
  };

}} // end of namespace svndigest end of namespace theplu

#endif