Source code for swh.model.collections

# Copyright (C) 2020-2023 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

from __future__ import annotations

"""Utility data structures."""

from import Mapping
import copy
from typing import Dict, Generic, Iterable, Optional, Tuple, TypeVar, Union

KT = TypeVar("KT")
VT = TypeVar("VT")

[docs] class ImmutableDict(Mapping, Generic[KT, VT]): """A frozen dictionary. This class behaves like a dictionary, but internally stores objects in a tuple, so it is both immutable and hashable.""" _data: Dict[KT, VT] def __init__( self, data: Union[Iterable[Tuple[KT, VT]], ImmutableDict[KT, VT], Dict[KT, VT]] = {}, ): if isinstance(data, dict): self._data = data elif isinstance(data, ImmutableDict): self._data = data._data else: self._data = {k: v for k, v in data} @property def data(self): return tuple(self._data.items()) def __repr__(self): return f"ImmutableDict({dict(!r})" def __getitem__(self, key): return self._data[key] def __iter__(self): for k, v in yield k def __len__(self): return len(self._data)
[docs] def items(self): yield from
def __hash__(self): return hash(tuple(sorted(
[docs] def copy_pop(self, popped_key) -> Tuple[Optional[VT], ImmutableDict[KT, VT]]: """Returns a copy of this ImmutableDict without the given key, as well as the value associated to the key.""" new_items = copy.deepcopy(self._data) popped_value: Optional[VT] = new_items.pop(popped_key, None) return (popped_value, ImmutableDict(new_items))