lyx_mirror/src/support/translator.h
André Pönitz 6c300f72a2 move everything into namespace lyx
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@15422 a592a061-630c-0410-9148-cb99ea01b6c8
2006-10-21 00:16:43 +00:00

121 lines
2.7 KiB
C++

// -*- C++ -*-
/**
* \file translator.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Baruch Even
*
* Full author contact details are available in file CREDITS.
*/
#ifndef TRANSLATOR_H
#define TRANSLATOR_H
#include <boost/assert.hpp>
#include <boost/bind.hpp>
#include <vector>
#include <utility>
#include <algorithm>
#include <functional>
namespace lyx {
/**
* This class template is used to translate between two elements, specifically
* it was worked out to translate between an enum and strings when reading
* the lyx file.
*
* The two template arguments should be of different types.
*/
template<typename T1, typename T2>
class Translator {
public:
///
typedef T1 first_argument_type;
///
typedef T2 second_argument_type;
///
typedef std::pair<T1, T2> MapPair;
///
typedef std::vector<MapPair> Map;
///
Translator(T1 const & t1, T2 const & t2)
: default_t1(t1), default_t2(t2)
{}
/// Add a mapping to the translator.
void addPair(T1 const & first, T2 const & second) {
map.push_back(MapPair(first, second));
}
// Add the contents of \c other
void add(Translator const & other) {
if (other.map.empty())
return;
map.insert(map.end(), other.map.begin(), other.map.end());
}
/// Find the mapping for the first argument
T2 const & find(T1 const & first) const {
BOOST_ASSERT(!map.empty());
// For explanation see the next find() function.
typename Map::const_iterator it =
std::find_if(map.begin(), map.end(),
boost::bind(std::equal_to<T1>(),
boost::bind(&MapPair::first, _1),
first)
);
if (it != map.end()) {
return it->second;
} else {
return default_t2;
}
}
/// Find the mapping for the second argument
T1 const & find(T2 const & second) const {
BOOST_ASSERT(!map.empty());
// The idea is as follows:
// find_if() will try to compare the data in the vector with
// the value. The vector is made of pairs and the value has
// the type of the second part of the pair.
// We thus give find_if() an equal_to functor and assign to
// its second post the value we want to compare. We now
// compose the equal_to functor with the select2nd functor
// to take only the second value of the pair to be compared.
//
// We can depict it as follows:
// equal_to(select2nd(pair) , second)
typename Map::const_iterator it =
std::find_if(map.begin(), map.end(),
boost::bind(std::equal_to<T2>(),
boost::bind(&MapPair::second, _1),
second)
);
if (it != map.end())
return it->first;
else {
return default_t1;
}
}
private:
///
Map map;
///
T1 const default_t1;
///
T2 const default_t2;
};
} // namespace lyx
#endif // TRANSLATOR_H