Roadmap

This document outlines the implementation status of various Python features for CSnakes.

Typing Constructs

Note that any constructs which are not available will be typed as PyObject. They still work, but the source generator won't generate the automatic marshal and unmarshal code for them. This means that you will have to manually marshal and unmarshal these types in your C# code.

Construct (link)	Supported in CSnakes	Notes	Summary
Any	Yes		Special type that matches any type.
Union	No	No equivalent construct in C#, possibly could use overloads	Accepts one of several types.
Optional	Yes		Shorthand for a type or None.
Literal	No	Possible with enums	Restricts a value to specific literal values.
Final	No	Would be simple to implement, but not used on function signatures	Indicates a name cannot be reassigned.
ClassVar	No	Would be simple, but not used on function signatures	Marks a variable as a class variable.
Generic	No	Relies on class reflection	Base class for generic types.
TypeVar			Defines a generic type variable.
Callable	No	Callables would have to by Python objects, not C# functions	Represents a callable object (e.g., function).
Tuple	Yes		Fixed-length, ordered collection of types.
List	Yes		Variable-length, ordered collection of types.
Dict	Yes		Dictionary mapping keys to values.
Set		Usage of sets is quite niche, if you would like this feature please request it.	Unordered collection of unique elements.
FrozenSet		As above	Immutable set.
Deque	No		Double-ended queue.
DefaultDict	No	Use Mapping type instead	Dictionary with a default value for missing keys.
Counter	No	Use Mapping type instead	Dict subclass for counting hashable objects.
ChainMap			Groups multiple dicts into a single view.
Type			Indicates a type object.
NewType	No	Not useful for reflection	Creates distinct types for type checking.
NoReturn	No	Very unlikely to be used, but could be reflected to void	Indicates a function never returns.
Self	No	Will be used in class reflection	Refers to the instance type in class bodies.
Concatenate	No	Very hard to achieve in C#	Used for advanced typing of callable signatures.
ParamSpec			Used for typing callable parameter lists.
Protocol			Defines structural subtyping (static duck typing).
runtime_checkable			Decorator to allow isinstance checks with Protocols.
Annotated			Adds context-specific metadata to types.
ForwardRef			Internal type for forward references.
overload	No	Issue	Allows function overloading for type checkers.

Collections ABC

Construct (link)	Supported in CSnakes	Notes	Summary
Collection (collections.abc)	No		Sized iterable container with contains.
Container (collections.abc)	No		Supports membership test using contains.
Hashable (collections.abc)	No		Objects with a hash value.
ItemsView (collections.abc)	No		View on dictionary's items.
Iterable (collections.abc)	No	Issue	Object capable of returning its members one at a time.
Iterator (collections.abc)	No		Produces items from an iterable.
Generator (collections.abc)	Yes	See User Guide for details	Iterator that supports send(), throw(), and close().
Mapping (collections.abc)	Yes		Collection of key-value pairs.
MappingView (collections.abc)			View on dictionary's keys, values, or items.
MutableMapping (collections.abc)			Mapping that can be changed.
MutableSequence (collections.abc)	No	Use Sequence	Sequence that can be changed.
MutableSet (collections.abc)			Set that can be changed.
Reversible (collections.abc)			Supports reversed iteration.
Sequence (collections.abc)	Yes		Ordered collection of items.
Set (collections.abc)			Unordered collection of unique elements.
Sized (collections.abc)			Has a length.
ValuesView (collections.abc)			View on dictionary's values.
Awaitable (collections.abc)	No	Unlikely to be useful	Can be used in an await expression.
Coroutine (collections.abc)	Yes	See Async Support	Awaitable object with send(), throw(), and close().
AsyncIterable (collections.abc)	No	Issue	Object capable of async iteration.
AsyncIterator (collections.abc)	No	Issue	Async iterator object.

Class Reflection

Typed Dict

Construct (link)	Supported in CSnakes	Notes	Summary
TypedDict	No		Dictionary with a specific set of keys, each with a specific type.
NotRequired	No		Marks a key as not required in a TypedDict.
Required	No		Marks a key as required in a TypedDict.
ReadOnly	No		Marks a key as read-only in a TypedDict.

Protocols

Construct (link)	Supported in CSnakes	Notes	Summary
Protocol	No		Defines structural subtyping (static duck typing).