--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/thirdparty/attr/_next_gen.py	Mon Nov 21 15:04:42 2022 -0500
@@ -0,0 +1,220 @@
+# SPDX-License-Identifier: MIT
+
+"""
+These are Python 3.6+-only and 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,
+    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``.
+    """
+
+    def do_it(cls, auto_attribs):
+        return attrs(
+            maybe_cls=cls,
+            these=these,
+            repr=repr,
+            hash=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,
+    converter=None,
+    factory=None,
+    kw_only=False,
+    eq=None,
+    order=None,
+    on_setattr=None,
+):
+    """
+    Identical to `attr.ib`, except keyword-only and with some arguments
+    removed.
+
+    .. versionadded:: 20.1.0
+    """
+    return attrib(
+        default=default,
+        validator=validator,
+        repr=repr,
+        hash=hash,
+        init=init,
+        metadata=metadata,
+        converter=converter,
+        factory=factory,
+        kw_only=kw_only,
+        eq=eq,
+        order=order,
+        on_setattr=on_setattr,
+    )
+
+
+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
+    )