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/***********************************************************************
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
***********************************************************************/
#include "Parser.h"
#include "moses/ChartParser.h"
#include "moses/ChartTranslationOptionList.h"
#include "moses/InputType.h"
#include "moses/NonTerminal.h"
#include "moses/TranslationModel/RuleTable/UTrieNode.h"
#include "moses/TranslationModel/RuleTable/UTrie.h"
#include "moses/StaticData.h"
#include "ApplicableRuleTrie.h"
#include "StackLattice.h"
#include "StackLatticeBuilder.h"
#include "StackLatticeSearcher.h"
#include "VarSpanTrieBuilder.h"
#include <memory>
#include <vector>
namespace Moses
{
void Scope3Parser::GetChartRuleCollection(
const InputPath &inputPath,
size_t last,
ChartParserCallback &outColl)
{
const Range &range = inputPath.GetWordsRange();
const size_t start = range.GetStartPos();
const size_t end = range.GetEndPos();
std::vector<std::pair<const UTrieNode *, const VarSpanNode *> > &pairVec
= m_ruleApplications[start][end-start+1];
MatchCallback matchCB(range, outColl);
for (std::vector<std::pair<const UTrieNode *, const VarSpanNode *> >::const_iterator p = pairVec.begin(); p != pairVec.end(); ++p) {
const UTrieNode &ruleNode = *(p->first);
const VarSpanNode &varSpanNode = *(p->second);
const UTrieNode::LabelMap &labelMap = ruleNode.GetLabelMap();
if (varSpanNode.m_rank == 0) { // Purely lexical rule.
assert(labelMap.size() == 1);
TargetPhraseCollection::shared_ptr tpc = labelMap.begin()->second;
matchCB.m_tpc = tpc;
matchCB(m_emptyStackVec);
} else { // Rule has at least one non-terminal.
varSpanNode.CalculateRanges(start, end, m_ranges);
m_latticeBuilder.Build(start, end, ruleNode, varSpanNode, m_ranges,
*this, m_lattice,
m_quickCheckTable);
StackLatticeSearcher<MatchCallback> searcher(m_lattice, m_ranges);
UTrieNode::LabelMap::const_iterator p = labelMap.begin();
for (; p != labelMap.end(); ++p) {
const std::vector<int> &labels = p->first;
TargetPhraseCollection::shared_ptr tpc = p->second;
assert(labels.size() == varSpanNode.m_rank);
bool failCheck = false;
for (size_t i = 0; i < varSpanNode.m_rank; ++i) {
if (!m_quickCheckTable[i][labels[i]]) {
failCheck = true;
break;
}
}
if (failCheck) {
continue;
}
matchCB.m_tpc = tpc;
searcher.Search(labels, matchCB);
}
}
}
}
void Scope3Parser::Init()
{
InitRuleApplicationVector();
// Build a map from Words to index-sets.
SentenceMap sentMap;
FillSentenceMap(sentMap);
// Build a trie containing 'elastic' application contexts
const UTrieNode &rootNode = m_ruleTable.GetRootNode();
std::auto_ptr<ApplicableRuleTrie> art(new ApplicableRuleTrie(-1, -1, rootNode));
art->Extend(rootNode, -1, sentMap, false);
// Build a trie containing just the non-terminal contexts and insert pointers
// to its nodes back into the ART trie. Contiguous non-terminal contexts are
// merged and the number of split points is recorded.
VarSpanTrieBuilder vstBuilder;
m_varSpanTrie = vstBuilder.Build(*art);
// Fill each cell with a list of pointers to relevant ART nodes.
AddRulesToCells(*art, std::make_pair<int, int>(-1, -1), GetParser().GetSize()-1, 0);
}
void Scope3Parser::InitRuleApplicationVector()
{
const size_t sourceSize = GetParser().GetSize();
m_ruleApplications.resize(sourceSize);
for (size_t start = 0; start < sourceSize; ++start) {
size_t maxSpan = sourceSize-start+1;
m_ruleApplications[start].resize(maxSpan+1);
}
}
void Scope3Parser::FillSentenceMap(SentenceMap &sentMap)
{
for (size_t i = 0; i < GetParser().GetSize(); ++i) {
const Word &word = GetParser().GetInputPath(i, i).GetLastWord();
sentMap[word].push_back(i);
}
}
void Scope3Parser::AddRulesToCells(
const ApplicableRuleTrie &node,
std::pair<int, int> start,
int maxPos,
int depth)
{
if (depth > 0) {
// Determine the start range for this path if not already known.
if (start.first == -1 && start.second == -1) {
assert(depth == 1);
start.first = std::max(0, node.m_start);
start.second = node.m_start;
} else if (start.second < 0) {
assert(depth > 1);
if (node.m_start == -1) {
--start.second; // Record split point
} else {
int numSplitPoints = -1 - start.second;
start.second = node.m_start - (numSplitPoints+1);
}
}
}
if (node.m_node->HasRules()) {
assert(depth > 0);
assert(node.m_vstNode);
// Determine the end range for this path.
std::pair<int, int> end;
if (node.m_end == -1) {
end.first = (*(node.m_vstNode->m_label))[2];
end.second = (*(node.m_vstNode->m_label))[3];
assert(end.first != -1);
if (end.second == -1) {
end.second = maxPos;
}
} else {
assert(node.m_start == node.m_end); // Should be a terminal
end.first = end.second = node.m_start;
}
// Add a (rule trie node, VST node) pair for each cell in the range.
int s2 = start.second;
if (s2 < 0) {
int numSplitPoints = -1 - s2;
s2 = maxPos - numSplitPoints;
}
for (int i = start.first; i <= s2; ++i) {
int e1 = std::max(i+depth-1, end.first);
for (int j = e1; j <= end.second; ++j) {
size_t span = j-i+1;
assert(span >= 1);
if (m_maxChartSpan && span > m_maxChartSpan) {
break;
}
m_ruleApplications[i][span].push_back(std::make_pair(node.m_node,
node.m_vstNode));
}
}
}
for (std::vector<ApplicableRuleTrie*>::const_iterator p = node.m_children.begin(); p != node.m_children.end(); ++p) {
AddRulesToCells(**p, start, maxPos, depth+1);
}
}
} // namespace Moses
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