Junhui's implementation of soft syntax constraint features

4 files changed, 781 insertions, 0 deletions

diff --git a/decoder/Makefile.am b/decoder/Makefile.am
index cc52ccd4..2f293b15 100644
--- a/decoder/Makefile.am
+++ b/decoder/Makefile.am
@@ -59,6 +59,7 @@ libcdec_a_SOURCES = \
   ff_rules.h \
   ff_ruleshape.h \
   ff_sample_fsa.h \
+  ff_soft_syn.h \
   ff_soft_syntax.h \
   ff_soft_syntax_mindist.h \
   ff_source_path.h \
@@ -122,6 +123,7 @@ libcdec_a_SOURCES = \
   ff_parse_match.cc \
   ff_rules.cc \
   ff_ruleshape.cc \
+  ff_soft_syn.cc \
   ff_soft_syntax.cc \
   ff_soft_syntax_mindist.cc \
   ff_source_path.cc \
diff --git a/decoder/cdec_ff.cc b/decoder/cdec_ff.cc
index 6f7227aa..973a643a 100644
--- a/decoder/cdec_ff.cc
+++ b/decoder/cdec_ff.cc
@@ -15,6 +15,7 @@
 #include "ff_rules.h"
 #include "ff_ruleshape.h"
 #include "ff_bleu.h"
+#include "ff_soft_syn.h"
 #include "ff_soft_syntax.h"
 #include "ff_soft_syntax_mindist.h"
 #include "ff_source_path.h"
@@ -80,4 +81,5 @@ void register_feature_functions() {
   ff_registry.Register("WordSet", new FFFactory<WordSet>);
   ff_registry.Register("ConstReorderFeature", new FFFactory<ConstReorderFeature>);
   ff_registry.Register("External", new FFFactory<ExternalFeature>);
+  ff_registry.Register("SoftSynFeature", new SoftSynFeatureFactory());
 }
diff --git a/decoder/ff_soft_syn.cc b/decoder/ff_soft_syn.cc
new file mode 100644
index 00000000..da840008
--- /dev/null
+++ b/decoder/ff_soft_syn.cc
@@ -0,0 +1,687 @@
+/*
+ * ff_soft_syn.cc
+ *
+ */
+#include "ff_soft_syn.h"
+#include "stringlib.h"
+#include "hg.h"
+#include "sentence_metadata.h"
+#include "tree.h"
+#include "synutils.h"
+
+#include <string>
+#include <vector>
+#include <stdio.h>
+
+using namespace std;
+
+typedef HASH_MAP<std::string, vector<string> > MapFeatures;
+
+/*
+ * Note:
+ *      In BOLT experiments, we need to merged some sequence words into one term
+ *(like from "1999 nian 1 yue 10 ri" to "1999_nian_1_yue_10_ri") due to some
+ *reasons;
+ *      but in the parse file, we still use the parse tree before merging any
+ *words;
+ *      therefore, the words in source sentence and parse tree diverse and we
+ *need to map a word in merged sentence into its original index;
+ *      a word in source sentence maps 1 or more words in parse tree
+ *      the index map info is stored at variable index_map_;
+ *      if the index_map_ is NULL, indicating the word index in source sentence
+ *and parse tree is always same.
