annotate mercurial/cext/mpatch.pyi @ 46038:8dca9051a859

cext: add .pyi files for C extensions

I'm unsure if all the annotations are completely accurate. But having
these helps type checkers reason about our C extensions.

Differential Revision: https://phab.mercurial-scm.org/D9281

from typing import (
    List,
)

version: int

class mpatchError(Exception): ...

def patches(text: bytes, bins: List[bytes]) -> bytes: ...
def patchedsize(orig: int, data: bytes) -> int: ...