Reworked the Quantity, Unit, Measurement, Group and System class to be static to ease with typing

17 files changed, 80 insertions, 89 deletions

diff --git a/pint/facets/__init__.py b/pint/facets/__init__.py
index d669b9f..7b24463 100644
--- a/pint/facets/__init__.py
+++ b/pint/facets/__init__.py
@@ -30,8 +30,8 @@
 
     class NumpyRegistry:
 
-        _quantity_class = NumpyQuantity
-        _unit_class = NumpyUnit
+        Quantity = NumpyQuantity
+        Unit = NumpyUnit
 
     This tells pint that it should use NumpyQuantity as base class for a quantity
     class that belongs to a registry that has NumpyRegistry as one of its bases.
diff --git a/pint/facets/context/registry.py b/pint/facets/context/registry.py
index 108bdf0..a36d82d 100644
--- a/pint/facets/context/registry.py
+++ b/pint/facets/context/registry.py
@@ -18,7 +18,7 @@ from ...errors import UndefinedUnitError
 from ...util import find_connected_nodes, find_shortest_path, logger
 from ..plain import PlainRegistry, UnitDefinition
 from .definitions import ContextDefinition
-from .objects import Context, ContextChain
+from . import objects
 
 # TODO: Put back annotation when possible
 # registry_cache: "RegistryCache"
@@ -50,13 +50,13 @@ class ContextRegistry(PlainRegistry):
     - Parse @context directive.
     """
 
-    Context = Context
+    Context = objects.Context
 
     def __init__(self, **kwargs: Any) -> None:
         # Map context name (string) or abbreviation to context.
-        self._contexts: dict[str, Context] = {}
+        self._contexts: dict[str, objects.Context] = {}
         # Stores active contexts.
-        self._active_ctx = ContextChain()
+        self._active_ctx = objects.ContextChain()
         # Map context chain to cache
         self._caches = {}
         # Map context chain to units override
@@ -80,7 +80,7 @@ class ContextRegistry(PlainRegistry):
         see :meth:`enable_contexts`.
         """
         if isinstance(context, ContextDefinition):
-            context = Context.from_definition(context, self.get_dimensionality)
+            context = objects.Context.from_definition(context, self.get_dimensionality)
 
         if not context.name:
             raise ValueError("Can't add unnamed context to registry")
@@ -97,7 +97,7 @@ class ContextRegistry(PlainRegistry):
                 )
             self._contexts[alias] = context
 
-    def remove_context(self, name_or_alias: str) -> Context:
+    def remove_context(self, name_or_alias: str) -> objects.Context:
         """Remove a context from the registry and return it.
 
         Notice that this methods will not disable the context;
@@ -193,7 +193,9 @@ class ContextRegistry(PlainRegistry):
         # Write into the context-specific self._units.maps[0] and self._cache.root_units
         self.define(definition)
 
-    def enable_contexts(self, *names_or_contexts: str | Context, **kwargs) -> None:
+    def enable_contexts(
+        self, *names_or_contexts: str | objects.Context, **kwargs
+    ) -> None:
         """Enable contexts provided by name or by object.
 
         Parameters
@@ -233,7 +235,7 @@ class ContextRegistry(PlainRegistry):
             ctx.checked = True
 
         # and create a new one with the new defaults.
-        contexts = tuple(Context.from_context(ctx, **kwargs) for ctx in ctxs)
+        contexts = tuple(objects.Context.from_context(ctx, **kwargs) for ctx in ctxs)
 
         # Finally we add them to the active context.
         self._active_ctx.insert_contexts(*contexts)
@@ -251,7 +253,7 @@ class ContextRegistry(PlainRegistry):
         self._switch_context_cache_and_units()
 
     @contextmanager
-    def context(self, *names, **kwargs) -> ContextManager[Context]:
+    def context(self, *names, **kwargs) -> ContextManager[objects.Context]:
         """Used as a context manager, this function enables to activate a context
         which is removed after usage.
 
diff --git a/pint/facets/dask/__init__.py b/pint/facets/dask/__init__.py
index e0821be..90c8972 100644
--- a/pint/facets/dask/__init__.py
+++ b/pint/facets/dask/__init__.py
@@ -14,7 +14,7 @@ from __future__ import annotations
 import functools
 
 from ...compat import compute, dask_array, persist, visualize
-from ..plain import PlainRegistry
+from ..plain import PlainRegistry, PlainQuantity
 
 
 def check_dask_array(f):
@@ -31,7 +31,7 @@ def check_dask_array(f):
     return wrapper
 