+ *
+ */
+
+struct SoftSynFeatureImpl {
+  SoftSynFeatureImpl(const string& params) {
+    parsed_tree_ = NULL;
+    index_map_ = NULL;
+
+    map_features_ = NULL;
+  }
+
+  ~SoftSynFeatureImpl() { FreeSentenceVariables(); }
+
+  static int ReserveStateSize() { return 2 * sizeof(uint16_t); }
+
+  void InitializeInputSentence(const std::string& parse_file,
+                               const std::string& index_map_file) {
+    FreeSentenceVariables();
+    parsed_tree_ = ReadParseTree(parse_file);
+
+    if (index_map_file != "") ReadIndexMap(index_map_file);
+
+    // we can do the features "off-line"
+    map_features_ = new MapFeatures();
+    InitializeFeatures(map_features_);
+  }
+
+  void ReadIndexMap(const std::string& index_map_file) {
+    STxtFileReader* reader = new STxtFileReader(index_map_file.c_str());
+    char szLine[10001];
+    szLine[0] = '\0';
+    reader->fnReadNextLine(szLine, NULL);
+    vector<string> terms;
+    SplitOnWhitespace(string(szLine), &terms);
+
+    index_map_ = new short int[terms.size() + 1];
+    int ix = 0;
+    size_t i;
+    for (i = 0; i < terms.size(); i++) {
+      index_map_[i] = ix;
+      ix += atoi(terms[i].c_str());
+    }
+    index_map_[i] = ix;
+    assert(parsed_tree_ == NULL || ix == parsed_tree_->m_vecTerminals.size());
+    delete reader;
+  }
+
+  void MapIndex(short int begin, short int end, short int& mapped_begin,
+                short int& mapped_end) {
+    if (index_map_ == NULL) {
+      mapped_begin = begin;
+      mapped_end = end;
+      return;
+    }
+
+    mapped_begin = index_map_[begin];
+    mapped_end = index_map_[end + 1] - 1;
+  }
+
+  /*
+   * ff_const_reorder.cc::ConstReorderFeatureImpl also defines this function
+   */
+  void FindConsts(const SParsedTree* tree, int begin, int end,
+                  vector<STreeItem*>& consts) {
+    STreeItem* item;
+    item = tree->m_vecTerminals[begin]->m_ptParent;
+    while (true) {
+      while (item->m_ptParent != NULL &&
+             item->m_ptParent->m_iBegin == item->m_iBegin &&
+             item->m_ptParent->m_iEnd <= end)
+        item = item->m_ptParent;
+
+      if (item->m_ptParent == NULL && item->m_vecChildren.size() == 1 &&
+          strcmp(item->m_pszTerm, "ROOT") == 0)
+        item = item->m_vecChildren[0];  // we automatically add a "ROOT" node at
+                                        // the top, skip it if necessary.
+
+      consts.push_back(item);
+      if (item->m_iEnd < end)
+        item = tree->m_vecTerminals[item->m_iEnd + 1]->m_ptParent;
+      else
+        break;
+    }
+  }
+
+  /*
+   * according to Marton & Resnik (2008)
+   * a span cann't have both X+ style and X= style features
+   * a constituent XP is crossed only if the span not only covers parts of XP's
+   *content, but also covers one or more words outside XP
+   * a span may have X+, Y+
+   *
+   * (note, we refer X* features to X= features in Marton & Resnik (2008))
+   */
+  void GenerateSoftFeature(int begin, int end, const SParsedTree* tree,
+                           vector<string>& vecFeature) {
+    vector<STreeItem*> vecNode;
+    FindConsts(tree, begin, end, vecNode);
+
+    if (vecNode.size() == 1) {
+      // match to one constituent
+      string feature_name = string(vecNode[0]->m_pszTerm) + string("*");
+      vecFeature.push_back(feature_name);
+    } else {
+      // match to multiple constituents, find the lowest common parent (lcp)
+      STreeItem* lcp = vecNode[0];
+      while (lcp->m_iEnd < end) lcp = lcp->m_ptParent;
+
+      for (size_t i = 0; i < vecNode.size(); i++) {
+        STreeItem* item = vecNode[i];
+
+        while (item != lcp) {
+          if (item->m_iBegin < begin || item->m_iEnd > end) {
+            // item is crossed
