Development
-----------

:Release: 0.9.1
:Date: TBD

.. warning::
   This release is still under active development.  All changes listed are
   subject to change at any time.


Highlights
~~~~~~~~~~

None

Enhancements
~~~~~~~~~~~~

* Added masking to :class:`zipline.pipeline.CustomFactor`.
  Custom factors can now be passed a Filter upon instantiation. This tells the
  factor to only compute over stocks for which the filter returns True, rather
  than always computing over the entire universe of stocks. (:issue:`1095`)

Experimental Features
~~~~~~~~~~~~~~~~~~~~~

.. warning::

   Experimental features are subject to change.

None

Bug Fixes
~~~~~~~~~

None

Performance
~~~~~~~~~~~

None

Maintenance and Refactorings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

None

Build
~~~~~

None

Documentation
~~~~~~~~~~~~~

None

Miscellaneous
~~~~~~~~~~~~~

None

Development
-----------

:Release: 0.9.1
:Date: TBD

.. warning::
   This release is still under active development.  All changes listed are
   subject to change at any time.


Highlights
~~~~~~~~~~

None

Enhancements
~~~~~~~~~~~~

* Added masking to :class:`zipline.pipeline.CustomFactor`.
  Custom factors can now be passed a Filter upon instantiation. This tells the
  factor to only compute over stocks for which the filter returns True, rather
  than always computing over the entire universe of stocks. (:issue:`1095`)

* Added :class:`zipline.utils.cache.ExpiringCache`.
  A cache which wraps entries in a :class:`zipline.utils.cache.CachedObject`,
  which manages expiration of entries based on the `dt` supplied to the `get`
  method.

Experimental Features
~~~~~~~~~~~~~~~~~~~~~

.. warning::

   Experimental features are subject to change.

None

Bug Fixes
~~~~~~~~~

None

Performance
~~~~~~~~~~~

None

Maintenance and Refactorings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

None

Build
~~~~~

None

Documentation
~~~~~~~~~~~~~

None

Miscellaneous
~~~~~~~~~~~~~

None

Add whatsnew entry for ExpiringCache.
DOC: Add whatsnew entry for ExpiringCache.
