Remove attrs

pyproject.toml

@@ -88,7 +88,8 @@ extra-dependencies = [
     "lmdb",
     "zstandard",
     "crc32c",
-    "pytest-asyncio"
+    "pytest-asyncio",
+    "typing_extensions"
 ]
 
 [tool.hatch.envs.test.scripts]

src/zarr/v3/__init__.py

@@ -4,9 +4,10 @@
 
 import zarr.v3.codecs  # noqa: F401
 from zarr.v3.array import Array  # noqa: F401
-from zarr.v3.array_v2 import ArrayV2  # noqa: F401
+from zarr.v3.array_v2 import ArrayV2
+from zarr.v3.common import RuntimeConfiguration  # noqa: F401
 from zarr.v3.group import Group  # noqa: F401
-from zarr.v3.metadata import RuntimeConfiguration, runtime_configuration  # noqa: F401
+from zarr.v3.metadata import runtime_configuration  # noqa: F401
 from zarr.v3.store import (  # noqa: F401
     StoreLike,
     make_store_path,

src/zarr/v3/abc/codec.py

@@ -1,45 +1,35 @@
 from __future__ import annotations
 
-from abc import abstractmethod, ABC
-from typing import TYPE_CHECKING, Optional, Type
+from abc import abstractmethod
+from typing import TYPE_CHECKING, Optional
 
 import numpy as np
+from zarr.v3.abc.metadata import Metadata
 
-from zarr.v3.common import BytesLike, SliceSelection
+from zarr.v3.common import ArraySpec
 from zarr.v3.store import StorePath
 
 
 if TYPE_CHECKING:
+    from typing_extensions import Self
+    from zarr.v3.common import BytesLike, SliceSelection
     from zarr.v3.metadata import (
-        ArraySpec,
         ArrayMetadata,
-        DataType,
-        CodecMetadata,
         RuntimeConfiguration,
     )
 
 
-class Codec(ABC):
+class Codec(Metadata):
     is_fixed_size: bool
 
-    @classmethod
-    @abstractmethod
-    def get_metadata_class(cls) -> Type[CodecMetadata]:
-        pass
-
-    @classmethod
-    @abstractmethod
-    def from_metadata(cls, codec_metadata: CodecMetadata) -> Codec:
-        pass
-
     @abstractmethod
     def compute_encoded_size(self, input_byte_length: int, chunk_spec: ArraySpec) -> int:
         pass
 
     def resolve_metadata(self, chunk_spec: ArraySpec) -> ArraySpec:
         return chunk_spec
 
-    def evolve(self, *, ndim: int, data_type: DataType) -> Codec:
+    def evolve(self, array_spec: ArraySpec) -> Self:
         return self
 
     def validate(self, array_metadata: ArrayMetadata) -> None:

src/zarr/v3/abc/metadata.py

@@ -0,0 +1,44 @@
+from __future__ import annotations
+from typing import TYPE_CHECKING, Sequence
+
+if TYPE_CHECKING:
+    from typing import Dict, Any
+    from typing_extensions import Self
+
+from dataclasses import fields
+
+from zarr.v3.common import JSON
+
+
+class Metadata:
+    def to_dict(self) -> Dict[str, Any]:
+        """
+        Recursively serialize this model to a dictionary.
+        This method inspects the fields of self and calls `x.to_dict()` for any fields that
+        are instances of `Metadata`. Sequences of `Metadata` are similarly recursed into, and
+        the output of that recursion is collected in a list.
+        """
+        ...
+        out_dict = {}
+        for field in fields(self):
+            key = field.name
+            value = getattr(self, key)
+            if isinstance(value, Metadata):
+                out_dict[field.name] = getattr(self, field.name).to_dict()
+            elif isinstance(value, str):
+                out_dict[key] = value
+            elif isinstance(value, Sequence):
+                out_dict[key] = [v.to_dict() if isinstance(v, Metadata) else v for v in value]
+            else:
+                out_dict[key] = value
+
+        return out_dict
+
+    @classmethod
+    def from_dict(cls, data: Dict[str, JSON]) -> Self:
+        """
+        Create an instance of the model from a dictionary
+        """
+        ...
+
+        return cls(**data)