+            string feature_name = string(item->m_pszTerm) + string("+");
+            vecFeature.push_back(feature_name);
+          }
+          if (item->m_iBrotherIndex > 0 &&
+              item->m_ptParent->m_vecChildren[item->m_iBrotherIndex - 1]
+                      ->m_iBegin >= begin &&
+              item->m_ptParent->m_vecChildren[item->m_iBrotherIndex - 1]
+                      ->m_iEnd <= end)
+            break;  // we don't want to collect crossed constituents twice
+          item = item->m_ptParent;
+        }
+      }
+    }
+  }
+
+  void GenerateSoftFeatureFromFlattenedTree(int begin, int end,
+                                            const SParsedTree* tree,
+                                            vector<string>& vecFeature) {
+    vector<STreeItem*> vecNode;
+    FindConsts(tree, begin, end, vecNode);
+
+    if (vecNode.size() == 1) {
+      // match to one constituent
+      string feature_name = string(vecNode[0]->m_pszTerm) + string("*");
+      vecFeature.push_back(feature_name);
+    } else {
+      // match to multiple constituents, see if they have a common parent
+      size_t i = 0;
+      for (i = 1; i < vecNode.size(); i++) {
+        if (vecNode[i]->m_ptParent != vecNode[0]->m_ptParent) break;
+      }
+      if (i == vecNode.size()) {
+        // they share a common parent
+        string feature_name =
+            string(vecNode[0]->m_ptParent->m_pszTerm) + string("&");
+        vecFeature.push_back(feature_name);
+      } else {
+        // they don't share a common parent, find the lowest common parent (lcp)
+        STreeItem* lcp = vecNode[0];
+        while (lcp->m_iEnd < end) lcp = lcp->m_ptParent;
+
+        for (size_t i = 0; i < vecNode.size(); i++) {
+          STreeItem* item = vecNode[i];
+
+          while (item != lcp) {
+            if (item->m_iBegin < begin || item->m_iEnd > end) {
+              // item is crossed
+              string feature_name = string(item->m_pszTerm) + string("+");
+              vecFeature.push_back(feature_name);
+            }
+            if (item->m_iBrotherIndex > 0 &&
+                item->m_ptParent->m_vecChildren[item->m_iBrotherIndex - 1]
+                        ->m_iBegin >= begin &&
+                item->m_ptParent->m_vecChildren[item->m_iBrotherIndex - 1]
+                        ->m_iEnd <= end)
+              break;  // we don't want to collect crossed constituents twice
+            item = item->m_ptParent;
+          }
+        }
+      }
+    }
+  }
+
+  void SetSoftSynFeature(const Hypergraph::Edge& edge,
+                         SparseVector<double>* features,
+                         const vector<const void*>& ant_states, void* state) {
+    vector<uint16_t> vec_pos;
+    if (parsed_tree_ == NULL) return;
+
+    uint16_t* remnant = reinterpret_cast<uint16_t*>(state);
+
+    short int mapped_begin, mapped_end;
+    MapIndex(edge.i_, edge.j_ - 1, mapped_begin, mapped_end);
+
+    remnant[0] = mapped_begin;
+    remnant[1] = mapped_end;
+
+    for (size_t i = 0; i < edge.tail_nodes_.size(); i++) {
+      const uint16_t* astate = reinterpret_cast<const uint16_t*>(ant_states[i]);
+      vec_pos.push_back(astate[0]);
+      vec_pos.push_back(astate[1]);
+    }
+
+    // soft feature for the whole span
+    const vector<string> vecFeature =
+        GenerateSoftFeature(mapped_begin, mapped_end, map_features_);
+    for (size_t i = 0; i < vecFeature.size(); i++) {
+      int f_id = FD::Convert(vecFeature[i]);
+      if (f_id) features->set_value(f_id, 1);
+    }
+  }
+
+ private:
+  const vector<string>& GenerateSoftFeature(int begin, int end,
+                                            MapFeatures* map_features) {
+    string key;
+    GenerateKey(begin, end, key);
