On Fri, May 22, 2015 at 10:23 AM, Jim J. Jewett <jimjjew...@gmail.com> wrote:
> > > At Thu May 21 22:27:50 CEST 2015, Guido wrote: > > > I want to encourage users to think about annotations as types, > > and for most users the distinction between type and class is > > too subtle, > > So what is the distinction that you are trying to make? > > That a type refers to a variable (name), and a class refers to a > piece of data (object) that might be bound to that name? > Sort of. But really a type is something in the mind of the type checker (or the programmer) while the class is a concept that can be inspected at runtime. > Whatever the intended distinction is, please be explicit in the > PEP, even if you decide to paper it over in normal code. For > example, the above distinction would help to explain why the > typing types can't be directly instantiated, since they aren't > meant to refer to specific data. (They can still be used as > superclasses because practicality beats purity, and using them > as a marker base class is practical.) > There will have to be documentation and tutorials beyond the PEP. The PEP mostly defines a standard to be used by people implementing type checkers. -- --Guido van Rossum (python.org/~guido)
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