view CONTRIBUTORS @ 51933:f2832de2a46c

interfaces: introduce and use a protocol class for the `bdiff` module

This is allowed by PEP 544[1], and we basically follow the example there.  The
class here is copied from `mercurial.pure.bdiff`, and the implementation
removed.

There are several modules that have a few different implementations, and the
implementation chosen is controlled by `HGMODULEPOLICY`.  The module is loaded
via `mercurial/policy.py`, and has been inferred by pytype as `Any` up to this
point.  Therefore it and PyCharm were blind to all functions on the module, and
their signatures.  Also, having multiple instances of the same module allows
their signatures to get out of sync.

Introducing a protocol class allows the loaded module that is stored in a
variable to be given type info, which cascades through the various places it is
used.  This change alters 11 *.pyi files, for example.  In theory, this would
also allow us to ensure the various implementations of the same module are kept
in alignment- simply import the module in a test module, attempt to pass it to a
function that uses the corresponding protocol as an argument, and run pytype on
it.

In practice, this doesn't work (yet).  PyCharm (erroneously) flags imported
modules being passed where a protocol class is used[2].  Pytype has problems the
other way- it fails to detect when a module that doesn't adhere to the protocol
is passed to a protocol argument.  The good news is that mypy properly detects
this case.  The bad news is that mypy spews a bunch of other errors when
importing even simple modules, like the various `bdiff` modules.  Therefore I'm
punting on the tests for now because the type info around a loaded module in
PyCharm is a clear win by itself.

[1] https://peps.python.org/pep-0544/#modules-as-implementations-of-protocols
[2] https://youtrack.jetbrains.com/issue/PY-58679/Support-modules-implementing-protocols

[This file is here for historical purposes, all recent contributors
should appear in the changelog directly]

Andrea Arcangeli <andrea at suse.de>
Thomas Arendsen Hein <thomas at intevation.de>
Goffredo Baroncelli <kreijack at libero.it>
Muli Ben-Yehuda <mulix at mulix.org>
Mikael Berthe <mikael at lilotux.net>
Benoit Boissinot <bboissin at gmail.com>
Brendan Cully <brendan at kublai.com>
Vincent Danjean <vdanjean.ml at free.fr>
Jake Edge <jake at edge2.net>
Michael Fetterman <michael.fetterman at intel.com>
Edouard Gomez <ed.gomez at free.fr>
Eric Hopper <hopper at omnifarious.org>
Alecs King <alecsk at gmail.com>
Volker Kleinfeld <Volker.Kleinfeld at gmx.de>
Vadim Lebedev <vadim at mbdsys.com>
Christopher Li <hg at chrisli.org>
Chris Mason <mason at suse.com>
Colin McMillen <mcmillen at cs.cmu.edu>
Wojciech Milkowski <wmilkowski at interia.pl>
Chad Netzer <chad.netzer at gmail.com>
Bryan O'Sullivan <bos at serpentine.com>
Vicent Seguí Pascual <vseguip at gmail.com>
Sean Perry <shaleh at speakeasy.net>
Nguyen Anh Quynh <aquynh at gmail.com>
Ollivier Robert <roberto at keltia.freenix.fr>
Alexander Schremmer <alex at alexanderweb.de>
Arun Sharma <arun at sharma-home.net>
Josef "Jeff" Sipek <jeffpc at optonline.net>
Kevin Smith <yarcs at qualitycode.com>
TK Soh <teekaysoh at yahoo.com>
Radoslaw Szkodzinski <astralstorm at gorzow.mm.pl>
Samuel Tardieu <sam at rfc1149.net>
K Thananchayan <thananck at yahoo.com>
Andrew Thompson <andrewkt at aktzero.com>
Michael S. Tsirkin <mst at mellanox.co.il>
Rafael Villar Burke <pachi at mmn-arquitectos.com>
Tristan Wibberley <tristan at wibberley.org>
Mark Williamson <mark.williamson at cl.cam.ac.uk>