Use bidicts for the backing ``_fwdm`` and ``_invm`` mappings,
obviating the need to store key and value data in linked list nodes.
Also drop the unnecessary ^ from the namedtuple identifier regexes.
- Refactor proxied- (i.e. delegated-) to-``_fwdm`` logic
for better composability and interoperability.
Drop the ``_Proxied*`` mixin classes
and instead move their methods
into :class:`~bidict.BidictBase`,
which now checks for an object defined by the
:attr:`~bidict.BidictBase.__delegate__` attribute.
The :attr:`~bidict.BidictBase.__delegate__` object
will be delegated to if the method is available on it,
otherwise a default implementation
(e.g. inherited from :class:`~collections.abc.Mapping`)
will be used otherwise.
Subclasses may set ``__delegate__ = None`` to opt out.
- Consolidate ``_MutableBidict`` into :class:`bidict.bidict`
now that the dropped mixin classes make it unnecessary.
- Change :attr:`~bidict.BidictBase.__repr_delegate__`
to take simply a type like :class:`dict` or :class:`list`.
- Upgrade to latest major
`sortedcontainers <https://github.com/grantjenks/python-sortedcontainers>`__
version (from v1 to v2)
for the :ref:`extending:Sorted Bidict Recipes`.
- ``bidict.compat.{view,iter}{keys,values,items}`` on Python2
no longer assumes the target object implements these methods,
as they're not actually part of the
:class:`~collections.abc.Mapping` interface,
and provides fallback implementations when the methods are unavailable.
This allows the :ref:`extending:Sorted Bidict Recipes`
to continue to work with sortedcontainers v2 on Python2.
- Test code in docs via Sphinx rather than pytest.
Enables running Python version-dependent tests conditionally
rather than skipping them altogether, as well as hiding import
statements (via `testsetup`) that otherwise just add noise.
Run tests (viz. pytest and Sphinx doctest) via a new
run-tests.py script.
- Use less memory in the linked lists that back bidict.OrderedBidict
by storing node data unpacked rather than in (key, value) tuple objects.
- New _Sentinel subclass of _Node improves over old _make_sentinel code.