pre-PEP: The create statement

[Steven Bethard]

Carl Banks wrote:
> Steven Bethard wrote:
>> This PEP proposes a generalization of the class-declaration syntax,
>> the ``create`` statement. The proposed syntax and semantics parallel
>> the syntax for class definition, and so::
>>
>>     create <callable> <name> <tuple>:
>>         <block>
>>
>> is translated into the assignment::
>>
>>     <name> = <callable>("<name>", <tuple>, <namespace>)
>>
>> where ``<namespace>`` is the dict created by executing ``<block>``.
>> The PEP is based on a suggestion [1]_ from Michele Simionato on the
>> python-dev list.
> 
> And who needs a class statement after that?
> 
> create type A:
>     <block>
> 
> That's probably even more readable than class A, if not as familiar.
> My biggest concern with this is the special arguments of the caller.
> It breaks my heart that we couldn't do something like this:
> 
> create dict keymap:
>     A = 1
>     B = 2
> 
> And it'll probably confuse people as well.  We ought to keep that in
> mind.

This is definitely an important point.  I've thought about this a bit 
and I'm still not sure which way is the right way to go on this.  If the 
tuple and dict arguments actually get passed as *args and **kwargs 
arguments, the create statement could be used with a much wider variety 
of existing callables.  I've updated the open issues section of the PEP 
to point this out.

STeVe