Function FindStreets

libs/search/streets_matcher.cpp:46–136

}

void FindStreets(BaseContext const & ctx, CBV const & candidates, FeaturesFilter const & filter,
                 QueryParams const & params, size_t startToken, bool withMisprints,
                 vector<StreetsMatcher::Prediction> & predictions)
{
  // Here we try to match as many tokens as possible while
  // intersection is a non-empty bit vector of streets. Single
  // tokens that are synonyms to streets are ignored.  Moreover,
  // each time a token that looks like a beginning of a house number
  // is met, we try to use current intersection of tokens as a
  // street layer and try to match BUILDINGs or POIs.
  CBV streets(candidates);

  CBV all;
  all.SetFull();

  size_t curToken = startToken;

  // This variable is used for prevention of duplicate calls to
  // CreateStreetsLayerAndMatchLowerLayers() with the same
  // arguments.
  size_t lastToken = startToken;

  // When true, no bit vectors were intersected with |streets| at all.
  bool emptyIntersection = true;

  auto emit = [&]()
  {
    if (streets.IsEmpty() || emptyIntersection || lastToken == curToken)
      return;

    CBV fs(streets);
    CBV fa(all);

    ASSERT(!fs.IsFull(), ());
    ASSERT(!fa.IsFull(), ());

    if (filter.NeedToFilter(fs))
      fs = filter.Filter(fs);

    if (fs.IsEmpty())
      return;

    if (filter.NeedToFilter(fa))
      fa = filter.Filter(fa).Union(fs);

    predictions.emplace_back();
    auto & prediction = predictions.back();

    prediction.m_tokenRange = TokenRange(startToken, curToken);

    ASSERT_NOT_EQUAL(fs.PopCount(), 0, ());
    ASSERT_LESS_OR_EQUAL(fs.PopCount(), fa.PopCount(), ());
    prediction.m_prob = static_cast<double>(fs.PopCount()) / static_cast<double>(fa.PopCount());

    prediction.m_features = std::move(fs);
    prediction.m_hash = prediction.m_features.Hash();
    prediction.m_withMisprints = withMisprints;
  };