+    MapFeatures::const_iterator iter = (*map_features).find(key);
+    assert(iter != map_features->end());
+    return iter->second;
+  }
+
+  void Byte_to_Char(unsigned char* str, int n) {
+    str[0] = (n & 255);
+    str[1] = n / 256;
+  }
+
+  void GenerateKey(int begin, int end, string& key) {
+    unsigned char szTerm[1001];
+    Byte_to_Char(szTerm, begin);
+    Byte_to_Char(szTerm + 2, end);
+    szTerm[4] = '\0';
+    key = string(szTerm, szTerm + 4);
+  }
+
+  void InitializeFeatures(MapFeatures* map_features) {
+    if (parsed_tree_ == NULL) return;
+
+    for (size_t i = 0; i < parsed_tree_->m_vecTerminals.size(); i++)
+      for (size_t j = i; j < parsed_tree_->m_vecTerminals.size(); j++) {
+        vector<string> vecFeature;
+        GenerateSoftFeature(i, j, parsed_tree_, vecFeature);
+        string key;
+        GenerateKey(i, j, key);
+        (*map_features)[key] = vecFeature;
+      }
+  }
+
+  void FreeSentenceVariables() {
+    if (parsed_tree_ != NULL) delete parsed_tree_;
+    if (index_map_ != NULL) delete[] index_map_;
+    index_map_ = NULL;
+
+    if (map_features_ != NULL) delete map_features_;
+  }
+
+  SParsedTree* ReadParseTree(const std::string& parse_file) {
+    SParseReader* reader = new SParseReader(parse_file.c_str(), false);
+    SParsedTree* tree = reader->fnReadNextParseTree();
+    // assert(tree != NULL);
+    delete reader;
+    return tree;
+  }
+
+ private:
+  SParsedTree* parsed_tree_;
+
+  short int* index_map_;
+
+  MapFeatures* map_features_;
+};
+
+SoftSynFeature::SoftSynFeature(std::string param) {
+  pimpl_ = new SoftSynFeatureImpl(param);
+  SetStateSize(SoftSynFeatureImpl::ReserveStateSize());
+  name_ = "SoftSynFeature";
+}
+
+SoftSynFeature::~SoftSynFeature() { delete pimpl_; }
+
+void SoftSynFeature::PrepareForInput(const SentenceMetadata& smeta) {
+  string parse_file = smeta.GetSGMLValue("parse");
+  assert(parse_file != "");
+
+  string indexmap_file = smeta.GetSGMLValue("index-map");
+
+  pimpl_->InitializeInputSentence(parse_file, indexmap_file);
+}
+
+void SoftSynFeature::TraversalFeaturesImpl(
+    const SentenceMetadata& /* smeta */, const Hypergraph::Edge& edge,
+    const vector<const void*>& ant_states, SparseVector<double>* features,
+    SparseVector<double>* estimated_features, void* state) const {
+  pimpl_->SetSoftSynFeature(edge, features, ant_states, state);
+}
+
+string SoftSynFeature::usage(bool /*param*/, bool /*verbose*/) {
+  return "SoftSynFeature";
+}
+
+boost::shared_ptr<FeatureFunction> CreateSoftSynFeatureModel(
+    std::string param) {
+  SoftSynFeature* ret = new SoftSynFeature(param);
+  return boost::shared_ptr<FeatureFunction>(ret);
+}
+
+boost::shared_ptr<FeatureFunction> SoftSynFeatureFactory::Create(
+    std::string param) const {
+  return CreateSoftSynFeatureModel(param);
+}
+
+std::string SoftSynFeatureFactory::usage(bool params, bool verbose) const {
+  return SoftSynFeature::usage(params, verbose);
+}
+
+typedef HASH_MAP<std::string, double> MapDouble;
+typedef HASH_MAP<std::string, MapDouble*> MapDoubleFeatures;
+
+/*
+ * Note:
+ *      In BOLT experiments, we need to merged some sequence words into one term
+ *(like from "1999 nian 1 yue 10 ri" to "1999_nian_1_yue_10_ri") due to some
+ *reasons;
+ *      but in the parse file, we still use the parse tree before merging any
+ *words;
+ *      therefore, the words in source sentence and parse tree diverse and we
+ *need to map a word in merged sentence into its original index;
+ *      a word in source sentence maps 1 or more words in parse tree
+ *      the index map info is stored at variable index_map_;
+ *      if the index_map_ is NULL, indicating the word index in source sentence
+ *and parse tree is always same.
