from __future__ import annotations
from dataclasses import dataclass
from typing import Annotated, Any
[docs]
def annotation_encode(obj: Any) -> Any:
"""Encodes *obj* for :obj:`~typing.Annotated`.
Annotated params must be hashable. This function converts dicts and lists
into hashable alternatives (tuples and frozensets).
For example:
.. code-block:: python
foo = Annotated(Bar, annotation_encode({"a": [1, 2, 3]}))
*obj* must not contain tuples or frozensets, or unhashable data besides
dicts and lists.
"""
if isinstance(obj, (tuple, list)):
return tuple(annotation_encode(e) for e in obj)
if isinstance(obj, dict):
return frozenset(
(annotation_encode(k), annotation_encode(v)) for k, v in obj.items()
)
return obj
[docs]
def annotation_decode(obj: Any) -> Any:
"""Converts a result of :func:`annotation_encode` back to original form."""
if isinstance(obj, tuple):
return [annotation_decode(o) for o in obj]
if isinstance(obj, frozenset):
return {annotation_decode(k): annotation_decode(v) for k, v in obj}
return obj
[docs]
@dataclass
class AnnotatedInstance:
"""Wrapper for instances of annotated dependencies.
It is used when both the dependency value and the dependency annotation are
needed.
:param result: The wrapped dependency instance.
:type result: Any
:param metadata: The copy of the annotation.
:type metadata: Tuple[Any, ...]
"""
result: Any
metadata: tuple[Any, ...]
def get_annotated_cls(self) -> Annotated[Any, ...]:
"""Returns a re-created :class:`typing.Annotated` type."""
return Annotated[(type(self.result), *self.metadata)]
__all__: list[str] = [] # Prefer imports from web_poet.__init__.py