pyextal.jaxJoint.engine
=======================

.. py:module:: pyextal.jaxJoint.engine

.. autoapi-nested-parse::

   Keeping the Fortran engine on the dataset being worked on.

   ``bloch_parse`` loads one ``.dat`` into the engine's module state, and several
   things the refinement needs read that state rather than anything passed to
   them: `get_bloch_constants`, the symmetry operations (`spgr`, used by
   `GroupSymmetry` and `appliedSymmetry`), `lookupSF`/``defaultsf``, and
   ``beamcheck`` -- which `calculate_tilt_dependent_values` calls per tilt, at
   setup and at every geometry rebuild. With several datasets the engine must hold
   the right one whenever any of these runs, so every such step goes through
   `EngineSwitch.activate`.

   Re-parsing is safe: the engine's allocators release the previous arrays first.
   ``terminate()`` is not: it ends the engine for the life of the process, so it
   must never run between datasets. jaxJoint never calls ``bloch_run``, so there is
   nothing to terminate at the end either.



Attributes
----------

.. autoapisummary::

   pyextal.jaxJoint.engine.MAX_DAT_PATH


Classes
-------

.. autoapisummary::

   pyextal.jaxJoint.engine.EngineSwitch


Module Contents
---------------

.. py:data:: MAX_DAT_PATH
   :value: 120


.. py:class:: EngineSwitch

   Parses each dataset's ``.dat`` into the engine on demand.

   Datasets are added in order; `activate` re-parses only when the engine holds
   a different ``.dat``, so two datasets built against the same file never
   re-parse between them.


   .. py:attribute:: _dats
      :value: []



   .. py:attribute:: _params


   .. py:attribute:: _beams


   .. py:attribute:: _loaded
      :value: None



   .. py:attribute:: _tmp
      :value: None



   .. py:attribute:: parses
      :value: 0



   .. py:method:: add(dat)

      Registers a dataset's ``.dat`` and returns its index.



   .. py:method:: _short(dat)


   .. py:method:: record(d, constants)

      Remembers the beam list dataset ``d``'s setup was built with.



   .. py:method:: activate(d)

      Makes the engine hold dataset ``d``'s ``.dat``.

      :param d: Dataset index.
      :type d: int

      :returns: From that dataset's ``bloch_parse``.
      :rtype: SimParams

      :raises RuntimeError: If the re-parsed beam list differs from the one the
          dataset was set up with.



   .. py:method:: _check(d)