path: root/decoder/ff_soft_syn.cc

/*
 * ff_soft_syn.cc
 *
 */
#include "ff_soft_syn.h"

#include "filelib.h"
#include "stringlib.h"
#include "hg.h"
#include "sentence_metadata.h"
#include "ff_const_reorder_common.h"

#include <string>
#include <vector>
#include <stdio.h>

using namespace std;
using namespace const_reorder;

typedef HASH_MAP<std::string, vector<string> > MapFeatures;

struct SoftSynFeatureImpl {
  SoftSynFeatureImpl(const string& /*params*/) {
    parsed_tree_ = NULL;
    map_features_ = NULL;
  }

  ~SoftSynFeatureImpl() { FreeSentenceVariables(); }

  void InitializeInputSentence(const std::string& parse_file) {
    FreeSentenceVariables();
    parsed_tree_ = ReadParseTree(parse_file);

    // we can do the features "off-line"
    map_features_ = new MapFeatures();
    InitializeFeatures(map_features_);
  }

  /*
   * 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) {
    if (parsed_tree_ == NULL) return;

    // soft feature for the whole span
    const vector<string> vecFeature =
        GenerateSoftFeature(edge.i_, edge.j_ - 1, 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 (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_;

  MapFeatures* map_features_;
};

SoftSynFeature::SoftSynFeature(std::string param) {
  pimpl_ = new SoftSynFeatureImpl(param);
  name_ = "SoftSynFeature";
}

SoftSynFeature::~SoftSynFeature() { delete pimpl_; }

void SoftSynFeature::PrepareForInput(const SentenceMetadata& smeta) {
  string parse_file = smeta.GetSGMLValue("parse");
  if (parse_file.empty()) {
    parse_file = smeta.GetSGMLValue("src_tree");
  }
  assert(parse_file.size());
  pimpl_->InitializeInputSentence(parse_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);
}

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);
}