Namespaces are one honking great idea

[Steven D'Aprano]

On Tuesday 05 July 2016 13:47, Chris Angelico wrote:

> On Tue, Jul 5, 2016 at 1:35 PM, Steven D'Aprano <steve at pearwood.info> wrote:
>>> If you push your code into a separate .py file, you can reference the
>>> original module by importing it. Is that also the normal way to use
>>> "outer" functions etc from inside a namespace?
>>
>> Good question!
>>
>> With the current implementation, importing should work, but it's not
>> necessary. The surrounding module (the real .py module) is inserted into
>> the name resolution path of functions:
>>
>> py> x = 999
>> py> @namespace.Namespace
>> ... class Test:
>> ...     def test():
>> ...             print(x)
>> ...
>> py> Test.test()
>> 999
> 
> Ah, fascinating. This does break the "just unindent and move to a new
> file if you want to break it out" equivalency, but it does make sense
> - it's a *nested* namespace, which modules (even in a package) are
> not. So you have the outer namespace acting pretty much the way
> builtins do. (Do nested namespaces work?)

I haven't got that far, but I expect that nested namespaces will be nested in 
name only, like nested functions in Python 1.5.

There's only so far I can go without support from the compiler. If you nest a 
class inside another class, the inner class doesn't see variables in the outer 
class even during construction. So I'm pretty sure my namespace metaclass will 
inherit the same limitation.



-- 
Steve