I agree with you. The special handling of outermost strings vs. strings embedded inside annotations bugged me a lot. Now you convinced me that this functionality should be moved to `get_type_hints()` and the __future__ import shouldn't try to special-case this one instance, while leaving others as is.
I will be amending the PEP accordingly. - Ł > On Nov 19, 2017, at 10:56 AM, Mark Shannon <m...@hotpy.org> wrote: > > Hi, > > Overall I am strongly in favour of this PEP. It pretty much cures all the > ongoing pain of using PEP 3017 annotations for type hints. > > There is one thing I don't like however, and that is treating strings as if > the quotes weren't there. > While this seems like a superficial simplification to make transition easier, > it introduces inconsistency and will ultimately make both implementing and > using type hints harder. > > Having the treatment of strings depend on their depth in the AST seems > confusing and unnecessary: > "List[int]" becomes 'List[int]' # quotes removed > but > List["int"] becomes 'List["int"]' # quoted retained > > Also, > > T = "My unparseable annotation" > def f()->T: pass > > would remain legal, but > > def f()->"My unparseable annotation" > > would become illegal. > > The change in behaviour between the above two code snippets is already > confusing enough without making one of them a SyntaxError. > > Using annotations for purposes other than type hinting is legal and has been > for quite a while. > Also, PEP 484 type-hints are not the only type system in the Python > ecosystem. Cython has a long history of using static type hints. > > For tools other than MyPy, the inconsistent quoting is onerous and will > require double-quoting to prevent a parse error. > For example > > def foo()->"unsigned int": ... > > will become illegal and require the cumbersome > > def foo()->'"unsigned int"': ... > > Cheers, > Mark. > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/lukasz%40langa.pl
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