Mercurial > public > mercurial-scm > hg
diff mercurial/thirdparty/attr/_funcs.py @ 34397:765eb17a7eb8
thirdparty: vendor attrs
The attrs package allows defining namedtuple-like classes with no weird
behavior and no runtime performance cost.
This patch vendors in attrs 17.2.0.
# no-check-commit
Differential Revision: https://phab.mercurial-scm.org/D867
author | Siddharth Agarwal <sid0@fb.com> |
---|---|
date | Sun, 01 Oct 2017 04:14:16 -0700 |
parents | |
children | e1c586b9a43c |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mercurial/thirdparty/attr/_funcs.py Sun Oct 01 04:14:16 2017 -0700 @@ -0,0 +1,212 @@ +from __future__ import absolute_import, division, print_function + +import copy + +from ._compat import iteritems +from ._make import NOTHING, fields, _obj_setattr +from .exceptions import AttrsAttributeNotFoundError + + +def asdict(inst, recurse=True, filter=None, dict_factory=dict, + retain_collection_types=False): + """ + Return the ``attrs`` attribute values of *inst* as a dict. + + Optionally recurse into other ``attrs``-decorated classes. + + :param inst: Instance of an ``attrs``-decorated class. + :param bool recurse: Recurse into classes that are also + ``attrs``-decorated. + :param callable filter: A callable whose return code deteremines whether an + attribute or element is included (``True``) or dropped (``False``). Is + called with the :class:`attr.Attribute` as the first argument and the + value as the second argument. + :param callable dict_factory: A callable to produce dictionaries from. For + example, to produce ordered dictionaries instead of normal Python + dictionaries, pass in ``collections.OrderedDict``. + :param bool retain_collection_types: Do not convert to ``list`` when + encountering an attribute whose type is ``tuple`` or ``set``. Only + meaningful if ``recurse`` is ``True``. + + :rtype: return type of *dict_factory* + + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. versionadded:: 16.0.0 *dict_factory* + .. versionadded:: 16.1.0 *retain_collection_types* + """ + attrs = fields(inst.__class__) + rv = dict_factory() + for a in attrs: + v = getattr(inst, a.name) + if filter is not None and not filter(a, v): + continue + if recurse is True: + if has(v.__class__): + rv[a.name] = asdict(v, recurse=True, filter=filter, + dict_factory=dict_factory) + elif isinstance(v, (tuple, list, set)): + cf = v.__class__ if retain_collection_types is True else list + rv[a.name] = cf([ + asdict(i, recurse=True, filter=filter, + dict_factory=dict_factory) + if has(i.__class__) else i + for i in v + ]) + elif isinstance(v, dict): + df = dict_factory + rv[a.name] = df(( + asdict(kk, dict_factory=df) if has(kk.__class__) else kk, + asdict(vv, dict_factory=df) if has(vv.__class__) else vv) + for kk, vv in iteritems(v)) + else: + rv[a.name] = v + else: + rv[a.name] = v + return rv + + +def astuple(inst, recurse=True, filter=None, tuple_factory=tuple, + retain_collection_types=False): + """ + Return the ``attrs`` attribute values of *inst* as a tuple. + + Optionally recurse into other ``attrs``-decorated classes. + + :param inst: Instance of an ``attrs``-decorated class. + :param bool recurse: Recurse into classes that are also + ``attrs``-decorated. + :param callable filter: A callable whose return code determines whether an + attribute or element is included (``True``) or dropped (``False``). Is + called with the :class:`attr.Attribute` as the first argument and the + value as the second argument. + :param callable tuple_factory: A callable to produce tuples from. For + example, to produce lists instead of tuples. + :param bool retain_collection_types: Do not convert to ``list`` + or ``dict`` when encountering an attribute which type is + ``tuple``, ``dict`` or ``set``. Only meaningful if ``recurse`` is + ``True``. + + :rtype: return type of *tuple_factory* + + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. versionadded:: 16.2.0 + """ + attrs = fields(inst.__class__) + rv = [] + retain = retain_collection_types # Very long. :/ + for a in attrs: + v = getattr(inst, a.name) + if filter is not None and not filter(a, v): + continue + if recurse is True: + if has(v.__class__): + rv.append(astuple(v, recurse=True, filter=filter, + tuple_factory=tuple_factory, + retain_collection_types=retain)) + elif isinstance(v, (tuple, list, set)): + cf = v.__class__ if retain is True else list + rv.append(cf([ + astuple(j, recurse=True, filter=filter, + tuple_factory=tuple_factory, + retain_collection_types=retain) + if has(j.__class__) else j + for j in v + ])) + elif isinstance(v, dict): + df = v.__class__ if retain is True else dict + rv.append(df( + ( + astuple( + kk, + tuple_factory=tuple_factory, + retain_collection_types=retain + ) if has(kk.__class__) else kk, + astuple( + vv, + tuple_factory=tuple_factory, + retain_collection_types=retain + ) if has(vv.__class__) else vv + ) + for kk, vv in iteritems(v))) + else: + rv.append(v) + else: + rv.append(v) + return rv if tuple_factory is list else tuple_factory(rv) + + +def has(cls): + """ + Check whether *cls* is a class with ``attrs`` attributes. + + :param type cls: Class to introspect. + :raise TypeError: If *cls* is not a class. + + :rtype: :class:`bool` + """ + return getattr(cls, "__attrs_attrs__", None) is not None + + +def assoc(inst, **changes): + """ + Copy *inst* and apply *changes*. + + :param inst: Instance of a class with ``attrs`` attributes. + :param changes: Keyword changes in the new copy. + + :return: A copy of inst with *changes* incorporated. + + :raise attr.exceptions.AttrsAttributeNotFoundError: If *attr_name* couldn't + be found on *cls*. + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. deprecated:: 17.1.0 + Use :func:`evolve` instead. + """ + import warnings + warnings.warn("assoc is deprecated and will be removed after 2018/01.", + DeprecationWarning) + new = copy.copy(inst) + attrs = fields(inst.__class__) + for k, v in iteritems(changes): + a = getattr(attrs, k, NOTHING) + if a is NOTHING: + raise AttrsAttributeNotFoundError( + "{k} is not an attrs attribute on {cl}." + .format(k=k, cl=new.__class__) + ) + _obj_setattr(new, k, v) + return new + + +def evolve(inst, **changes): + """ + Create a new instance, based on *inst* with *changes* applied. + + :param inst: Instance of a class with ``attrs`` attributes. + :param changes: Keyword changes in the new copy. + + :return: A copy of inst with *changes* incorporated. + + :raise TypeError: If *attr_name* couldn't be found in the class + ``__init__``. + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. versionadded:: 17.1.0 + """ + cls = inst.__class__ + attrs = fields(cls) + for a in attrs: + if not a.init: + continue + attr_name = a.name # To deal with private attributes. + init_name = attr_name if attr_name[0] != "_" else attr_name[1:] + if init_name not in changes: + changes[init_name] = getattr(inst, attr_name) + return cls(**changes)