mosesdecoder/moses/Terminal.h

68 lines
2.0 KiB
C++

/***********************************************************************
Moses - statistical machine translation system
Copyright (C) 2006-2012 University of Edinburgh
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 2.1 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
***********************************************************************/
#pragma once
#include "TypeDef.h"
#include "Word.h"
#include "Factor.h"
#include <boost/functional/hash.hpp>
namespace Moses
{
class TerminalHasher
{
public:
// Generate a hash value for a word representing a terminal. It's
// assumed that the same subset of factors will be active for all words
// that are hashed.
size_t operator()(const Word &t) const {
size_t seed = 0;
for (size_t i = 0; i < MAX_NUM_FACTORS; ++i) {
const Factor *f = t[i];
if (f) {
boost::hash_combine(seed, *f);
}
}
return seed;
}
};
class TerminalEqualityPred
{
public:
// Equality predicate for comparing words representing terminals. As
// with the hasher, it's assumed that all words will have the same
// subset of active factors.
bool operator()(const Word &t1, const Word &t2) const {
for (size_t i = 0; i < MAX_NUM_FACTORS; ++i) {
const Factor *f1 = t1[i];
const Factor *f2 = t2[i];
if (f1 && f1->Compare(*f2)) {
return false;
}
}
return true;
}
};
} // namespace Moses