+ *
+ */
+
+struct SoftKBestSynFeatureImpl {
+  SoftKBestSynFeatureImpl(const string& params) {
+    index_map_ = NULL;
+
+    map_features_ = NULL;
+  }
+
+  ~SoftKBestSynFeatureImpl() { FreeSentenceVariables(); }
+
+  static int ReserveStateSize() { return 2 * sizeof(uint16_t); }
+
+  void InitializeInputSentence(const std::string& parse_file,
+                               const std::string& index_map_file) {
+    FreeSentenceVariables();
+    ReadParseTree(parse_file, vec_parsed_tree_, vec_tree_prob_);
+
+    if (index_map_file != "") ReadIndexMap(index_map_file);
+
+    // we can do the features "off-line"
+    map_features_ = new MapDoubleFeatures();
+    InitializeFeatures(map_features_);
+  }
+
+  void SetSoftKBestSynFeature(const Hypergraph::Edge& edge,
+                              SparseVector<double>* features,
+                              const vector<const void*>& ant_states,
+                              void* state) {
+    vector<uint16_t> vec_pos;
+    if (vec_parsed_tree_.size() == 0) return;
+
+    uint16_t* remnant = reinterpret_cast<uint16_t*>(state);
+
+    short int mapped_begin, mapped_end;
+    MapIndex(edge.i_, edge.j_ - 1, mapped_begin, mapped_end);
+
+    remnant[0] = mapped_begin;
+    remnant[1] = mapped_end;
+
+    for (size_t i = 0; i < edge.tail_nodes_.size(); i++) {
+      const uint16_t* astate = reinterpret_cast<const uint16_t*>(ant_states[i]);
+      vec_pos.push_back(astate[0]);
+      vec_pos.push_back(astate[1]);
+    }
+
+    // soft feature for the whole span
+    const MapDouble* pMapFeature =
+        GenerateSoftFeature(mapped_begin, mapped_end, map_features_);
+    for (MapDouble::const_iterator iter = pMapFeature->begin();
+         iter != pMapFeature->end(); iter++) {
+      int f_id = FD::Convert(iter->first);
+      if (f_id) features->set_value(f_id, iter->second);
+    }
+  }
+
+ private:
+  void ReadIndexMap(const std::string& index_map_file) {
+    STxtFileReader* reader = new STxtFileReader(index_map_file.c_str());
+    char szLine[10001];
+    szLine[0] = '\0';
+    reader->fnReadNextLine(szLine, NULL);
+    vector<string> terms;
+    SplitOnWhitespace(string(szLine), &terms);
+
+    index_map_ = new short int[terms.size() + 1];
+    int ix = 0;
+    size_t i;
+    for (i = 0; i < terms.size(); i++) {
+      index_map_[i] = ix;
+      ix += atoi(terms[i].c_str());
+    }
+    index_map_[i] = ix;
+    assert(vec_parsed_tree_.size() == 0 ||
+           ix == vec_parsed_tree_[0]->m_vecTerminals.size());
+    delete reader;
+  }
+
+  void MapIndex(short int begin, short int end, short int& mapped_begin,
+                short int& mapped_end) {
+    if (index_map_ == NULL) {
+      mapped_begin = begin;
+      mapped_end = end;
+      return;
+    }
+
+    mapped_begin = index_map_[begin];
+    mapped_end = index_map_[end + 1] - 1;
+  }
+
+  /*
+   * ff_const_reorder.cc::ConstReorderFeatureImpl also defines this function
+   */
+  void FindConsts(const SParsedTree* tree, int begin, int end,
+                  vector<STreeItem*>& consts) {
+    STreeItem* item;
+    item = tree->m_vecTerminals[begin]->m_ptParent;
+    while (true) {
+      while (item->m_ptParent != NULL &&
+             item->m_ptParent->m_iBegin == item->m_iBegin &&
+             item->m_ptParent->m_iEnd <= end)
+        item = item->m_ptParent;
+
+      if (item->m_ptParent == NULL && item->m_vecChildren.size() == 1 &&
+          strcmp(item->m_pszTerm, "ROOT") == 0)
+        item = item->m_vecChildren[0];  // we automatically add a "ROOT" node at
+                                        // the top, skip it if necessary.