 
-class DaskQuantity:
+class DaskQuantity(PlainQuantity):
     # Dask.array.Array ducking
     def __dask_graph__(self):
         if isinstance(self._magnitude, dask_array.Array):
@@ -120,4 +120,4 @@ class DaskQuantity:
 
 
 class DaskRegistry(PlainRegistry):
-    _quantity_class = DaskQuantity
+    Quantity = DaskQuantity
diff --git a/pint/facets/formatting/objects.py b/pint/facets/formatting/objects.py
index fa5ca83..5df937c 100644
--- a/pint/facets/formatting/objects.py
+++ b/pint/facets/formatting/objects.py
@@ -23,8 +23,10 @@ from ...formatting import (
 )
 from ...util import UnitsContainer, iterable
 
+from ..plain import PlainQuantity, PlainUnit
 
-class FormattingQuantity:
+
+class FormattingQuantity(PlainQuantity):
     _exp_pattern = re.compile(r"([0-9]\.?[0-9]*)e(-?)\+?0*([0-9]+)")
 
     def __format__(self, spec: str) -> str:
@@ -176,7 +178,7 @@ class FormattingQuantity:
         return format(self)
 
 
-class FormattingUnit:
+class FormattingUnit(PlainUnit):
     def __str__(self):
         return format(self)
 
diff --git a/pint/facets/formatting/registry.py b/pint/facets/formatting/registry.py
index bd9c74c..c4dc373 100644
--- a/pint/facets/formatting/registry.py
+++ b/pint/facets/formatting/registry.py
@@ -13,5 +13,5 @@ from .objects import FormattingQuantity, FormattingUnit
 
 
 class FormattingRegistry(PlainRegistry):
-    _quantity_class = FormattingQuantity
-    _unit_class = FormattingUnit
+    Quantity = FormattingQuantity
+    Unit = FormattingUnit
diff --git a/pint/facets/group/registry.py b/pint/facets/group/registry.py
index c6cc06d..0d35ae0 100644
--- a/pint/facets/group/registry.py
+++ b/pint/facets/group/registry.py
@@ -15,10 +15,10 @@ from ... import errors
 if TYPE_CHECKING:
     from ..._typing import Unit
 
-from ...util import build_dependent_class, create_class_with_registry
+from ...util import create_class_with_registry
 from ..plain import PlainRegistry, UnitDefinition
 from .definitions import GroupDefinition
-from .objects import Group
+from . import objects
 
 
 class GroupRegistry(PlainRegistry):
@@ -34,19 +34,15 @@ class GroupRegistry(PlainRegistry):
     # TODO: Change this to Group: Group to specify class
     # and use introspection to get system class as a way
     # to enjoy typing goodies
-    _group_class = Group
+    Group = objects.Group
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         #: Map group name to group.
         #: :type: dict[ str | Group]
-        self._groups: dict[str, Group] = {}
+        self._groups: dict[str, objects.Group] = {}
         self._groups["root"] = self.Group("root")
 
-    def __init_subclass__(cls, **kwargs):
-        super().__init_subclass__()
-        cls.Group = build_dependent_class(cls, "Group", "_group_class")
-
     def _init_dynamic_classes(self) -> None:
         """Generate subclasses on the fly and attach them to self"""
         super()._init_dynamic_classes()
@@ -93,7 +89,7 @@ class GroupRegistry(PlainRegistry):
         except KeyError as e:
             raise errors.DefinitionSyntaxError(f"unknown dimension {e} in context")
 
-    def get_group(self, name: str, create_if_needed: bool = True) -> Group:
+    def get_group(self, name: str, create_if_needed: bool = True) -> objects.Group:
         """Return a Group.
 
         Parameters
diff --git a/pint/facets/measurement/objects.py b/pint/facets/measurement/objects.py
index aaf5750..5f3ba7a 100644
--- a/pint/facets/measurement/objects.py
+++ b/pint/facets/measurement/objects.py
@@ -18,7 +18,7 @@ from ..plain import PlainQuantity
 MISSING = object()
 
