gistfile1.txt

  m_executor = std::shared_ptr<pdal::PipelineExecutor>(new pdal::PipelineExecutor(json));

    pdal::PipelineManager& manager = m_executor->getManager();

    std::stringstream strm(json);
    manager.readPipeline(strm);


    pdal::Stage *r = manager.getStage();
    if (!r)
        throw pdal::pdal_error("pipeline had no stages!");

    std::cout << "stage name: " << r->getName() << std::endl;

    int counter = 1;
    for (auto array: arrays)
    {
        // Create numpy reader for each array
        pdal::Options options;
        std::stringstream tag;
        tag << "readers_numpy" << counter;
        pdal::StageCreationOptions opts { "", "readers.numpy", nullptr, options, tag.str()};
        pdal::Stage& reader = manager.makeReader(opts);

        pdal::NumpyReader* np_reader = dynamic_cast<pdal::NumpyReader*>(&reader);
        if (!np_reader)
            throw pdal::pdal_error("couldn't cast reader!");

        PyObject* parray = (PyObject*)array->getPythonArray();
        if (!parray)
            throw pdal::pdal_error("array was none!");

        np_reader->setArray(parray);

        r->setInput(reader);
            std::cout << "stage name: " << r->getName() << std::endl;

        counter++;

    }

    strm.str("");
    pdal::PipelineWriter::writePipeline(r, strm);
    std::cout << strm.str() << std::endl;
    manager.validateStageOptions();
     const std::vector<pdal::Stage *> stages = manager.stages();
     std::cout << "num stages:" << stages.size() << std::endl;
     const std::vector<pdal::Stage *> roots = manager.roots();
     std::cout << "roots:" << roots.size() << std::endl;

     const std::vector<pdal::Stage *> leaves = manager.leaves();
     std::cout << "leaves:" << leaves.size() << std::endl;

  "pipeline":
  [
    {
      "tag": "readers_numpy1",
      "type": "readers.numpy"
    },
    {
      "tag": "readers_numpy2",
      "type": "readers.numpy"
    },
    {
      "tag": "readers_numpy3",
      "type": "readers.numpy"
    },
    {
      "capacity": "25",
      "inputs":
      [
        "readers_numpy1",
        "readers_numpy2",
        "readers_numpy3"
      ],
      "tag": "filters_chipper1",
      "type": "filters.chipper"
    }
  ]
}```