Source code for ax.utils.common.docutils

#!/usr/bin/env python3
# Copyright (c) Meta Platforms, Inc. and affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.

# pyre-strict

"""Support functions for sphinx et. al
"""


from typing import Any, Callable, TypeVar


_T = TypeVar("_T")


# pyre-fixme[2]: Parameter annotation cannot contain `Any`.
# pyre-ignore[34]: T77127616
[docs]def copy_doc(src: Callable[..., Any]) -> Callable[[_T], _T]: """A decorator that copies the docstring of another object Since ``sphinx`` actually loads the python modules to grab the docstrings this works with both ``sphinx`` and the ``help`` function. .. code:: python class Cat(Mamal): @property @copy_doc(Mamal.is_feline) def is_feline(self) -> true: ... """ # It would be tempting to try to get the doc through the class the method # is bound to (via __self__) but decorators are called before __self__ is # assigned. # One other solution would be to use a decorator on classes that would fill # all the missing docstrings but we want to be able to detect syntactically # when docstrings are copied to keep things nice and simple if src.__doc__ is None: raise ValueError(f"{src.__qualname__} has no docstring to copy") def copy_doc(dst: _T) -> _T: if dst.__doc__ is not None: # pyre-fixme[16]: `_T` has no attribute `__qualname__`. raise ValueError(f"{dst.__qualname__} already has a docstring") dst.__doc__ = src.__doc__ return dst return copy_doc