+
+      consts.push_back(item);
+      if (item->m_iEnd < end)
+        item = tree->m_vecTerminals[item->m_iEnd + 1]->m_ptParent;
+      else
+        break;
+    }
+  }
+
+  /*
+   * according to Marton & Resnik (2008)
+   * a span cann't have both X+ style and X= style features
+   * a constituent XP is crossed only if the span not only covers parts of XP's
+   *content, but also covers one or more words outside XP
+   * a span may have X+, Y+
+   *
+   * (note, we refer X* features to X= features in Marton & Resnik (2008))
+   */
+  void GenerateSoftFeature(int begin, int end,
+                           const vector<SParsedTree*>& vec_tree,
+                           const vector<double>& vec_prob,
+                           MapDouble* pMapFeature) {
+
+    for (size_t i = 0; i < vec_tree.size(); i++) {
+      const SParsedTree* tree = vec_tree[i];
+      vector<STreeItem*> vecNode;
+      FindConsts(tree, begin, end, vecNode);
+
+      if (vecNode.size() == 1) {
+        // match to one constituent
+        string feature_name = string(vecNode[0]->m_pszTerm) + string("*");
+        MapDouble::iterator iter = pMapFeature->find(feature_name);
+        if (iter != pMapFeature->end()) {
+          iter->second += vec_prob[i];
+        } else
+          (*pMapFeature)[feature_name] = vec_prob[i];
+      } else {
+        // match to multiple constituents, find the lowest common parent (lcp)
+        STreeItem* lcp = vecNode[0];
+        while (lcp->m_iEnd < end) lcp = lcp->m_ptParent;
+
+        for (size_t j = 0; j < vecNode.size(); j++) {
+          STreeItem* item = vecNode[j];
+
+          while (item != lcp) {
+            if (item->m_iBegin < begin || item->m_iEnd > end) {
+              // item is crossed
+              string feature_name = string(item->m_pszTerm) + string("+");
+              MapDouble::iterator iter = pMapFeature->find(feature_name);
+              if (iter != pMapFeature->end()) {
+                iter->second += vec_prob[i];
+              } else
+                (*pMapFeature)[feature_name] = vec_prob[i];
+            }
+            if (item->m_iBrotherIndex > 0 &&
+                item->m_ptParent->m_vecChildren[item->m_iBrotherIndex - 1]
+                        ->m_iBegin >= begin &&
+                item->m_ptParent->m_vecChildren[item->m_iBrotherIndex - 1]
+                        ->m_iEnd <= end)
+              break;  // we don't want to collect crossed constituents twice
+            item = item->m_ptParent;
+          }
+        }
+      }
+    }
+  }
+
+  const MapDouble* GenerateSoftFeature(int begin, int end,
+                                       MapDoubleFeatures* map_features) {
+    string key;
+    GenerateKey(begin, end, key);
+    MapDoubleFeatures::const_iterator iter = (*map_features).find(key);
+    assert(iter != map_features->end());
+    return iter->second;
+  }
+
+  void Byte_to_Char(unsigned char* str, int n) {
+    str[0] = (n & 255);
+    str[1] = n / 256;
+  }
+
+  void GenerateKey(int begin, int end, string& key) {
+    unsigned char szTerm[1001];
+    Byte_to_Char(szTerm, begin);
+    Byte_to_Char(szTerm + 2, end);
+    szTerm[4] = '\0';
+    key = string(szTerm, szTerm + 4);
+  }
+
+  void InitializeFeatures(MapDoubleFeatures* map_features) {
+    if (vec_parsed_tree_.size() == 0) return;
+
+    const SParsedTree* pTree = vec_parsed_tree_[0];
+
+    vector<double> vec_prob;
+    vec_prob.reserve(vec_tree_prob_.size());
