first span features

1 files changed, 50 insertions, 0 deletions

diff --git a/decoder/ff_spans.cc b/decoder/ff_spans.cc
new file mode 100644
index 00000000..6fa49d45
--- /dev/null
+++ b/decoder/ff_spans.cc
@@ -0,0 +1,50 @@
+#include "ff_spans.h"
+
+#include <sstream>
+#include <cassert>
+
+#include "sentence_metadata.h"
+#include "lattice.h"
+#include "fdict.h"
+
+using namespace std;
+
+SpanFeatures::SpanFeatures(const string& param) :
+  kS(TD::Convert("S") * -1),
+  kX(TD::Convert("X") * -1) {}
+
+void SpanFeatures::TraversalFeaturesImpl(const SentenceMetadata& smeta,
+                                         const Hypergraph::Edge& edge,
+                                         const vector<const void*>& ant_contexts,
+                                         SparseVector<double>* features,
+                                         SparseVector<double>* estimated_features,
+                                         void* context) const {
+//  char& res = *static_cast<char*>(context);
+//  res = edge.j_ - edge.i_;
+//  assert(res >= 0);
+  assert(edge.j_ < end_span_ids_.size());
+  assert(edge.j_ >= 0);
+  features->set_value(end_span_ids_[edge.j_], 1);
+
+  if (edge.Arity() == 2) {
+    const TRule& rule = *edge.rule_;
+    if (rule.f_[0] == kS && rule.f_[1] == kX) {
+//      char x_width = *static_cast<const char*>(ant_contexts[1]);
+    }
+  }
+}
+
+void SpanFeatures::PrepareForInput(const SentenceMetadata& smeta) {
+  const Lattice& lattice = smeta.GetSourceLattice();
+  WordID eos = TD::Convert("</s>");
+  end_span_ids_.resize(lattice.size() + 1);
+  for (int i = 0; i <= lattice.size(); ++i) {
+    WordID word = eos;
+    if (i < lattice.size())
+      word = lattice[i][0].label;  // rather arbitrary for lattices
+    ostringstream sfid;
+    sfid << "ES:" << TD::Convert(word);
+    end_span_ids_[i] = FD::Convert(sfid.str());
+  }
+}
+