interfaces: introduce and use a protocol class for the `base85` module See f2832de2a46c for details when this was done for the `bdiff` module. It looks like PEP-688 removed the special casing of `bytes` being a standin for any type of `ByteString`, and defines a `typing.Buffer` class (with a backport in `typing_extensions` for Python prior to 3.12). There's been a lot of churn in this area with pytype, but recent versions of pytype and PyCharm recognize this, and e.g. have `mercurial.node.hex()` defined as: from typing_extensions import Buffer def hex(data: Buffer, sep: str | bytes = ..., bytes_per_sep: int = ...) -> bytes This covers `bytes`, `bytearray`, and `memoryview` by default. Both of the C functions here use `y#` to parse the arguments, which means the arg is a byte-like object[2], so the args would appear to be better typed as `Buffer`. However, pytype has a bug that prevents using this from `typing_extensions`[3], and mypy complained `Unsupported left operand type for + ("memoryview")` in the pure module on line 37 (meaning it's only a subset of `Buffer`). So hold off on changing any of that for now. [1] https://peps.python.org/pep-0688/#no-special-meaning-for-bytes [2] https://docs.python.org/3/glossary.html#term-bytes-like-object [3] https://github.com/google/pytype/issues/1772

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# modules.py - protocol classes for dynamically loaded modules

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#

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# This software may be used and distributed according to the terms of the

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# GNU General Public License version 2 or any later version.

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from __future__ import annotations

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import typing

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from typing import (

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    Callable,

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    List,

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    Optional,

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    Protocol,

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    Tuple,

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)

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if typing.TYPE_CHECKING:

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    BDiffBlock = Tuple[int, int, int, int]

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    """An entry in the list returned by bdiff.{xdiff,}blocks()."""

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    BDiffBlocksFnc = Callable[[bytes, bytes], List[BDiffBlock]]

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    """The signature of `bdiff.blocks()` and `bdiff.xdiffblocks()`."""

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class Base85(Protocol):

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    """A Protocol class for the various base85 module implementations."""

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    def b85encode(self, text: bytes, pad: bool = False) -> bytes:

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        """encode text in base85 format"""

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    def b85decode(self, text: bytes) -> bytes:

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        """decode base85-encoded text"""

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class BDiff(Protocol):

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    """A Protocol class for the various bdiff module implementations."""

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    def splitnewlines(self, text: bytes) -> List[bytes]:

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        """like str.splitlines, but only split on newlines."""

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    def bdiff(self, a: bytes, b: bytes) -> bytes:

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        ...

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    def blocks(self, a: bytes, b: bytes) -> List[BDiffBlock]:

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        ...

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    def fixws(self, text: bytes, allws: bool) -> bytes:

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        ...

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    xdiffblocks: Optional[BDiffBlocksFnc]

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    """This method is currently only available in the ``cext`` module."""