Added character-level BLEU metric

1 files changed, 93 insertions, 0 deletions

diff --git a/mteval/comb_scorer.cc b/mteval/comb_scorer.cc
index 9fc37868..63f327ca 100644
--- a/mteval/comb_scorer.cc
+++ b/mteval/comb_scorer.cc
@@ -95,3 +95,96 @@ ScoreP BLEUTERCombinationScorer::ScoreFromString(const std::string& in) {
   r->ter = SentenceScorer::CreateScoreFromString(TER, in.substr(1 + bss));
   return ScoreP(r);
 }
+
+
+class BLEUCBLEUCombinationScore : public ScoreBase<BLEUCBLEUCombinationScore> {
+  friend class BLEUCBLEUCombinationScorer;
+ public:
+  ~BLEUCBLEUCombinationScore();
+  float ComputePartialScore() const { return 0.0;}
+  float ComputeScore() const {
+    return (bleu->ComputeScore() + cbleu->ComputeScore()) / 2.0f;
+  }
+  void ScoreDetails(string* details) const {
+    char buf[160];
+    sprintf(buf, "Combi = %.2f, BLEU = %.2f, CBLEU = %.2f",
+      ComputeScore()*100.0f, bleu->ComputeScore()*100.0f, cbleu->ComputeScore()*100.0f);
+    *details = buf;
+  }
+  void PlusPartialEquals(const Score& rhs, int oracle_e_cover, int oracle_f_cover, int src_len){}
+
+  void PlusEquals(const Score& delta, const float scale) {
+    bleu->PlusEquals(*static_cast<const BLEUCBLEUCombinationScore&>(delta).bleu, scale);
+    cbleu->PlusEquals(*static_cast<const BLEUCBLEUCombinationScore&>(delta).cbleu, scale);
+  }
+  void PlusEquals(const Score& delta) {
+    bleu->PlusEquals(*static_cast<const BLEUCBLEUCombinationScore&>(delta).bleu);
+    cbleu->PlusEquals(*static_cast<const BLEUCBLEUCombinationScore&>(delta).cbleu);
+  }
+
+
+
+  ScoreP GetOne() const {
+    BLEUCBLEUCombinationScore* res = new BLEUCBLEUCombinationScore;
+    res->bleu = bleu->GetOne();
+    res->cbleu = cbleu->GetOne();
+    return ScoreP(res);
+  }
+  ScoreP GetZero() const {
+    BLEUCBLEUCombinationScore* res = new BLEUCBLEUCombinationScore;
+    res->bleu = bleu->GetZero();
+    res->cbleu = cbleu->GetZero();
+    return ScoreP(res);
+  }
+  void Subtract(const Score& rhs, Score* res) const {
+    bleu->Subtract(*static_cast<const BLEUCBLEUCombinationScore&>(rhs).bleu,
+                   static_cast<BLEUCBLEUCombinationScore*>(res)->bleu.get());
+    cbleu->Subtract(*static_cast<const BLEUCBLEUCombinationScore&>(rhs).cbleu,
+                  static_cast<BLEUCBLEUCombinationScore*>(res)->cbleu.get());
+  }
+  void Encode(std::string* out) const {
+    string bs, ts;
+    bleu->Encode(&bs);
+    cbleu->Encode(&ts);
+    out->clear();
+    (*out) += static_cast<char>(bs.size());
+    (*out) += bs;
+    (*out) += ts;
+  }
+  bool IsAdditiveIdentity() const {
+    return bleu->IsAdditiveIdentity() && cbleu->IsAdditiveIdentity();
+  }
+ private:
+  ScoreP bleu;
+  ScoreP cbleu;
+};
+
+BLEUCBLEUCombinationScore::~BLEUCBLEUCombinationScore() {
+}
+
+BLEUCBLEUCombinationScorer::BLEUCBLEUCombinationScorer(const vector<vector<WordID> >& refs) {
+  bleu_ = SentenceScorer::CreateSentenceScorer(IBM_BLEU, refs);
+  cbleu_ = SentenceScorer::CreateSentenceScorer(CBLEU, refs);
+}
+
+BLEUCBLEUCombinationScorer::~BLEUCBLEUCombinationScorer() {
+}
+
+ScoreP BLEUCBLEUCombinationScorer::ScoreCCandidate(const vector<WordID>& hyp) const {
+  return ScoreP();
+}
+
+ScoreP BLEUCBLEUCombinationScorer::ScoreCandidate(const std::vector<WordID>& hyp) const {
+  BLEUCBLEUCombinationScore* res = new BLEUCBLEUCombinationScore;
+  res->bleu = bleu_->ScoreCandidate(hyp);
+  res->cbleu = cbleu_->ScoreCandidate(hyp);
+  return ScoreP(res);
+}
+
+ScoreP BLEUCBLEUCombinationScorer::ScoreFromString(const std::string& in) {
+  int bss = in[0];
+  BLEUCBLEUCombinationScore* r = new BLEUCBLEUCombinationScore;
+  r->bleu = SentenceScorer::CreateScoreFromString(IBM_BLEU, in.substr(1, bss));
+  r->cbleu = SentenceScorer::CreateScoreFromString(CBLEU, in.substr(1 + bss));
+  return ScoreP(r);
+}