 
-class MeasurementQuantity:
+class MeasurementQuantity(PlainQuantity):
     # Measurement support
     def plus_minus(self, error, relative=False):
         if isinstance(error, self.__class__):
diff --git a/pint/facets/measurement/registry.py b/pint/facets/measurement/registry.py
index e704399..0fc4391 100644
--- a/pint/facets/measurement/registry.py
+++ b/pint/facets/measurement/registry.py
@@ -10,21 +10,15 @@
 from __future__ import annotations
 
 from ...compat import ufloat
-from ...util import build_dependent_class, create_class_with_registry
+from ...util import create_class_with_registry
 from ..plain import PlainRegistry
-from .objects import Measurement, MeasurementQuantity
+from .objects import MeasurementQuantity
+from . import objects
 
 
 class MeasurementRegistry(PlainRegistry):
-    _quantity_class = MeasurementQuantity
-    _measurement_class = Measurement
-
-    def __init_subclass__(cls, **kwargs):
-        super().__init_subclass__()
-
-        cls.Measurement = build_dependent_class(
-            cls, "Measurement", "_measurement_class"
-        )
+    Quantity = MeasurementQuantity
+    Measurement = objects.Measurement
 
     def _init_dynamic_classes(self) -> None:
         """Generate subclasses on the fly and attach them to self"""
diff --git a/pint/facets/nonmultiplicative/objects.py b/pint/facets/nonmultiplicative/objects.py
index a0456de..7f9064d 100644
--- a/pint/facets/nonmultiplicative/objects.py
+++ b/pint/facets/nonmultiplicative/objects.py
@@ -8,8 +8,10 @@
 
 from __future__ import annotations
 
+from ..plain import PlainQuantity
 
-class NonMultiplicativeQuantity:
+
+class NonMultiplicativeQuantity(PlainQuantity):
     @property
     def _is_multiplicative(self) -> bool:
         """Check if the PlainQuantity object has only multiplicative units."""
diff --git a/pint/facets/nonmultiplicative/registry.py b/pint/facets/nonmultiplicative/registry.py
index 9bbc1aa..8bc04db 100644
--- a/pint/facets/nonmultiplicative/registry.py
+++ b/pint/facets/nonmultiplicative/registry.py
@@ -35,7 +35,7 @@ class NonMultiplicativeRegistry(PlainRegistry):
 
     """
 
-    _quantity_class = NonMultiplicativeQuantity
+    Quantity = NonMultiplicativeQuantity
 
     def __init__(
         self,
diff --git a/pint/facets/numpy/quantity.py b/pint/facets/numpy/quantity.py
index 410654a..131983c 100644
--- a/pint/facets/numpy/quantity.py
+++ b/pint/facets/numpy/quantity.py
@@ -13,6 +13,8 @@ import math
 import warnings
 from typing import Any
 
+from ..plain import PlainQuantity
+
 from ..._typing import Shape, _MagnitudeType
 from ...compat import _to_magnitude, np
 from ...errors import DimensionalityError, PintTypeError, UnitStrippedWarning
@@ -40,7 +42,7 @@ def method_wraps(numpy_func):
     return wrapper
 
 
-class NumpyQuantity:
+class NumpyQuantity(PlainQuantity):
     """ """
 
     # NumPy function/ufunc support
diff --git a/pint/facets/numpy/registry.py b/pint/facets/numpy/registry.py
index fa4768f..11d57f3 100644
--- a/pint/facets/numpy/registry.py
+++ b/pint/facets/numpy/registry.py
@@ -15,5 +15,5 @@ from .unit import NumpyUnit
 
 
 class NumpyRegistry(PlainRegistry):
-    _quantity_class = NumpyQuantity
-    _unit_class = NumpyUnit
+    Quantity = NumpyQuantity
+    Unit = NumpyUnit
diff --git a/pint/facets/numpy/unit.py b/pint/facets/numpy/unit.py
index 21b3594..d6bf140 100644
--- a/pint/facets/numpy/unit.py
+++ b/pint/facets/numpy/unit.py
@@ -9,9 +9,10 @@
 from __future__ import annotations
 
 from ...compat import is_upcast_type
+from ..plain import PlainUnit
 
 
-class NumpyUnit:
+class NumpyUnit(PlainUnit):
     __array_priority__ = 17
 
     def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
index a35e508..d3baff4 100644
--- a/pint/facets/plain/registry.py
+++ b/pint/facets/plain/registry.py
@@ -43,7 +43,6 @@ from ...util import UnitsContainer
 from ...util import UnitsContainer as UnitsContainerT
 from ...util import (
     _is_dim,
-    build_dependent_class,
     create_class_with_registry,
     getattr_maybe_raise,
     logger,
@@ -177,8 +176,8 @@ class PlainRegistry(metaclass=RegistryMeta):
 
     _diskcache = None
 
-    _quantity_class = PlainQuantity
-    _unit_class = PlainUnit
+    Quantity = PlainQuantity
+    Unit = PlainUnit
 
