source: trunk/yat/utility/utility.h @ 1789

#ifndef _theplu_yat_utility_utility_
#define _theplu_yat_utility_utility_ 

// $Id: utility.h 1789 2009-02-10 16:11:04Z peter $

/*
  Copyright (C) 2005 Jari Häkkinen, Peter Johansson, Markus Ringnér
  Copyright (C) 2006 Jari Häkkinen
  Copyright (C) 2007 Jari Häkkinen, Peter Johansson
  Copyright (C) 2008 Peter Johansson

  This file is part of the yat library, http://dev.thep.lu.se/yat

  The yat library 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 3 of the
  License, or (at your option) any later version.

  The yat 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
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with yat. If not, see <http://www.gnu.org/licenses/>.
*/

///
/// \file yat/utility/utility.h
///
/// @brief Some useful functions are placed here
///

#include "deprecate.h"

#include <cmath>
#include <limits>
#include <string>
#include <stdexcept>
#include <sstream>
#include <utility>
#include <vector>

namespace theplu {
namespace yat {
namespace utility {

  /**
     For each element in resulting range assign it to 0.0 if
     corresponding element in input range is NaN else assign it to
     1.0.

     \since New in yat 0.5
   */
  struct BinaryWeight
  {
    /** 
        \return true if there is at least one NaN in input range
        [first, last).
     */
    template<typename InputIterator, typename OutputIterator>
    bool operator()(InputIterator first, InputIterator last, 
                    OutputIterator result) const;
  };


  /**
     \brief convert string to (numerical) type

     \throw runtime_error if conversion fails
   */
  template<typename T>
  T convert(const std::string& s);

  /**
     \brief check if string is convertible to (numerical) type

     \since New in yat 0.5
   */
  template<typename T>
  bool is(const std::string& s);

  ///
  /// @return true if string is a double
  ///
  /// \deprecated Provided for backward compatibility with the 0.4
  /// API. Use is<double>(const std::string&)
  ///
  bool is_double(const std::string&) YAT_DEPRECATE;

  /**
     @return true if string \a s fulfills regular expression \verbatim
     ^\w* \endverbatim \a other \verbatim \w*$ \endverbatim (case
     insensitive)
  */
  bool is_equal(std::string s, std::string other);

  ///
  /// @return true if string is a float
  ///
  /// \deprecated Provided for backward compatibility with the 0.4
  /// API. Use is<float>(const std::string&)
  ///
  bool is_float(const std::string&) YAT_DEPRECATE;

  ///
  /// @return true if string is an int
  ///
  /// \deprecated Provided for backward compatibility with the 0.4
  /// API. Use is<int>(const std::string&)
  ///
  bool is_int(const std::string&) YAT_DEPRECATE;

  ///
  /// @return true if string is "nan" (case-insensitive) 
  ///
  bool is_nan(const std::string& s);


  template<typename InputIterator, typename OutputIterator>
  bool BinaryWeight::operator()(InputIterator first, InputIterator last, 
                                OutputIterator result) const
  {
    bool nan=false;
    while (first!=last) {
      if (std::isnan(*first)) {
        *result=0;
        nan=true;
      }
      else
        *result = 1.0;
      ++first;
      ++result;
    }
    return nan;
  }


  // template implementations
  template<typename T>
  T convert(const std::string& s)
  {
    if (is_nan(s))
      return std::numeric_limits<T>::quiet_NaN();
    if (is_equal(s, "inf"))
      return std::numeric_limits<T>::infinity();
    if (is_equal(s, "-inf"))
      if (std::numeric_limits<T>::is_signed)
        return -std::numeric_limits<T>::infinity();
      else
        throw std::runtime_error(std::string("convert(\"")+s+
                                 std::string("\"): type is unsigned") );
    std::stringstream ss(s);
    T a;
    ss >> a;
    bool ok = true;
    if(ss.fail()) 
      ok = false;
    // Check that nothing is left on stream
    std::string b;
    ss >> b;
    if (!b.empty() || !ok)
      throw std::runtime_error(std::string("convert(\"")+s+std::string("\")"));
    return a;
  }

  template<typename T>
  bool is(const std::string& s)
  {
    if (is_nan(s))
      return std::numeric_limits<T>::has_quiet_NaN;
    if (is_equal(s, "inf"))
      return std::numeric_limits<T>::has_infinity;
    if (is_equal(s, "-inf"))
      return std::numeric_limits<T>::has_infinity && 
        std::numeric_limits<T>::is_signed;
    std::stringstream ss(s);
    T a;
    ss >> a;
    if(ss.fail())
      return false;
    // Check that nothing is left on stream
    std::string b;
    ss >> b;
    return b.empty();
  }

}}} // of namespace utility, yat, and theplu

#endif