# -------------------------------------------------------------------------------------- # Copyright (c) 2021-2025, Nucleic Development Team. # # Distributed under the terms of the Modified BSD License. # # The full license is in the file LICENSE, distributed with this software. # -------------------------------------------------------------------------------------- import collections.abc import sys from collections import defaultdict from typing import Any, ClassVar, Final, Literal, MutableMapping, Type from ..catom import Member, SetAttr from ..dict import DefaultDict, Dict as ADict from ..enum import Enum from ..instance import Instance from ..list import List as AList from ..scalars import Bool, Bytes, Callable as ACallable, Float, Int, Str, Value from ..set import Set as ASet from ..subclass import Subclass from ..tuple import FixedTuple, Tuple as ATuple from ..typed import Typed from ..typing_utils import extract_types, get_args, get_origin, is_optional from .member_modifiers import set_default _NO_DEFAULT = object() _TYPE_TO_MEMBER = { bool: Bool, int: Int, float: Float, str: Str, bytes: Bytes, list: AList, dict: ADict, defaultdict: DefaultDict, set: ASet, tuple: ATuple, collections.abc.Callable: ACallable, } def generate_member_from_type_or_generic( type_generic: Any, default: Any, annotate_type_containers: int ) -> Member: """Generate a member from a type or generic alias.""" types: tuple[type, ...] origin = get_origin(type_generic) # For final we create the member corresponding to the inner type and set # the access mode as ReadOnly if origin is Final: member = generate_member_from_type_or_generic( get_args(type_generic)[0], default, annotate_type_containers ) member.set_setattr_mode(SetAttr.ReadOnly, None) return member # Here we special case Literal to generate an Enum member. elif origin is Literal: types = () else: types = extract_types(type_generic) parameters = get_args(type_generic) m_kwargs = {} m_cls: Type[Member] if any( isinstance(t, type) and issubclass(t, Member) for t in types ) and not isinstance(default, Member): raise ValueError( "Member subclasses cannot be used as annotations without " "specifying a default value for the attribute." ) elif object in types or Any in types: m_cls = Value parameters = () # We are dealing with a Literal, so use an Enum member elif not types: m_cls = Enum if default is not _NO_DEFAULT: if default not in parameters: raise ValueError( f"Default value {default} does not appear in Literal: {parameters}" ) # Make the default value the first in the enum arguments. p = list(parameters) p.pop(p.index(default)) parameters = (default, *p) default = _NO_DEFAULT # Int, Float, Str, Bytes, List, Dict, Set, Tuple, Bool, Callable elif len(types) == 1 and types[0] in _TYPE_TO_MEMBER: t = types[0] m_cls = _TYPE_TO_MEMBER[t] if annotate_type_containers and t in ( list, dict, collections.defaultdict, set, tuple, ): if t is tuple: if (...) in parameters: parameters = (parameters[0],) else: m_cls = FixedTuple parameters = tuple( generate_member_from_type_or_generic( t, _NO_DEFAULT, annotate_type_containers - 1 ) if t not in (Any, object) else Value() for t in parameters ) else: parameters = () # The value was annotated with Type[T] so we use a subclass elif all(t is type for t in types): m_cls = Subclass assert len(parameters) == 1 parameters = extract_types(parameters[0]) else: # Only a metaclass can implement __instancecheck__ so we check for an # implementation differing from type.__instancecheck__ and use Instance # if we find one and otherwise Typed. opt, filtered_types = is_optional(types) if ( len(filtered_types) == 1 and type(filtered_types[0]).__instancecheck__ is type.__instancecheck__ ): m_cls = Typed else: m_cls = Instance parameters = (filtered_types,) m_kwargs["optional"] = opt if opt and default not in (_NO_DEFAULT, None): raise ValueError( "Members requiring Instance(optional=True) cannot have " "a non-None default value." ) elif not opt and default is not _NO_DEFAULT: raise ValueError("Members requiring Instance cannot have a default value.") # Instance does not have a default keyword so turn a None default into the # equivalent no default. default = _NO_DEFAULT if default is not _NO_DEFAULT: m_kwargs["default"] = default return m_cls(*parameters, **m_kwargs) def generate_members_from_cls_namespace( cls_name: str, namespace: MutableMapping[str, Any], annotate_type_containers: int ) -> None: """Generate the member corresponding to a type annotation.""" # On 3.14 use annotationlib # cf https://docs.python.org/3.14/library/annotationlib.html if sys.version_info >= (3, 14): import annotationlib if "__annotations__" in namespace: annotations = namespace["__annotations__"] else: annotate = annotationlib.get_annotate_from_class_namespace(namespace) if annotate is None: annotations = {} else: annotations = annotationlib.call_annotate_function( annotate, format=annotationlib.Format.FORWARDREF ) else: annotations = namespace.get("__annotations__", {}) # XXX handle forward refs for name, ann in annotations.items(): default = namespace.get(name, _NO_DEFAULT) # We skip field for which a member was already provided or annotations # corresponding to class variables. if isinstance(default, (Member, set_default)): # Allow string annotations for members if isinstance(ann, str): continue types = extract_types(ann) if len(types) != 1 or not issubclass(types[0], Member): raise TypeError( f"Field '{name}' of '{cls_name}' is assigned a Member-like value " "but its annotation is not Member compatible" ) continue # We also skip fields annotated as class variables. elif getattr(ann, "__origin__", None) is ClassVar: continue try: namespace[name] = generate_member_from_type_or_generic( ann, default, annotate_type_containers ) except ValueError as e: raise ValueError( "Encountered an issue when generating a member for field " f"'{name}' of '{cls_name}'." ) from e