     _def_parser = None
 
@@ -278,13 +277,6 @@ class PlainRegistry(metaclass=RegistryMeta):
 
         self._initialized = False
 
-    def __init_subclass__(cls, **kwargs):
-        super().__init_subclass__()
-        cls.Unit: Unit = build_dependent_class(cls, "Unit", "_unit_class")
-        cls.Quantity: Quantity = build_dependent_class(
-            cls, "Quantity", "_quantity_class"
-        )
-
     def _init_dynamic_classes(self) -> None:
         """Generate subclasses on the fly and attach them to self"""
 
diff --git a/pint/facets/system/registry.py b/pint/facets/system/registry.py
index accccb2..6e0878e 100644
--- a/pint/facets/system/registry.py
+++ b/pint/facets/system/registry.py
@@ -19,13 +19,13 @@ if TYPE_CHECKING:
 from ..._typing import UnitLike
 from ...util import UnitsContainer as UnitsContainerT
 from ...util import (
-    build_dependent_class,
     create_class_with_registry,
     to_units_container,
 )
 from ..group import GroupRegistry
 from .definitions import SystemDefinition
 from .objects import Lister, System
+from . import objects
 
 
 class SystemRegistry(GroupRegistry):
@@ -46,7 +46,7 @@ class SystemRegistry(GroupRegistry):
     # TODO: Change this to System: System to specify class
     # and use introspection to get system class as a way
     # to enjoy typing goodies
-    _system_class = System
+    System = objects.System
 
     def __init__(self, system=None, **kwargs):
         super().__init__(**kwargs)
@@ -60,10 +60,6 @@ class SystemRegistry(GroupRegistry):
 
         self._default_system = system
 
-    def __init_subclass__(cls, **kwargs):
-        super().__init_subclass__()
-        cls.System = build_dependent_class(cls, "System", "_system_class")
-
     def _init_dynamic_classes(self) -> None:
         """Generate subclasses on the fly and attach them to self"""
         super()._init_dynamic_classes()
diff --git a/pint/registry.py b/pint/registry.py
index 29d5c89..474eb77 100644
--- a/pint/registry.py
+++ b/pint/registry.py
@@ -27,6 +27,35 @@ from .facets import (
 from .util import logger, pi_theorem
 
 
+# To build the Quantity and Unit classes
+# we follow the UnitRegistry bases
+# but
+
+
+class Quantity(
+    # SystemRegistry.Quantity,
+    # ContextRegistry.Quantity,
+    DaskRegistry.Quantity,
+    NumpyRegistry.Quantity,
+    MeasurementRegistry.Quantity,
+    FormattingRegistry.Quantity,
+    NonMultiplicativeRegistry.Quantity,
+):
+    pass
+
+
+class Unit(
+    # SystemRegistry.Unit,
+    # ContextRegistry.Unit,
+    # DaskRegistry.Unit,
+    NumpyRegistry.Unit,
+    # MeasurementRegistry.Unit,
+    FormattingRegistry.Unit,
+    NonMultiplicativeRegistry.Unit,
+):
+    pass
+
+
 class UnitRegistry(
     SystemRegistry,
     ContextRegistry,
@@ -72,6 +101,9 @@ class UnitRegistry(
         If None, the cache is disabled. (default)
     """
 
+    Quantity = Quantity
+    Unit = Unit
+
     def __init__(
         self,
         filename="",
diff --git a/pint/util.py b/pint/util.py
index a99d314..28710e7 100644
--- a/pint/util.py
+++ b/pint/util.py
@@ -10,8 +10,6 @@
 
 from __future__ import annotations
 
-import functools
-import inspect
 import logging
 import math
 import operator
@@ -1010,32 +1008,6 @@ def sized(y) -> bool:
     return True
 
 
-@functools.cache
-def _build_type(class_name: str, bases):
-    return type(class_name, bases, {})
-
-
-def build_dependent_class(registry_class, class_name: str, attribute_name: str) -> type:
-    """Creates a class specifically for the given registry that
-    subclass all the classes named by the registry bases in a
-    specific attribute
-
-    1. List the 'attribute_name' attribute for each of the bases of the registry class.
-    2. Use this list as bases for the new class
-    3. Add the provided registry as the class registry.
-
-    """
-    bases = (
-        getattr(base, attribute_name)
-        for base in inspect.getmro(registry_class)
-        if attribute_name in base.__dict__
-    )
-    bases = tuple(dict.fromkeys(bases, None).keys())
-    if len(bases) == 1 and bases[0].__name__ == class_name:
-        return bases[0]
-    return _build_type(class_name, bases)
-
-
 def create_class_with_registry(registry, base_class) -> type:
     """Create new class inheriting from base_class and
     filling _REGISTRY class attribute with an actual instanced registry.