[Cython] [cython] Hide Cython utility classes (like memoryview) from Python level module scope. (#222)

[Nikita Nemkin]

On Sun, 05 May 2013 17:03:54 +0600, Stefan Behnel <stefan_ml at behnel.de>  
wrote:

> Nikita Nemkin, 04.05.2013 19:52:
>> Two changes included:
>>
>> 1) cdef classes in utility code can have compiler directives attached  
>> to them. This is not used anywhere ATM, but memoryviews may benefit  
>> from ``@cython.final``.
>>
>> 2) All utility classes are excluded from module dictionary by  
>> *implicitly* marking them with ``@cython.internal`` . This fixes  
>> [#775](http://trac.cython.org/cython_trac/ticket/775), test is included.
>>
>> I don't quite understand what CythonScope is and how utility  
>> classes are *supposed* to be hidden, but as it is now, utility code  
>> scope is merged into main module scope and there is nothing special  
>> about its classes.
>>
>> BTW if a user declares his own class with the same name as utility  
>> class (for example, ``memoryview``), everything breaks down.
>
> I wonder why utility classes actually need a Python name. Can't they just
> live with None as "name"? All they should really need is their cname and  
> a
> properly analysed entry stored in the right places, so deleting their
> Python visible name when merging them into the main module should fix  
> this.

entry.name serves for general identification and bookkeeping, not just
to provide a python level name. Non-null entry name is a very useful
invariant, I'd rather not break it for something trivial like name hiding.

All codegen algorithms will have to worry about (class) entries with null
names afterwards. Even if it works currently, it may break in the future.

Anyway, just setting entry.name to None does not work, because it is not
the only place to get a python name (and of course it's never checked for  
None).
For example, module init code uses ClassScope.class_name. Some other code
may use entry.type.name etc...


Best regards,
Nikita Nemkin