Source code for betty.serde.dump

"""
Provide a serialization API.
"""

from __future__ import annotations

from typing import TypeVar, Sequence, Mapping, overload, Literal, TypeAlias, Any

from betty.typing import Void

#: The Python types that define a serialized dump.
DumpType: TypeAlias = bool | int | float | str | None | list["Dump"] | dict[str, "Dump"]
_DumpTypeT = TypeVar("_DumpTypeT", bound=DumpType)

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

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

#: A dump which is a list whose values are serialized dumps.
ListDump: TypeAlias = list[_DumpT]

#: A dump which is a dictionary whose keys are strings and values are serialized dumps.
DictDump: TypeAlias = dict[str, _DumpT]

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

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

_MinimizableDump: TypeAlias = (
    VoidableDump | VoidableListDump[_VoidableDumpU] | VoidableDictDump[_VoidableDumpU]
)


@overload
def minimize(
    dump: _MinimizableDump[VoidableDump], voidable: Literal[True] = True
) -> VoidableDump:
    pass  # pragma: no cover


@overload
def minimize(dump: _MinimizableDump[VoidableDump], voidable: Literal[False]) -> Dump:
    pass  # pragma: no cover


[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, (Sequence, Mapping)) and not isinstance(dump, str): if isinstance(dump, Sequence): 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, Mapping): 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: DictDump[Dump], key: str, default_type: type[dict[Any, Any]] ) -> DictDump[Dump]: pass # pragma: no cover @overload def dump_default( dump: DictDump[Dump], key: str, default_type: type[list[Any]] ) -> ListDump[Dump]: pass # pragma: no cover
[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: """ Instances can be dumped to serializable data. """
[docs] def dump(self) -> VoidableDump: """ Dump this instance to a portable format. """ raise NotImplementedError(repr(self))