... and, runtime type checking (like https://github.com/agronholm/typeguard) must have a synthetised Union[] in __annotations__.
Le jeu. 29 août 2019 à 15:02, Philippe Prados <philippe.pra...@gmail.com> a écrit : > No, it's not possible, because > > >>> int | str > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > TypeError: unsupported operand type(s) for |: 'type' and 'type' > > Regards > > Philippe Prados > > > Le jeu. 29 août 2019 à 14:55, Inada Naoki <songofaca...@gmail.com> a > écrit : > >> I don't want to add runtime behaviors for static type hinting. >> >> There is PEP 563 instead. >> Tools like mypy can implement them without touching runtime behavior. >> >> >> On Thu, Aug 29, 2019 at 9:48 PM Philippe Prados < >> philippe.pra...@gmail.com> wrote: >> >>> Hello everybody, >>> >>> Scala 3 propose the a new syntax for Union type. See here >>> <https://dotty.epfl.ch/docs/reference/new-types/union-types.html>. I >>> propose to add a similar syntax in Python. >>> >>> # Operator for Union >>> assert( int | str == Union[int,str]) >>> assert( int | str | float == Union[int,str,float]) >>> # Operator for Optional >>> assert( ~int == Optional[int]) >>> >>> Now, it's possible to write: >>> >>> def fn(bag:List[int | str], option: ~int = None) -> float | str: ... >>> >>> in place of >>> >>> def fn(bag:List[Option[int,str]], option: Optional[int] = None) -> >>> Union[float,str]: ... >>> >>> I think these syntaxes are more clear, and can help with the adoption of >>> typing. >>> >>> >>> I test and implement these ideas in a two fork : One for CPython >>> <https://github.com/pprados/cpython> and one for MyPy >>> <https://github.com/pprados/mypy>. See the branches add_OR_to_types >>> (for Union syntax) or add_INVERT_to_types (for Union and Optional >>> syntax). >>> >>> How I implement that ? I add the operators __or__ and __revert__ to >>> PyType_Type. The C code is similar of : >>> >>> from typing import * >>> def type_or(self,right): >>> return Union[self,right] >>> type(type).__or__ = type_or >>> >>> Actually, the accepted syntax for typing is : >>> >>> annotation: name_type >>> name_type: NAME (args)? >>> args: '[' paramslist ']' >>> paramslist: annotation (',' annotation)* [','] >>> >>> I propose to extend the syntax to : >>> >>> annotation: ( name_type | or_type | invert_type ) >>> name_type: NAME (args)? >>> args: '[' paramslist ']' >>> paramslist: annotation (',' annotation)* [','] >>> >>> or_type: name_type '|' annotation >>> >>> invert_type: '~' annotation >>> >>> >>> What do you think about that ? >>> >>> The draft of a PEP is here >>> <https://github.com/pprados/peps/blob/master/pep-9999.rst>. >>> >>> Regards >>> _______________________________________________ >>> Python-ideas mailing list -- python-ideas@python.org >>> To unsubscribe send an email to python-ideas-le...@python.org >>> https://mail.python.org/mailman3/lists/python-ideas.python.org/ >>> Message archived at >>> https://mail.python.org/archives/list/python-ideas@python.org/message/FCTXGDT2NNKRJQ6CDEPWUXHVG2AAQZZY/ >>> Code of Conduct: http://python.org/psf/codeofconduct/ >>> >> >> >> -- >> Inada Naoki <songofaca...@gmail.com> >> >
_______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/RB6MGEMFLGEOJU7UEMR7A2XR2JOTT6YG/ Code of Conduct: http://python.org/psf/codeofconduct/
