1 files changed, 189 insertions, 0 deletions
diff --git a/contrib/moses2/FF/Distortion.cpp b/contrib/moses2/FF/Distortion.cpp
new file mode 100644
index 000000000..4220b731f
--- /dev/null
+++ b/contrib/moses2/FF/Distortion.cpp
@@ -0,0 +1,189 @@
+/*
+ * Distortion.cpp
+ *
+ *  Created on: 28 Oct 2015
+ *      Author: hieu
+ */
+#include <sstream>
+#include "Distortion.h"
+#include "../PhraseBased/Hypothesis.h"
+#include "../PhraseBased/Manager.h"
+#include "../legacy/Range.h"
+#include "../legacy/Bitmap.h"
+
+using namespace std;
+
+namespace Moses2
+{
+
+struct DistortionState_traditional: public FFState
+{
+  Range range;
+  int first_gap;
+
+  DistortionState_traditional() :
+      range()
+  {
+    // uninitialised
+  }
+
+  void Set(const Range& wr, int fg)
+  {
+    range = wr;
+    first_gap = fg;
+  }
+
+  size_t hash() const
+  {
+    return range.GetEndPos();
+  }
+  virtual bool operator==(const FFState& other) const
+  {
+    const DistortionState_traditional& o =
+        static_cast<const DistortionState_traditional&>(other);
+    return range.GetEndPos() == o.range.GetEndPos();
+  }
+
+  virtual std::string ToString() const
+  {
+    stringstream sb;
+    sb << first_gap << " " << range;
+    return sb.str();
+  }
+
+};
+
+///////////////////////////////////////////////////////////////////////
+Distortion::Distortion(size_t startInd, const std::string &line) :
+    StatefulFeatureFunction(startInd, line)
+{
+  ReadParameters();
+}
+
+Distortion::~Distortion()
+{
+  // TODO Auto-generated destructor stub
+}
+
+FFState* Distortion::BlankState(MemPool &pool, const System &sys) const
+{
+  return new (pool.Allocate<DistortionState_traditional>()) DistortionState_traditional();
+}
+
+void Distortion::EmptyHypothesisState(FFState &state, const ManagerBase &mgr,
+    const InputType &input, const Hypothesis &hypo) const
+{
+  DistortionState_traditional &stateCast =
+      static_cast<DistortionState_traditional&>(state);
+
+  // fake previous translated phrase start and end
+  size_t start = NOT_FOUND;
+  size_t end = NOT_FOUND;
+  /*
+   if (input.m_frontSpanCoveredLength > 0) {
+   // can happen with --continue-partial-translation
+   start = 0;
+   end = input.m_frontSpanCoveredLength -1;
+   }
+   */
+
+  stateCast.range = Range(start, end);
+  stateCast.first_gap = NOT_FOUND;
+}
+
+void Distortion::EvaluateInIsolation(MemPool &pool, const System &system,
+    const Phrase<Moses2::Word> &source, const TargetPhraseImpl &targetPhrase, Scores &scores,
+    SCORE &estimatedScore) const
+{
+}
+
+void Distortion::EvaluateInIsolation(MemPool &pool, const System &system, const Phrase<SCFG::Word> &source,
+    const TargetPhrase<SCFG::Word> &targetPhrase, Scores &scores,
+    SCORE &estimatedScore) const
+{
+}
+
+void Distortion::EvaluateWhenApplied(const ManagerBase &mgr,
+    const Hypothesis &hypo, const FFState &prevState, Scores &scores,
+    FFState &state) const
+{
+  const DistortionState_traditional &prev =
+      static_cast<const DistortionState_traditional&>(prevState);
+  SCORE distortionScore = CalculateDistortionScore(prev.range,
+      hypo.GetInputPath().range, prev.first_gap);
+  //cerr << "distortionScore=" << distortionScore << endl;
+
+  scores.PlusEquals(mgr.system, *this, distortionScore);
+
+  DistortionState_traditional &stateCast =
+      static_cast<DistortionState_traditional&>(state);
+  stateCast.Set(hypo.GetInputPath().range, hypo.GetBitmap().GetFirstGapPos());
+}
+
+SCORE Distortion::CalculateDistortionScore(const Range &prev, const Range &curr,
+    const int FirstGap) const
+{
+  bool useEarlyDistortionCost = false;
+  if (!useEarlyDistortionCost) {
+    return -(SCORE) ComputeDistortionDistance(prev, curr);
+  }
+  else {
+    /* Pay distortion score as soon as possible, from Moore and Quirk MT Summit 2007
+     Definitions:
+     S   : current source range
+     S'  : last translated source phrase range
+     S'' : longest fully-translated initial segment
+     */
+
+    int prefixEndPos = (int) FirstGap - 1;
+    if ((int) FirstGap == -1) prefixEndPos = -1;
+
+    // case1: S is adjacent to S'' => return 0
+    if ((int) curr.GetStartPos() == prefixEndPos + 1) {
+      //IFVERBOSE(4) std::cerr<< "MQ07disto:case1" << std::endl;
+      return 0;
+    }
+
+    // case2: S is to the left of S' => return 2(length(S))
+    if ((int) curr.GetEndPos() < (int) prev.GetEndPos()) {
+      //IFVERBOSE(4) std::cerr<< "MQ07disto:case2" << std::endl;
+      return (float) -2 * (int) curr.GetNumWordsCovered();
+    }
+
+    // case3: S' is a subsequence of S'' => return 2(nbWordBetween(S,S'')+length(S))
+    if ((int) prev.GetEndPos() <= prefixEndPos) {
+      //IFVERBOSE(4) std::cerr<< "MQ07disto:case3" << std::endl;
+      int z = (int) curr.GetStartPos() - prefixEndPos - 1;
+      return (float) -2 * (z + (int) curr.GetNumWordsCovered());
+    }
+
+    // case4: otherwise => return 2(nbWordBetween(S,S')+length(S))
+    //IFVERBOSE(4) std::cerr<< "MQ07disto:case4" << std::endl;
+    return (float) -2
+        * ((int) curr.GetNumWordsBetween(prev) + (int) curr.GetNumWordsCovered());
+
+  }
+}
+
+int Distortion::ComputeDistortionDistance(const Range& prev,
+    const Range& current) const
+{
+  int dist = 0;
+  if (prev.GetNumWordsCovered() == 0) {
+    dist = current.GetStartPos();
+  }
+  else {
+    dist = (int) prev.GetEndPos() - (int) current.GetStartPos() + 1;
+  }
+  return abs(dist);
+}
+
+void Distortion::EvaluateWhenApplied(const SCFG::Manager &mgr,
+    const SCFG::Hypothesis &hypo, int featureID, Scores &scores,
+    FFState &state) const
+{
+  UTIL_THROW2("Not implemented");
+}
+
+}
+