##// END OF EJS Templates
interfaces: introduce and use a protocol class for the `bdiff` module...
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

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_version_info.py
86 lines | 2.1 KiB | text/x-python | PythonLexer
# SPDX-License-Identifier: MIT
from functools import total_ordering
from ._funcs import astuple
from ._make import attrib, attrs
@total_ordering
@attrs(eq=False, order=False, slots=True, frozen=True)
class VersionInfo:
"""
A version object that can be compared to tuple of length 1--4:
>>> attr.VersionInfo(19, 1, 0, "final") <= (19, 2)
True
>>> attr.VersionInfo(19, 1, 0, "final") < (19, 1, 1)
True
>>> vi = attr.VersionInfo(19, 2, 0, "final")
>>> vi < (19, 1, 1)
False
>>> vi < (19,)
False
>>> vi == (19, 2,)
True
>>> vi == (19, 2, 1)
False
.. versionadded:: 19.2
"""
year = attrib(type=int)
minor = attrib(type=int)
micro = attrib(type=int)
releaselevel = attrib(type=str)
@classmethod
def _from_version_string(cls, s):
"""
Parse *s* and return a _VersionInfo.
"""
v = s.split(".")
if len(v) == 3:
v.append("final")
return cls(
year=int(v[0]), minor=int(v[1]), micro=int(v[2]), releaselevel=v[3]
)
def _ensure_tuple(self, other):
"""
Ensure *other* is a tuple of a valid length.
Returns a possibly transformed *other* and ourselves as a tuple of
the same length as *other*.
"""
if self.__class__ is other.__class__:
other = astuple(other)
if not isinstance(other, tuple):
raise NotImplementedError
if not (1 <= len(other) <= 4):
raise NotImplementedError
return astuple(self)[: len(other)], other
def __eq__(self, other):
try:
us, them = self._ensure_tuple(other)
except NotImplementedError:
return NotImplemented
return us == them
def __lt__(self, other):
try:
us, them = self._ensure_tuple(other)
except NotImplementedError:
return NotImplemented
# Since alphabetically "dev0" < "final" < "post1" < "post2", we don't
# have to do anything special with releaselevel for now.
return us < them