%PDF-
%PDF-
Mini Shell
Mini Shell
from __future__ import annotations
import sys
from functools import partial
from typing import Any, Callable, Tuple, Type, cast
from attr import fields, has, resolve_types
from cattr import GenConverter
from cattr.gen import (
AttributeOverride,
make_dict_structure_fn,
make_dict_unstructure_fn,
override,
)
from fontTools.misc.transform import Transform
is_py37 = sys.version_info[:2] == (3, 7)
if is_py37:
def get_origin(cl: Type[Any]) -> Any:
return getattr(cl, "__origin__", None)
else:
from typing import get_origin # type: ignore
__all__ = [
"register_hooks",
"structure",
"unstructure",
]
def is_ufoLib2_class(cls: Type[Any]) -> bool:
mod: str = getattr(cls, "__module__", "")
return mod.split(".")[0] == "ufoLib2"
def is_ufoLib2_attrs_class(cls: Type[Any]) -> bool:
return is_ufoLib2_class(cls) and (has(cls) or has(get_origin(cls)))
def is_ufoLib2_class_with_custom_unstructure(cls: Type[Any]) -> bool:
return is_ufoLib2_class(cls) and hasattr(cls, "_unstructure")
def is_ufoLib2_class_with_custom_structure(cls: Type[Any]) -> bool:
return is_ufoLib2_class(cls) and hasattr(cls, "_structure")
def register_hooks(conv: GenConverter, allow_bytes: bool = True) -> None:
def attrs_hook_factory(
cls: Type[Any], gen_fn: Callable[..., Callable[[Any], Any]], structuring: bool
) -> Callable[[Any], Any]:
base = get_origin(cls)
if base is None:
base = cls
attribs = fields(base)
# PEP563 postponed annotations need resolving as we check Attribute.type below
resolve_types(base)
kwargs: dict[str, bool | AttributeOverride] = {}
if structuring:
kwargs["_cattrs_forbid_extra_keys"] = conv.forbid_extra_keys
kwargs["_cattrs_prefer_attrib_converters"] = conv._prefer_attrib_converters
else:
kwargs["_cattrs_omit_if_default"] = conv.omit_if_default
for a in attribs:
if a.type in conv.type_overrides:
# cattrs' gen_(un)structure_attrs_fromdict (used by default for attrs
# classes that don't have a custom hook registered) check for any
# type_overrides (Dict[Type, AttributeOverride]); they allow a custom
# converter to omit specific attributes of given type e.g.:
# >>> conv = GenConverter(type_overrides={Image: override(omit=True)})
attrib_override = conv.type_overrides[a.type]
else:
# by default, we omit all Optional attributes (i.e. with None default),
# overriding a Converter's global 'omit_if_default' option. Specific
# attibutes can still define their own 'omit_if_default' behavior in
# the Attribute.metadata dict.
attrib_override = override(
omit_if_default=a.metadata.get(
"omit_if_default", a.default is None or None
),
rename=a.metadata.get(
"rename_attr", a.name[1:] if a.name[0] == "_" else None
),
omit=not a.init,
)
kwargs[a.name] = attrib_override
return gen_fn(cls, conv, **kwargs)
def custom_unstructure_hook_factory(cls: Type[Any]) -> Callable[[Any], Any]:
return partial(cls._unstructure, converter=conv)
def custom_structure_hook_factory(cls: Type[Any]) -> Callable[[Any], Any]:
return partial(cls._structure, converter=conv)
def unstructure_transform(t: Transform) -> Tuple[float]:
return cast(Tuple[float], tuple(t))
conv.register_unstructure_hook_factory(
is_ufoLib2_attrs_class,
partial(attrs_hook_factory, gen_fn=make_dict_unstructure_fn, structuring=False),
)
conv.register_unstructure_hook_factory(
is_ufoLib2_class_with_custom_unstructure,
custom_unstructure_hook_factory,
)
conv.register_unstructure_hook(
cast(Type[Transform], Transform), unstructure_transform
)
conv.register_structure_hook_factory(
is_ufoLib2_attrs_class,
partial(attrs_hook_factory, gen_fn=make_dict_structure_fn, structuring=True),
)
conv.register_structure_hook_factory(
is_ufoLib2_class_with_custom_structure,
custom_structure_hook_factory,
)
if not allow_bytes:
from base64 import b64decode, b64encode
def unstructure_bytes(v: bytes) -> str:
return (b64encode(v) if v else b"").decode("utf8")
def structure_bytes(v: str, _: Any) -> bytes:
return b64decode(v)
conv.register_unstructure_hook(bytes, unstructure_bytes)
conv.register_structure_hook(bytes, structure_bytes)
default_converter = GenConverter(
omit_if_default=True,
forbid_extra_keys=True,
prefer_attrib_converters=False,
)
register_hooks(default_converter, allow_bytes=False)
structure = default_converter.structure
unstructure = default_converter.unstructure
Zerion Mini Shell 1.0