+    double tmp = 0.0;
+    for (size_t i = 0; i < vec_tree_prob_.size(); i++) {
+      vec_prob.push_back(pow(10, vec_tree_prob_[i] - vec_tree_prob_[0]));
+      tmp += vec_prob[i];
+    }
+    for (size_t i = 0; i < vec_prob.size(); i++) vec_prob[i] /= tmp;
+
+    for (size_t i = 0; i < pTree->m_vecTerminals.size(); i++)
+      for (size_t j = i; j < pTree->m_vecTerminals.size(); j++) {
+        MapDouble* pMap = new MapDouble();
+        GenerateSoftFeature(i, j, vec_parsed_tree_, vec_prob, pMap);
+        string key;
+        GenerateKey(i, j, key);
+        (*map_features)[key] = pMap;
+      }
+  }
+
+  void FreeSentenceVariables() {
+    for (size_t i = 0; i < vec_parsed_tree_.size(); i++) {
+      if (vec_parsed_tree_[i] != NULL) delete vec_parsed_tree_[i];
+    }
+    vec_parsed_tree_.clear();
+    vec_tree_prob_.clear();
+    if (index_map_ != NULL) delete[] index_map_;
+    index_map_ = NULL;
+
+    if (map_features_ != NULL) {
+      for (MapDoubleFeatures::iterator iter = map_features_->begin();
+           iter != map_features_->end(); iter++)
+        delete iter->second;
+      delete map_features_;
+    }
+  }
+
+  void ReadParseTree(const std::string& parse_file,
+                     vector<SParsedTree*>& vec_tree, vector<double>& vec_prob) {
+    STxtFileReader* reader = new STxtFileReader(parse_file.c_str());
+    SParsedTree* tree;
+    string line;
+    while (reader->fnReadNextLine(line)) {
+      const char* p = strchr(line.c_str(), ' ');
+      assert(p != NULL);
+      string strProb = line.substr(0, line.find(' '));
+      tree = SParsedTree::fnConvertFromString(p + 1);
+      tree->fnSetSpanInfo();
+      tree->fnSetHeadWord();
+      vec_tree.push_back(tree);
+      if (strProb == string("-Infinity")) {
+        vec_prob.push_back(-99.0);
+        break;
+      } else {
+        vec_prob.push_back(atof(strProb.c_str()));
+      }
+    }
+    delete reader;
+  }
+
+  void ReadParseTree2(const std::string& parse_file,
+                      vector<SParsedTree*>& vec_tree,
+                      vector<double>& vec_prob) {
+    SParseReader* reader = new SParseReader(parse_file.c_str(), false);
+    double prob;
+    SParsedTree* tree;
+    while ((tree = reader->fnReadNextParseTreeWithProb(&prob)) != NULL) {
+      vec_tree.push_back(tree);
+      if (std::isinf(prob)) {
+        vec_prob.push_back(-99);
+        break;
+      } else
+        vec_prob.push_back(prob);
+    }
+    // assert(tree != NULL);
+    delete reader;
+  }
+
+ private:
+  vector<SParsedTree*> vec_parsed_tree_;
+  vector<double> vec_tree_prob_;
+
+  short int* index_map_;
+
+  MapDoubleFeatures* map_features_;
+};
+
+SoftKBestSynFeature::SoftKBestSynFeature(std::string param) {
+  pimpl_ = new SoftKBestSynFeatureImpl(param);
+  SetStateSize(SoftKBestSynFeatureImpl::ReserveStateSize());
+  name_ = "SoftKBestSynFeature";
+}
+
+SoftKBestSynFeature::~SoftKBestSynFeature() { delete pimpl_; }
+
+void SoftKBestSynFeature::PrepareForInput(const SentenceMetadata& smeta) {
+  string parse_file = smeta.GetSGMLValue("kbestparse");
+  assert(parse_file != "");
+
+  string indexmap_file = smeta.GetSGMLValue("index-map");
+
+  pimpl_->InitializeInputSentence(parse_file, indexmap_file);
+}
+
+void SoftKBestSynFeature::TraversalFeaturesImpl(
+    const SentenceMetadata& /* smeta */, const Hypergraph::Edge& edge,
+    const vector<const void*>& ant_states, SparseVector<double>* features,
