use new union api

5 files changed, 75 insertions, 5 deletions

diff --git a/decoder/Makefile.am b/decoder/Makefile.am
index 0a792549..4a98a4f1 100644
--- a/decoder/Makefile.am
+++ b/decoder/Makefile.am
@@ -44,6 +44,7 @@ libcdec_a_SOURCES = \
   hg_remove_eps.cc \
   decoder.cc \
   hg_intersect.cc \
+  hg_union.cc \
   hg_sampler.cc \
   factored_lexicon_helper.cc \
   viterbi.cc \
diff --git a/decoder/decoder.cc b/decoder/decoder.cc
index a6f7b1ce..a69a6d05 100644
--- a/decoder/decoder.cc
+++ b/decoder/decoder.cc
@@ -24,6 +24,7 @@
 #include "hg.h"
 #include "sentence_metadata.h"
 #include "hg_intersect.h"
+#include "hg_union.h"
 
 #include "oracle_bleu.h"
 #include "apply_models.h"
@@ -980,7 +981,7 @@ bool DecoderImpl::Decode(const string& input, DecoderObserver* o) {
         bool succeeded = HypergraphIO::ReadFromJSON(rf.stream(), &new_hg);
         if (!succeeded) abort();
       }
-      new_hg.Union(forest);
+      HG::Union(forest, &new_hg);
       bool succeeded = writer.Write(new_hg, false);
       if (!succeeded) abort();
     } else {
@@ -1067,7 +1068,7 @@ bool DecoderImpl::Decode(const string& input, DecoderObserver* o) {
             bool succeeded = HypergraphIO::ReadFromJSON(rf.stream(), &new_hg);
             if (!succeeded) abort();
           }
-          new_hg.Union(forest);
+          HG::Union(forest, &new_hg);
           bool succeeded = writer.Write(new_hg, false);
           if (!succeeded) abort();
         } else {
diff --git a/decoder/hg_test.cc b/decoder/hg_test.cc
index 92ed98b2..c47af850 100644
--- a/decoder/hg_test.cc
+++ b/decoder/hg_test.cc
@@ -6,6 +6,7 @@
 
 #include "json_parse.h"
 #include "hg_intersect.h"
+#include "hg_union.h"
 #include "viterbi.h"
 #include "kbest.h"
 #include "inside_outside.h"
@@ -52,7 +53,7 @@ BOOST_AUTO_TEST_CASE(Union) {
   int l2 = ViterbiPathLength(hg2);
   cerr << c1 << "\t" << TD::GetString(t1) << endl;
   cerr << c2 << "\t" << TD::GetString(t2) << endl;
-  hg1.Union(hg2);
+  HG::Union(hg2, &hg1);
   hg1.Reweight(wts);
   c3 = ViterbiESentence(hg1, &t3);
   int l3 = ViterbiPathLength(hg1);
@@ -121,8 +122,8 @@ BOOST_AUTO_TEST_CASE(InsideScore) {
   vector<prob_t> post;
   inside = hg.ComputeBestPathThroughEdges(&post);
   BOOST_CHECK_CLOSE(-0.3, log(inside), 1e-4);  // computed by hand
-  BOOST_CHECK_EQUAL(post.size(), 4);
-  for (int i = 0; i < 4; ++i) {
+  BOOST_CHECK_EQUAL(post.size(), 5);
+  for (int i = 0; i < 5; ++i) {
     cerr << "edge post: " << log(post[i]) << '\t' << hg.edges_[i].rule_->AsString() << endl;
   }
 }
diff --git a/decoder/hg_union.cc b/decoder/hg_union.cc
new file mode 100644
index 00000000..37082976
--- /dev/null
+++ b/decoder/hg_union.cc
@@ -0,0 +1,58 @@
+#include "hg_union.h"
+
+#include "hg.h"
+
+using namespace std;
+
+namespace HG {
+
+void Union(const Hypergraph& in, Hypergraph* out) {
+  if (&in == out) return;
+  if (out->nodes_.empty()) {
+    out->nodes_ = in.nodes_;
+    out->edges_ = in.edges_; return;
+  }
+  unsigned noff = out->nodes_.size();
+  unsigned eoff = out->edges_.size();
+  int ogoal = in.nodes_.size() - 1;
+  int cgoal = noff - 1;
+  // keep a single goal node, so add nodes.size - 1
+  out->nodes_.resize(out->nodes_.size() + ogoal);
+  // add all edges
+  out->edges_.resize(out->edges_.size() + in.edges_.size());
+
+  for (int i = 0; i < ogoal; ++i) {
+    const Hypergraph::Node& on = in.nodes_[i];
+    Hypergraph::Node& cn = out->nodes_[i + noff];
+    cn.id_ = i + noff;
+    cn.in_edges_.resize(on.in_edges_.size());
+    for (unsigned j = 0; j < on.in_edges_.size(); ++j)
+      cn.in_edges_[j] = on.in_edges_[j] + eoff;
+
+    cn.out_edges_.resize(on.out_edges_.size());
+    for (unsigned j = 0; j < on.out_edges_.size(); ++j)
+      cn.out_edges_[j] = on.out_edges_[j] + eoff;
+  }
+
+  for (unsigned i = 0; i < in.edges_.size(); ++i) {
+    const Hypergraph::Edge& oe = in.edges_[i];
+    Hypergraph::Edge& ce = out->edges_[i + eoff];
+    ce.id_ = i + eoff;
+    ce.rule_ = oe.rule_;
+    ce.feature_values_ = oe.feature_values_;
+    if (oe.head_node_ == ogoal) {
+      ce.head_node_ = cgoal;
+      out->nodes_[cgoal].in_edges_.push_back(ce.id_);
+    } else {
+      ce.head_node_ = oe.head_node_ + noff;
+    }
+    ce.tail_nodes_.resize(oe.tail_nodes_.size());
+    for (unsigned j = 0; j < oe.tail_nodes_.size(); ++j)
+      ce.tail_nodes_[j] = oe.tail_nodes_[j] + noff;
+  }
+
+  out->TopologicallySortNodesAndEdges(cgoal);
+}
+
+}
+
diff --git a/decoder/hg_union.h b/decoder/hg_union.h
new file mode 100644
index 00000000..34624246
--- /dev/null
+++ b/decoder/hg_union.h
@@ -0,0 +1,9 @@
+#ifndef _HG_UNION_H_
+#define _HG_UNION_H_
+
+class Hypergraph;
+namespace HG {
+  void Union(const Hypergraph& in, Hypergraph* out);
+};
+
+#endif