| from __future__ import annotations |
|
|
| from typing import Any |
|
|
| from . import NODEFAULT, Struct, field |
| from ._core import ( |
| Factory as _Factory, |
| StructConfig, |
| asdict, |
| astuple, |
| replace, |
| force_setattr, |
| ) |
| from ._utils import get_class_annotations as _get_class_annotations |
|
|
| __all__ = ( |
| "FieldInfo", |
| "StructConfig", |
| "asdict", |
| "astuple", |
| "fields", |
| "force_setattr", |
| "replace", |
| ) |
|
|
|
|
| def __dir__(): |
| return __all__ |
|
|
|
|
| class FieldInfo(Struct): |
| """A record describing a field in a struct type. |
| |
| Parameters |
| ---------- |
| name: str |
| The field name as seen by Python code (e.g. ``field_one``). |
| encode_name: str |
| The name used when encoding/decoding the field. This may differ if |
| the field is renamed (e.g. ``fieldOne``). |
| type: Any |
| The full field type annotation. |
| default: Any, optional |
| A default value for the field. Will be `NODEFAULT` if no default value |
| is set. |
| default_factory: Any, optional |
| A callable that creates a default value for the field. Will be |
| `NODEFAULT` if no ``default_factory`` is set. |
| """ |
|
|
| name: str |
| encode_name: str |
| type: Any |
| default: Any = field(default_factory=lambda: NODEFAULT) |
| default_factory: Any = field(default_factory=lambda: NODEFAULT) |
|
|
| @property |
| def required(self) -> bool: |
| """A helper for checking whether a field is required""" |
| return self.default is NODEFAULT and self.default_factory is NODEFAULT |
|
|
|
|
| def fields(type_or_instance: Struct | type[Struct]) -> tuple[FieldInfo]: |
| """Get information about the fields in a Struct. |
| |
| Parameters |
| ---------- |
| type_or_instance: |
| A struct type or instance. |
| |
| Returns |
| ------- |
| tuple[FieldInfo] |
| """ |
| if isinstance(type_or_instance, Struct): |
| annotated_cls = cls = type(type_or_instance) |
| else: |
| annotated_cls = type_or_instance |
| cls = getattr(type_or_instance, "__origin__", type_or_instance) |
| if not (isinstance(cls, type) and issubclass(cls, Struct)): |
| raise TypeError("Must be called with a struct type or instance") |
|
|
| hints = _get_class_annotations(annotated_cls) |
| npos = len(cls.__struct_fields__) - len(cls.__struct_defaults__) |
| fields = [] |
| for name, encode_name, default_obj in zip( |
| cls.__struct_fields__, |
| cls.__struct_encode_fields__, |
| (NODEFAULT,) * npos + cls.__struct_defaults__, |
| ): |
| default = default_factory = NODEFAULT |
| if isinstance(default_obj, _Factory): |
| default_factory = default_obj.factory |
| elif default_obj is not NODEFAULT: |
| default = default_obj |
|
|
| field = FieldInfo( |
| name=name, |
| encode_name=encode_name, |
| type=hints[name], |
| default=default, |
| default_factory=default_factory, |
| ) |
| fields.append(field) |
|
|
| return tuple(fields) |
|
|
