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#include "lextrans.h"
#include <iostream>
#include <cstdlib>
#include "filelib.h"
#include "hg.h"
#include "tdict.h"
#include "grammar.h"
#include "sentence_metadata.h"
using namespace std;
struct LexicalTransImpl {
LexicalTransImpl(const boost::program_options::variables_map& conf) :
use_null(conf.count("lextrans_use_null") > 0),
psg_file_(),
kXCAT(TD::Convert("X")*-1),
kNULL(TD::Convert("<eps>")),
kBINARY(new TRule("[X] ||| [X,1] [X,2] ||| [1] [2]")),
kGOAL_RULE(new TRule("[Goal] ||| [X,1] ||| [1]")) {
if (conf.count("per_sentence_grammar_file")) {
psg_file_ = new ifstream(conf["per_sentence_grammar_file"].as<string>().c_str());
}
vector<string> gfiles = conf["grammar"].as<vector<string> >();
assert(gfiles.size() == 1);
ReadFile rf(gfiles.front());
TextGrammar *tg = new TextGrammar;
grammar.reset(tg);
istream* in = rf.stream();
int lc = 0;
bool flag = false;
string line;
while(*in) {
getline(*in, line);
if (!*in) continue;
++lc;
TRulePtr r(TRule::CreateRulePhrasetable(line));
tg->AddRule(r);
if (lc % 50000 == 0) { cerr << '.'; flag = true; }
if (lc % 2000000 == 0) { cerr << " [" << lc << "]\n"; flag = false; }
}
if (flag) cerr << endl;
cerr << "Loaded " << lc << " rules\n";
}
void LoadSentenceGrammar(const string& s_offset) {
const unsigned long long int offset = strtoull(s_offset.c_str(), NULL, 10);
psg_file_->seekg(offset, ios::beg);
TextGrammar *tg = new TextGrammar;
sup_grammar.reset(tg);
const string kEND_MARKER = "###EOS###";
string line;
while(true) {
assert(*psg_file_);
getline(*psg_file_, line);
if (line == kEND_MARKER) break;
TRulePtr r(TRule::CreateRulePhrasetable(line));
tg->AddRule(r);
}
}
void BuildTrellis(const Lattice& lattice, const SentenceMetadata& smeta, Hypergraph* forest) {
if (psg_file_) {
const string offset = smeta.GetSGMLValue("psg");
if (offset.size() < 2 || offset[0] != '@') {
cerr << "per_sentence_grammar_file given but sentence id=" << smeta.GetSentenceID() << " doesn't have grammar info!\n";
abort();
}
LoadSentenceGrammar(offset.substr(1));
}
const int e_len = smeta.GetTargetLength();
assert(e_len > 0);
const int f_len = lattice.size();
// hack to tell the feature function system how big the sentence pair is
const int f_start = (use_null ? -1 : 0);
int prev_node_id = -1;
for (int i = 0; i < e_len; ++i) { // for each word in the *target*
Hypergraph::Node* node = forest->AddNode(kXCAT);
const int new_node_id = node->id_;
for (int j = f_start; j < f_len; ++j) { // for each word in the source
const WordID src_sym = (j < 0 ? kNULL : lattice[j][0].label);
const GrammarIter* gi = grammar->GetRoot()->Extend(src_sym);
if (!gi) {
if (psg_file_)
gi = sup_grammar->GetRoot()->Extend(src_sym);
if (!gi) {
cerr << "No translations found for: " << TD::Convert(src_sym) << "\n";
abort();
}
}
const RuleBin* rb = gi->GetRules();
assert(rb);
for (int k = 0; k < rb->GetNumRules(); ++k) {
TRulePtr rule = rb->GetIthRule(k);
Hypergraph::Edge* edge = forest->AddEdge(rule, Hypergraph::TailNodeVector());
edge->i_ = j;
edge->j_ = j+1;
edge->prev_i_ = i;
edge->prev_j_ = i+1;
edge->feature_values_ += edge->rule_->GetFeatureValues();
forest->ConnectEdgeToHeadNode(edge->id_, new_node_id);
}
}
if (prev_node_id >= 0) {
const int comb_node_id = forest->AddNode(kXCAT)->id_;
Hypergraph::TailNodeVector tail(2, prev_node_id);
tail[1] = new_node_id;
Hypergraph::Edge* edge = forest->AddEdge(kBINARY, tail);
forest->ConnectEdgeToHeadNode(edge->id_, comb_node_id);
prev_node_id = comb_node_id;
} else {
prev_node_id = new_node_id;
}
}
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);
}
private:
const bool use_null;
ifstream* psg_file_;
const WordID kXCAT;
const WordID kNULL;
const TRulePtr kBINARY;
const TRulePtr kGOAL_RULE;
GrammarPtr grammar;
GrammarPtr sup_grammar;
};
LexicalTrans::LexicalTrans(const boost::program_options::variables_map& conf) :
pimpl_(new LexicalTransImpl(conf)) {}
bool LexicalTrans::TranslateImpl(const string& input,
SentenceMetadata* smeta,
const vector<double>& weights,
Hypergraph* forest) {
Lattice& lattice = smeta->src_lattice_;
LatticeTools::ConvertTextOrPLF(input, &lattice);
if (!lattice.IsSentence()) {
// lexical models make independence assumptions
// that don't work with lattices or conf nets
cerr << "LexicalTrans: cannot deal with lattice source input!\n";
abort();
}
smeta->SetSourceLength(lattice.size());
pimpl_->BuildTrellis(lattice, *smeta, forest);
forest->is_linear_chain_ = true;
forest->Reweight(weights);
return true;
}
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