mosesdecoder/moses/TranslationOptionCollectionText.cpp
2013-11-19 17:23:19 +00:00

194 lines
7.0 KiB
C++

// $Id$
/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2006 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
***********************************************************************/
#include "TranslationOptionCollectionText.h"
#include "Sentence.h"
#include "DecodeStep.h"
#include "DecodeStepTranslation.h"
#include "FactorCollection.h"
#include "WordsRange.h"
#include <list>
using namespace std;
namespace Moses
{
/** constructor; just initialize the base class */
TranslationOptionCollectionText::TranslationOptionCollectionText(Sentence const &input, size_t maxNoTransOptPerCoverage, float translationOptionThreshold)
: TranslationOptionCollection(input, maxNoTransOptPerCoverage, translationOptionThreshold)
{
size_t size = input.GetSize();
m_inputPathMatrix.resize(size);
for (size_t phaseSize = 1; phaseSize <= size; ++phaseSize) {
for (size_t startPos = 0; startPos < size - phaseSize + 1; ++startPos) {
size_t endPos = startPos + phaseSize -1;
vector<InputPath*> &vec = m_inputPathMatrix[startPos];
WordsRange range(startPos, endPos);
Phrase subphrase(input.GetSubString(WordsRange(startPos, endPos)));
const NonTerminalSet &labels = input.GetLabelSet(startPos, endPos);
InputPath *path;
if (range.GetNumWordsCovered() == 1) {
path = new InputPath(subphrase, labels, range, NULL, NULL);
vec.push_back(path);
} else {
const InputPath &prevPath = GetInputPath(startPos, endPos - 1);
path = new InputPath(subphrase, labels, range, &prevPath, NULL);
vec.push_back(path);
}
m_inputPathQueue.push_back(path);
}
}
}
/* forcibly create translation option for a particular source word.
* For text, this function is easy, just call the base class' ProcessOneUnknownWord()
*/
void TranslationOptionCollectionText::ProcessUnknownWord(size_t sourcePos)
{
const InputPath &inputPath = GetInputPath(sourcePos, sourcePos);
ProcessOneUnknownWord(inputPath,sourcePos);
}
/**
* Check the source sentence for coverage data
*/
bool TranslationOptionCollectionText::HasXmlOptionsOverlappingRange(size_t startPosition, size_t endPosition) const
{
Sentence const& source=dynamic_cast<Sentence const&>(m_source);
return source.XmlOverlap(startPosition,endPosition);
}
/**
* Check if the given translation option violates a specified xml Option
*/
bool TranslationOptionCollectionText::ViolatesXmlOptionsConstraint(size_t startPosition, size_t endPosition, TranslationOption *transOpt) const
{
// skip if there is no overlap
Sentence const& source=dynamic_cast<Sentence const&>(m_source);
if (!source.XmlOverlap(startPosition,endPosition)) {
return false;
}
vector <TranslationOption*> xmlOptions;
source.GetXmlTranslationOptions(xmlOptions);
for(size_t i=0; i<xmlOptions.size(); i++) {
const WordsRange &range = xmlOptions[i]->GetSourceWordsRange();
// if transOpt is a subphrase of a xml specification, do not use it
if (range.GetStartPos() <= startPosition && range.GetEndPos() >= endPosition &&
(range.GetStartPos() < startPosition || range.GetEndPos() > endPosition)) {
return true;
}
// if transOpt is partially overlapping, do not use it
if ((range.GetStartPos() < startPosition && range.GetEndPos() >= startPosition && range.GetEndPos() < endPosition) ||
(range.GetEndPos() > endPosition && range.GetStartPos() <= endPosition && range.GetStartPos() > startPosition)) {
return true;
}
// if transOpt is match or superphrase, check
if (range.GetStartPos() >= startPosition && range.GetEndPos() <= endPosition) {
const TargetPhrase &phrase = transOpt->GetTargetPhrase();
const TargetPhrase &xmlPhrase = xmlOptions[i]->GetTargetPhrase();
// if transOpt target is shorter, do not use it
if (phrase.GetSize() < xmlPhrase.GetSize()) {
return true;
}
// match may start in middle of phrase
for(size_t offset=0; offset <= phrase.GetSize()-xmlPhrase.GetSize(); offset++) {
bool match = true;
// match every word (only surface factor)
for(size_t wordPos=0; match && wordPos < xmlPhrase.GetSize(); wordPos++) {
if (phrase.GetFactor( wordPos+offset,0 )->Compare(*(xmlPhrase.GetFactor( wordPos,0 )))) {
match = false;
}
}
if (match) {
return false; // no violation if matching xml option found
}
}
return true;
}
}
return false;
}
/**
* Create xml-based translation options for the specific input span
*/
void TranslationOptionCollectionText::CreateXmlOptionsForRange(size_t startPos, size_t endPos)
{
Sentence const& source=dynamic_cast<Sentence const&>(m_source);
InputPath &inputPath = GetInputPath(startPos,endPos);
vector <TranslationOption*> xmlOptions;
source.GetXmlTranslationOptions(xmlOptions,startPos,endPos);
//get vector of TranslationOptions from Sentence
for(size_t i=0; i<xmlOptions.size(); i++) {
TranslationOption *transOpt = xmlOptions[i];
transOpt->SetInputPath(inputPath);
Add(transOpt);
}
};
InputPath &TranslationOptionCollectionText::GetInputPath(size_t startPos, size_t endPos)
{
size_t offset = endPos - startPos;
assert(offset < m_inputPathMatrix[startPos].size());
return *m_inputPathMatrix[startPos][offset];
}
void TranslationOptionCollectionText::CreateTranslationOptions()
{
GetTargetPhraseCollectionBatch();
TranslationOptionCollection::CreateTranslationOptions();
}
/** create translation options that exactly cover a specific input span.
* Called by CreateTranslationOptions() and ProcessUnknownWord()
* \param decodeGraph list of decoding steps
* \param factorCollection input sentence with all factors
* \param startPos first position in input sentence
* \param lastPos last position in input sentence
* \param adhereTableLimit whether phrase & generation table limits are adhered to
*/
void TranslationOptionCollectionText::CreateTranslationOptionsForRange(
const DecodeGraph &decodeGraph
, size_t startPos
, size_t endPos
, bool adhereTableLimit
, size_t graphInd)
{
InputPath &inputPath = GetInputPath(startPos, endPos);
TranslationOptionCollection::CreateTranslationOptionsForRange(decodeGraph
, startPos
, endPos
, adhereTableLimit
, graphInd
, inputPath);
}
}