Unify soft alignments in decoder and scorer

src/data/alignment.cpp

@@ -34,7 +34,6 @@ std::string WordAlignment::toString() const {
 
 WordAlignment ConvertSoftAlignToHardAlign(SoftAlignment alignSoft,
                                           float threshold /*= 1.f*/,
-                                          bool reversed /*= true*/,
                                           bool skipEOS /*= false*/) {
   size_t shift = alignSoft.size() > 0 && skipEOS ? 1 : 0;
   WordAlignment align;
@@ -42,10 +41,9 @@ WordAlignment ConvertSoftAlignToHardAlign(SoftAlignment alignSoft,
   if(threshold == 1.f) {
     for(size_t t = 0; t < alignSoft.size() - shift; ++t) {
       // Retrieved alignments are in reversed order
-      size_t rev = reversed ? alignSoft.size() - t - 1 : t;
       size_t maxArg = 0;
       for(size_t s = 0; s < alignSoft[0].size(); ++s) {
-        if(alignSoft[rev][maxArg] < alignSoft[rev][s]) {
+        if(alignSoft[t][maxArg] < alignSoft[t][s]) {
           maxArg = s;
         }
       }
@@ -55,9 +53,8 @@ WordAlignment ConvertSoftAlignToHardAlign(SoftAlignment alignSoft,
     // Alignments by greather-than-threshold
     for(size_t t = 0; t < alignSoft.size() - shift; ++t) {
       // Retrieved alignments are in reversed order
-      size_t rev = reversed ? alignSoft.size() - t - 1 : t;
       for(size_t s = 0; s < alignSoft[0].size(); ++s) {
-        if(alignSoft[rev][s] > threshold) {
+        if(alignSoft[t][s] > threshold) {
           align.push_back(s, t);
         }
       }
@@ -70,20 +67,17 @@ WordAlignment ConvertSoftAlignToHardAlign(SoftAlignment alignSoft,
   return align;
 }
 
-std::string SoftAlignToString(SoftAlignment align,
-                              bool reversed /*= true*/,
-                              bool skipEOS /*= false*/) {
+std::string SoftAlignToString(SoftAlignment align, bool skipEOS /*= false*/) {
   std::stringstream str;
   size_t shift = align.size() > 0 && skipEOS ? 1 : 0;
   bool first = true;
   for(size_t t = 0; t < align.size() - shift; ++t) {
-    size_t rev = reversed ? align.size() - t - 1 : t;
     if(!first)
       str << " ";
-    for(size_t s = 0; s < align[rev].size(); ++s) {
+    for(size_t s = 0; s < align[t].size(); ++s) {
       if(s != 0)
         str << ",";
-      str << align[rev][s];
+      str << align[t][s];
     }
     first = false;
   }

src/data/alignment.h

@@ -51,12 +51,9 @@ typedef std::vector<std::vector<float>> SoftAlignment;
 
 WordAlignment ConvertSoftAlignToHardAlign(SoftAlignment alignSoft,
                                           float threshold = 1.f,
-                                          bool reversed = true,
                                           bool skipEOS = false);
 
-std::string SoftAlignToString(SoftAlignment align,
-                              bool reversed = true,
-                              bool skipEOS = false);
+std::string SoftAlignToString(SoftAlignment align, bool skipEOS = false);
 
 }  // namespace data
 }  // namespace marian

src/rescorer/score_collector.h

@@ -87,13 +87,11 @@ protected:
 
   std::string getAlignment(const data::SoftAlignment& align) {
     if(alignment_ == "soft") {
-      return data::SoftAlignToString(align, false, true);
+      return data::SoftAlignToString(align, true);
     } else if(alignment_ == "hard") {
-      return data::ConvertSoftAlignToHardAlign(align, 1.f, false, true)
-          .toString();
+      return data::ConvertSoftAlignToHardAlign(align, 1.f, true).toString();
     } else if(alignmentThreshold_ > 0.f) {
-      return data::ConvertSoftAlignToHardAlign(
-                 align, alignmentThreshold_, false, true)
+      return data::ConvertSoftAlignToHardAlign(align, alignmentThreshold_, true)
           .toString();
     } else {
       ABORT("Unrecognized word alignment type");

src/translator/output_printer.cpp

@@ -4,14 +4,17 @@ namespace marian {
 
 std::string OutputPrinter::getAlignment(const Ptr<Hypothesis>& hyp) {
   data::SoftAlignment align;
-  // Skip EOS
+  // skip EOS
   auto last = hyp->GetPrevHyp();
-  // Get soft alignments for each target word
+  // get soft alignments for each target word starting from the last token
   while(last->GetPrevHyp().get() != nullptr) {
     align.push_back(last->GetAlignment());
     last = last->GetPrevHyp();
   }
 
+  // reverse alignments
+  std::reverse(align.begin(), align.end());
+
   if(alignment_ == "soft") {
     return data::SoftAlignToString(align);
   } else if(alignment_ == "hard") {