httk.store.backend.mongo.evaluator
==================================

.. py:module:: httk.store.backend.mongo.evaluator

.. autoapi-nested-parse::

   Exact three-valued evaluation for Mongo stored-property predicates.

   The Mongo query path deliberately evaluates this small, frozen AST over
   hydrated records.  That is important for child records: document storage keeps
   their content-addressed SID links, while ``MongoStore.fetch`` gives the
   evaluator their exact Python values.



Classes
-------

.. autoapisummary::

   httk.store.backend.mongo.evaluator.MongoScope
   httk.store.backend.mongo.evaluator.MongoValue
   httk.store.backend.mongo.evaluator.MongoPredicate


Functions
---------

.. autoapisummary::

   httk.store.backend.mongo.evaluator.evaluate
   httk.store.backend.mongo.evaluator.canonical_predicate


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

.. py:class:: MongoScope

   A root, child, reference, or filtered record-object scope.


   .. py:attribute:: identifier
      :type:  int


   .. py:attribute:: schema
      :type:  httk.store.backend.schema.TableSchema


   .. py:attribute:: parent
      :type:  MongoScope | None
      :value: None



   .. py:attribute:: relationship
      :type:  httk.store.backend.schema.FieldSpec | None
      :value: None



   .. py:attribute:: filter_predicate
      :type:  MongoPredicate | None
      :value: None



   .. py:attribute:: scalar_child
      :type:  bool
      :value: False



   .. py:attribute:: context
      :type:  Any
      :value: None



   .. py:method:: field(name)

      Select a scalar field from this scope.



   .. py:method:: scope(name)

      Follow one child or reference relationship from this scope.



.. py:class:: MongoValue

   A field, aggregate, null, or literal value in the neutral AST.


   .. py:attribute:: kind
      :type:  Literal['field', 'store_timestamp', 'logical_id', 'alt_kind', 'alternative_id', 'present', 'constant', 'null', 'count', 'distinct_count']


   .. py:attribute:: scope
      :type:  MongoScope | None
      :value: None



   .. py:attribute:: field
      :type:  str | None
      :value: None



   .. py:attribute:: spec
      :type:  httk.store.backend.schema.FieldSpec | None
      :value: None



   .. py:attribute:: literal
      :type:  object


   .. py:attribute:: value
      :type:  MongoValue | None
      :value: None



.. py:class:: MongoPredicate

   A frozen three-valued predicate in the neutral stored-property AST.


   .. py:attribute:: kind
      :type:  Literal['constant', 'compare', 'is_null', 'exists', 'and', 'or', 'not', 'when_known', 'scaled']


   .. py:attribute:: operands
      :type:  tuple[object, Ellipsis]
      :value: ()



.. py:function:: evaluate(predicate, record, store_timestamp_resolver = None, logical_id_resolver = None, alt_kind_resolver = None)

   Evaluate ``predicate`` exactly over a hydrated backing object.

   :param predicate: Frozen predicate produced by ``_MongoQueryContext``.
   :param record: Hydrated backing record for the candidate SID.
   :param store_timestamp_resolver: Optional resolver for the candidate's store timestamp.
   :param logical_id_resolver: Optional resolver for the candidate's store-managed lineage id.
   :param alt_kind_resolver: Optional resolver for the candidate's store-managed alternative kind.
   :return: ``True``, ``False``, or ``None`` for SQL UNKNOWN.


.. py:function:: canonical_predicate(predicate)

   Return canonical JSON used as the verifier identity and cursor input.