Method Visit

cpp/src/arrow/dataset/forest_internal.h:90–115

  /// subtree should be skipped.
  template <typename PreVisitor, typename PostVisitor>
  Status Visit(PreVisitor&& pre, PostVisitor&& post) const {
    std::vector<Ref> parent_stack;

    for (int i = 0; i < size_; ++i) {
      Ref ref = {this, i};

      while (parent_stack.size() > 0) {
        if (parent_stack.back().IsAncestorOf(ref)) break;

        post(parent_stack.back());
        parent_stack.pop_back();
      }

      ARROW_ASSIGN_OR_RAISE(bool visit_subtree, pre(ref));

      if (!visit_subtree) {
        // skip descendants
        i += ref.num_descendants();
        continue;
      }

      parent_stack.push_back(ref);
    }

    return Status::OK();
  }

  Ref operator[](int i) const { return Ref{this, i}; }