support recursive types and unions of containers, improve error messages (#4)

Author: epwalsh

CHANGELOG.md

@@ -7,6 +7,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Added
+
+- Added support for decoding recursive types, i.e. classes that take arguments which are or contain instances of the same class.
+
+### Changed
+
+- `decode()` failures now raise a `DecodeError`. This is a subclass of `TypeError`, which keeps things backwards compatible
+  for the most part, except when unknown top-level fields are encountered, which used to raise an `AttributeError`.
+
+### Fixed
+
+- Fixed decoding a union of different dataclass types, and unions of collections.
+- Improved decoding error messages.
+
 ## [v0.2.12](https://github.com/epwalsh/dataclass-extensions/releases/tag/v0.2.12) - 2026-02-11
 
 ### Fixed

pyproject.toml

@@ -12,7 +12,9 @@ authors = [
 ]
 requires-python = ">=3.10"
 license = { file = "LICENSE" }
-dependencies = []
+dependencies = [
+    "typing_extensions",
+]
 
 [project.urls]
 Homepage = "https://github.com/epwalsh/dataclass-extensions"

src/dataclass_extensions/__init__.py

@@ -1,4 +1,4 @@
-from .decode import decode
+from .decode import DecodeError, decode
 from .encode import encode
 from .registrable import Registrable
 from .types import Dataclass
@@ -7,6 +7,7 @@
 __all__ = [
     "Dataclass",
     "Registrable",
+    "DecodeError",
     "required_field",
     "encode",
     "decode",