.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "tutorials/04_tables.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_tutorials_04_tables.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_tutorials_04_tables.py:


Tables and updates
======================
A permission table records which combinations of read, write, and share are
allowed. Construct a circuit directly from Boolean rows, update the allowed
set, and query it with another Boolean condition.

.. GENERATED FROM PYTHON SOURCE LINES 10-23

.. code-block:: Python

    from tididi import Vtree, from_models, literal

    vtree = Vtree.balanced(3)
    read, write, share = 1, 2, 3
    rows = [
        (True, False, False),
        (True, True, False),
        (True, False, True),
        (True, True, False),
    ]
    permissions = from_models(vtree, [read, write, share], rows)
    print("Distinct permission sets:", permissions.model_count())





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    Distinct permission sets: 3




.. GENERATED FROM PYTHON SOURCE LINES 24-31

Rows describe a set: the repeated row contributes only once. The positions
in each row correspond to the supplied variable list. Other vtree variables,
if any, would be free.

Insert the combination with all three permissions and remove read/write
without sharing. Updates use signed literals; ``-share`` means sharing is
false. The operation consumes the old circuit and returns its replacement.

.. GENERATED FROM PYTHON SOURCE LINES 31-34

.. code-block:: Python

    permissions = permissions.update(insert=[[read, write, share]], remove=[[read, write, -share]])
    print("After updates:", permissions.model_count())





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    After updates: 3




.. GENERATED FROM PYTHON SOURCE LINES 35-37

The updated table contains read-only, read-and-share, and all three permissions.
Filter a copy so the full table stays available for the next update.

.. GENERATED FROM PYTHON SOURCE LINES 37-40

.. code-block:: Python

    sharing = permissions.copy() & literal(vtree, share)
    print("Permission sets allowing sharing:", sharing.model_count())





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    Permission sets allowing sharing: 2




.. GENERATED FROM PYTHON SOURCE LINES 41-46

Remove a group of rows
----------------------
Suppose sharing is withdrawn entirely. A partial assignment names just the
permissions to match: ``[share]`` selects every row where sharing is true,
whatever its read and write values.

.. GENERATED FROM PYTHON SOURCE LINES 46-49

.. code-block:: Python

    permissions = permissions.update(remove=[[share]])
    print("After withdrawing sharing:", permissions.model_count())





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    After withdrawing sharing: 1




.. GENERATED FROM PYTHON SOURCE LINES 50-52

Only read access without write or share remains. Removing matching rows does
not change their share column to false. An empty cube matches all assignments.


.. _sphx_glr_download_tutorials_04_tables.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: 04_tables.ipynb <04_tables.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: 04_tables.py <04_tables.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: 04_tables.zip <04_tables.zip>`