Source code for betty.serde.dump

"""
Provide a serialization API.
"""

from __future__ import annotations

from abc import ABC, abstractmethod
from collections.abc import MutableMapping, MutableSequence
from typing import TypeVar, overload, Literal, TypeAlias

from betty.typing import Void

#: A serialized dump.
Dump: TypeAlias = (
    bool
    | int
    | float
    | str
    | None
    | MutableSequence["Dump"]
    | MutableMapping[str, "Dump"]
)
_DumpT = TypeVar("_DumpT", bound=Dump)

#: A serialized dump that may be :py:class:`betty.typing.Void`.
VoidableDump: TypeAlias = Dump | type[Void]
_VoidableDumpT = TypeVar("_VoidableDumpT", bound=VoidableDump)

#: A dump which is a sequence whose values are serialized dumps.
DumpSequence: TypeAlias = MutableSequence[_DumpT]

#: A dump which is a mapping whose keys are strings and values are serialized dumps.
DumpMapping: TypeAlias = MutableMapping[str, _DumpT]

#: A dump which is a sequence whose values are serialized dumps, or that may be :py:class:`betty.serde.dump.Void`
VoidableDumpSequence: TypeAlias = MutableSequence[_VoidableDumpT]

#: A dump which is a mapping whose keys are strings and values are serialized dumps, or that may be :py:class:`betty.serde.dump.Void`
VoidableDumpMapping: TypeAlias = MutableMapping[str, _VoidableDumpT]

_MinimizableDump: TypeAlias = (
    VoidableDump
    | VoidableDumpSequence[_VoidableDumpT]
    | VoidableDumpMapping[_VoidableDumpT]
)


@overload
def minimize(
    dump: _MinimizableDump[VoidableDump], voidable: Literal[True] = True
) -> VoidableDump:
    pass


@overload
def minimize(dump: _MinimizableDump[VoidableDump], voidable: Literal[False]) -> Dump:
    pass


[docs] def minimize( dump: _MinimizableDump[VoidableDump], voidable: bool = True ) -> VoidableDump: """ Minimize a configuration dump by removing any Void configurationfrom sequences and mappings. """ if isinstance(dump, (MutableSequence, MutableMapping)): if isinstance(dump, MutableSequence): dump = [value for value in dump if value is not Void] for key in reversed(range(len(dump))): if dump[key] is Void: del dump[key] if isinstance(dump, MutableMapping): dump = {key: value for key, value in dump.items() if value is not Void} if len(dump) or not voidable: return dump # type: ignore[return-value] return Void return dump
[docs] def void_none(value: VoidableDump) -> VoidableDump: """ Passthrough a value, but convert Void to None. """ return Void if value is None else value
[docs] def none_void(value: VoidableDump) -> VoidableDump: """ Passthrough a value, but convert None to Void. """ return None if value is Void else value
@overload def dump_default( dump: DumpMapping[Dump], key: str, default_type: type[DumpMapping[Dump]] ) -> DumpMapping[Dump]: pass @overload def dump_default( dump: DumpMapping[Dump], key: str, default_type: type[DumpSequence[Dump]] ) -> DumpSequence[Dump]: pass
[docs] def dump_default(dump, key, default_type): """ Add a key and value to a dump, if the key does not exist yet. """ try: assert isinstance(dump[key], default_type) except KeyError: dump[key] = default_type() return dump[key] # type: ignore[return-value]
[docs] class Dumpable(ABC): """ Instances can be dumped to serializable data. """
[docs] @abstractmethod def dump(self) -> VoidableDump: """ Dump this instance to a portable format. """ pass