diff options
Diffstat (limited to 'third_party/python/attrs/attr/_next_gen.py')
| -rw-r--r-- | third_party/python/attrs/attr/_next_gen.py | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/third_party/python/attrs/attr/_next_gen.py b/third_party/python/attrs/attr/_next_gen.py new file mode 100644 index 0000000000..8f7c0b9a46 --- /dev/null +++ b/third_party/python/attrs/attr/_next_gen.py @@ -0,0 +1,232 @@ +# SPDX-License-Identifier: MIT + +""" +These are keyword-only APIs that call `attr.s` and `attr.ib` with different +default values. +""" + + +from functools import partial + +from . import setters +from ._funcs import asdict as _asdict +from ._funcs import astuple as _astuple +from ._make import ( + NOTHING, + _frozen_setattrs, + _ng_default_on_setattr, + attrib, + attrs, +) +from .exceptions import UnannotatedAttributeError + + +def define( + maybe_cls=None, + *, + these=None, + repr=None, + unsafe_hash=None, + hash=None, + init=None, + slots=True, + frozen=False, + weakref_slot=True, + str=False, + auto_attribs=None, + kw_only=False, + cache_hash=False, + auto_exc=True, + eq=None, + order=False, + auto_detect=True, + getstate_setstate=None, + on_setattr=None, + field_transformer=None, + match_args=True, +): + r""" + Define an *attrs* class. + + Differences to the classic `attr.s` that it uses underneath: + + - Automatically detect whether or not *auto_attribs* should be `True` (c.f. + *auto_attribs* parameter). + - If *frozen* is `False`, run converters and validators when setting an + attribute by default. + - *slots=True* + + .. caution:: + + Usually this has only upsides and few visible effects in everyday + programming. But it *can* lead to some suprising behaviors, so please + make sure to read :term:`slotted classes`. + - *auto_exc=True* + - *auto_detect=True* + - *order=False* + - Some options that were only relevant on Python 2 or were kept around for + backwards-compatibility have been removed. + + Please note that these are all defaults and you can change them as you + wish. + + :param Optional[bool] auto_attribs: If set to `True` or `False`, it behaves + exactly like `attr.s`. If left `None`, `attr.s` will try to guess: + + 1. If any attributes are annotated and no unannotated `attrs.fields`\ s + are found, it assumes *auto_attribs=True*. + 2. Otherwise it assumes *auto_attribs=False* and tries to collect + `attrs.fields`\ s. + + For now, please refer to `attr.s` for the rest of the parameters. + + .. versionadded:: 20.1.0 + .. versionchanged:: 21.3.0 Converters are also run ``on_setattr``. + .. versionadded:: 22.2.0 + *unsafe_hash* as an alias for *hash* (for :pep:`681` compliance). + """ + + def do_it(cls, auto_attribs): + return attrs( + maybe_cls=cls, + these=these, + repr=repr, + hash=hash, + unsafe_hash=unsafe_hash, + init=init, + slots=slots, + frozen=frozen, + weakref_slot=weakref_slot, + str=str, + auto_attribs=auto_attribs, + kw_only=kw_only, + cache_hash=cache_hash, + auto_exc=auto_exc, + eq=eq, + order=order, + auto_detect=auto_detect, + collect_by_mro=True, + getstate_setstate=getstate_setstate, + on_setattr=on_setattr, + field_transformer=field_transformer, + match_args=match_args, + ) + + def wrap(cls): + """ + Making this a wrapper ensures this code runs during class creation. + + We also ensure that frozen-ness of classes is inherited. + """ + nonlocal frozen, on_setattr + + had_on_setattr = on_setattr not in (None, setters.NO_OP) + + # By default, mutable classes convert & validate on setattr. + if frozen is False and on_setattr is None: + on_setattr = _ng_default_on_setattr + + # However, if we subclass a frozen class, we inherit the immutability + # and disable on_setattr. + for base_cls in cls.__bases__: + if base_cls.__setattr__ is _frozen_setattrs: + if had_on_setattr: + raise ValueError( + "Frozen classes can't use on_setattr " + "(frozen-ness was inherited)." + ) + + on_setattr = setters.NO_OP + break + + if auto_attribs is not None: + return do_it(cls, auto_attribs) + + try: + return do_it(cls, True) + except UnannotatedAttributeError: + return do_it(cls, False) + + # maybe_cls's type depends on the usage of the decorator. It's a class + # if it's used as `@attrs` but ``None`` if used as `@attrs()`. + if maybe_cls is None: + return wrap + else: + return wrap(maybe_cls) + + +mutable = define +frozen = partial(define, frozen=True, on_setattr=None) + + +def field( + *, + default=NOTHING, + validator=None, + repr=True, + hash=None, + init=True, + metadata=None, + type=None, + converter=None, + factory=None, + kw_only=False, + eq=None, + order=None, + on_setattr=None, + alias=None, +): + """ + Identical to `attr.ib`, except keyword-only and with some arguments + removed. + + .. versionadded:: 23.1.0 + The *type* parameter has been re-added; mostly for + {func}`attrs.make_class`. Please note that type checkers ignore this + metadata. + .. versionadded:: 20.1.0 + """ + return attrib( + default=default, + validator=validator, + repr=repr, + hash=hash, + init=init, + metadata=metadata, + type=type, + converter=converter, + factory=factory, + kw_only=kw_only, + eq=eq, + order=order, + on_setattr=on_setattr, + alias=alias, + ) + + +def asdict(inst, *, recurse=True, filter=None, value_serializer=None): + """ + Same as `attr.asdict`, except that collections types are always retained + and dict is always used as *dict_factory*. + + .. versionadded:: 21.3.0 + """ + return _asdict( + inst=inst, + recurse=recurse, + filter=filter, + value_serializer=value_serializer, + retain_collection_types=True, + ) + + +def astuple(inst, *, recurse=True, filter=None): + """ + Same as `attr.astuple`, except that collections types are always retained + and `tuple` is always used as the *tuple_factory*. + + .. versionadded:: 21.3.0 + """ + return _astuple( + inst=inst, recurse=recurse, filter=filter, retain_collection_types=True + ) |