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#include "translator.h"
#include <sstream>
#include <boost/shared_ptr.hpp>
#include "sentence_metadata.h"
#include "filelib.h"
#include "hg.h"
#include "hg_io.h"
#include "earley_composer.h"
#include "phrasetable_fst.h"
#include "tdict.h"
using namespace std;
struct FSTTranslatorImpl {
FSTTranslatorImpl(const boost::program_options::variables_map& conf) :
goal_sym(conf["goal"].as<string>()),
kGOAL_RULE(new TRule("[Goal] ||| [" + goal_sym + ",1] ||| [1]")),
kGOAL(TD::Convert("Goal") * -1),
add_pass_through_rules(conf.count("add_pass_through_rules")) {
fst.reset(LoadTextPhrasetable(conf["grammar"].as<vector<string> >()));
ec.reset(new EarleyComposer(fst.get()));
}
bool Translate(const string& input,
const vector<double>& weights,
Hypergraph* forest) {
bool composed = false;
if (input.find("{\"rules\"") == 0) {
istringstream is(input);
Hypergraph src_cfg_hg;
if (!HypergraphIO::ReadFromJSON(&is, &src_cfg_hg)) {
cerr << "Failed to read HG from JSON.\n";
abort();
}
if (add_pass_through_rules) {
SparseVector<double> feats;
feats.set_value(FD::Convert("PassThrough"), 1);
for (int i = 0; i < src_cfg_hg.edges_.size(); ++i) {
const vector<WordID>& f = src_cfg_hg.edges_[i].rule_->f_;
for (int j = 0; j < f.size(); ++j) {
if (f[j] > 0) {
fst->AddPassThroughTranslation(f[j], feats);
}
}
}
}
composed = ec->Compose(src_cfg_hg, forest);
} else {
const string dummy_grammar("[" + goal_sym + "] ||| " + input + " ||| TOP=1");
cerr << " Dummy grammar: " << dummy_grammar << endl;
istringstream is(dummy_grammar);
if (add_pass_through_rules) {
vector<WordID> words;
TD::ConvertSentence(input, &words);
SparseVector<double> feats;
feats.set_value(FD::Convert("PassThrough"), 1);
for (int i = 0; i < words.size(); ++i)
fst->AddPassThroughTranslation(words[i], feats);
}
composed = ec->Compose(&is, forest);
}
if (composed) {
Hypergraph::TailNodeVector tail(1, forest->nodes_.size() - 1);
Hypergraph::Node* goal = forest->AddNode(TD::Convert("Goal")*-1);
Hypergraph::Edge* hg_edge = forest->AddEdge(kGOAL_RULE, tail);
forest->ConnectEdgeToHeadNode(hg_edge, goal);
forest->Reweight(weights);
}
if (add_pass_through_rules)
fst->ClearPassThroughTranslations();
return composed;
}
const string goal_sym;
const TRulePtr kGOAL_RULE;
const WordID kGOAL;
const bool add_pass_through_rules;
boost::shared_ptr<EarleyComposer> ec;
boost::shared_ptr<FSTNode> fst;
};
FSTTranslator::FSTTranslator(const boost::program_options::variables_map& conf) :
pimpl_(new FSTTranslatorImpl(conf)) {}
bool FSTTranslator::TranslateImpl(const string& input,
SentenceMetadata* smeta,
const vector<double>& weights,
Hypergraph* minus_lm_forest) {
smeta->SetSourceLength(0); // don't know how to compute this
return pimpl_->Translate(input, weights, minus_lm_forest);
}
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