1 files changed, 58 insertions, 0 deletions
diff --git a/decoder/rescore_translator.cc b/decoder/rescore_translator.cc
new file mode 100644
index 00000000..10192f7a
--- /dev/null
+++ b/decoder/rescore_translator.cc
@@ -0,0 +1,58 @@
+#include "translator.h"
+
+#include <sstream>
+#include <boost/shared_ptr.hpp>
+
+#include "sentence_metadata.h"
+#include "hg.h"
+#include "hg_io.h"
+#include "tdict.h"
+
+using namespace std;
+
+struct RescoreTranslatorImpl {
+  RescoreTranslatorImpl(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) {
+  }
+
+  bool Translate(const string& input,
+                 const vector<double>& weights,
+                 Hypergraph* forest) {
+    if (input == "{}") return false;
+    if (input.find("{\"rules\"") == 0) {
+      istringstream is(input);
+      Hypergraph src_cfg_hg;
+      if (!HypergraphIO::ReadFromJSON(&is, forest)) {
+        cerr << "Parse error while reading HG from JSON.\n";
+        abort();
+      }
+    } else {
+      cerr << "Can only read HG input from JSON: use training/grammar_convert\n";
+      abort();
+    }
+    Hypergraph::TailNodeVector tail(1, forest->nodes_.size() - 1);
+    Hypergraph::Node* goal = forest->AddNode(kGOAL);
+    Hypergraph::Edge* hg_edge = forest->AddEdge(kGOAL_RULE, tail);
+    forest->ConnectEdgeToHeadNode(hg_edge, goal);
+    forest->Reweight(weights);
+    return true;
+  }
+
+  const string goal_sym;
+  const TRulePtr kGOAL_RULE;
+  const WordID kGOAL;
+};
+
+RescoreTranslator::RescoreTranslator(const boost::program_options::variables_map& conf) :
+  pimpl_(new RescoreTranslatorImpl(conf)) {}
+
+bool RescoreTranslator::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);
+}
+