+    SparseVector<double>* estimated_features, void* state) const {
+  pimpl_->SetSoftKBestSynFeature(edge, features, ant_states, state);
+}
+
+string SoftKBestSynFeature::usage(bool /*param*/, bool /*verbose*/) {
+  return "SoftKBestSynFeature";
+}
+
+boost::shared_ptr<FeatureFunction> CreateSoftKBestSynFeatureModel(
+    std::string param) {
+  SoftKBestSynFeature* ret = new SoftKBestSynFeature(param);
+  return boost::shared_ptr<FeatureFunction>(ret);
+}
+
+boost::shared_ptr<FeatureFunction> SoftKBestSynFeatureFactory::Create(
+    std::string param) const {
+  return CreateSoftKBestSynFeatureModel(param);
+}
+
+std::string SoftKBestSynFeatureFactory::usage(bool params, bool verbose) const {
+  return SoftKBestSynFeature::usage(params, verbose);
+}
diff --git a/decoder/ff_soft_syn.h b/decoder/ff_soft_syn.h
new file mode 100644
index 00000000..21618bc0
--- /dev/null
+++ b/decoder/ff_soft_syn.h
@@ -0,0 +1,90 @@
+/*
+ * ff_soft_syn.h
+ *
+ */
+
+#ifndef FF_SOFT_SYN_H_
+#define FF_SOFT_SYN_H_
+
+#include "ff_factory.h"
+#include "ff.h"
+
+struct SoftSynFeatureImpl;
+
+class SoftSynFeature : public FeatureFunction {
+ public:
+  SoftSynFeature(std::string param);
+  ~SoftSynFeature();
+  static std::string usage(bool param, bool verbose);
+
+ protected:
+  virtual void PrepareForInput(const SentenceMetadata& smeta);
+
+  virtual void TraversalFeaturesImpl(
+      const SentenceMetadata& smeta, const HG::Edge& edge,
+      const std::vector<const void*>& ant_contexts,
+      SparseVector<double>* features, SparseVector<double>* estimated_features,
+      void* out_context) const;
+
+ private:
+  SoftSynFeatureImpl* pimpl_;
+};
+
+struct SoftSynFeatureFactory : public FactoryBase<FeatureFunction> {
+  FP Create(std::string param) const;
+  std::string usage(bool params, bool verbose) const;
+};
+
+struct SoftKBestSynFeatureImpl;
+
+class SoftKBestSynFeature : public FeatureFunction {
+ public:
+  SoftKBestSynFeature(std::string param);
+  ~SoftKBestSynFeature();
+  static std::string usage(bool param, bool verbose);
+
+ protected:
+  virtual void PrepareForInput(const SentenceMetadata& smeta);
+
+  virtual void TraversalFeaturesImpl(
+      const SentenceMetadata& smeta, const HG::Edge& edge,
+      const std::vector<const void*>& ant_contexts,
+      SparseVector<double>* features, SparseVector<double>* estimated_features,
+      void* out_context) const;
+
+ private:
+  SoftKBestSynFeatureImpl* pimpl_;
+};
+
+struct SoftKBestSynFeatureFactory : public FactoryBase<FeatureFunction> {
+  FP Create(std::string param) const;
+  std::string usage(bool params, bool verbose) const;
+};
+
+struct SoftForestSynFeatureImpl;
+
+class SoftForestSynFeature : public FeatureFunction {
+ public:
+  SoftForestSynFeature(std::string param);
+  ~SoftForestSynFeature();
+  static std::string usage(bool param, bool verbose);
+
+ protected:
+  virtual void PrepareForInput(const SentenceMetadata& smeta);
+
+  virtual void TraversalFeaturesImpl(
+      const SentenceMetadata& smeta, const HG::Edge& edge,
+      const std::vector<const void*>& ant_contexts,
+      SparseVector<double>* features, SparseVector<double>* estimated_features,
+      void* out_context) const;
+
+ private:
+  SoftForestSynFeatureImpl* pimpl_;
+};
+
+struct SoftForestSynFeatureFactory : public FactoryBase<FeatureFunction> {
+  FP Create(std::string param) const;
+  std::string usage(bool params, bool verbose) const;
+};
+
+#endif /* FF_SOFT_SYN_H_ */