[Python-Dev] PEP 362 Third Revision

[Yury Selivanov]

On 2012-06-14, at 12:32 PM, Benjamin Peterson wrote:

> 2012/6/14 Yury Selivanov <yselivanov.ml at gmail.com>:
>> On 2012-06-14, at 11:24 AM, Brett Cannon wrote:
>>> On Thu, Jun 14, 2012 at 9:50 AM, Yury Selivanov <yselivanov.ml at gmail.com> wrote:
>>> 
>>> [SNIP]
>>> 
>>> Let's consider replacement of 'Parameter.is_*' set of attributes with
>>> a single 'Parameter.kind' attribute, which will have the following
>>> possible values: 'positional', 'vararg', 'keyword-only', 'varkwarg'.
>>> 
>>> (I think 'positional' is more intuitive than 'index'?)
>>> 
>>> 
>>> +1 if this change is made.
>> 
>> How about adding 'kind' and keeping 'is_*' attributes,
>> but making them read-only dynamic properties, i.e.:
>> 
>>   class Parameter:
>>       ...
>> 
>>       @property
>>       def is_vararg(self):
>>           return self.kind == 'vararg'
>> 
>>       ...
>> 
>> ?
> 
> Seems a bit bloatly to me. (One way to do it.)

Yes, but on the other hand it solves "strings are error prone"
argument, keeps all 'is_*' attributes in sync, and makes them
read-only.

'kind' property may do validation on set, to diminish mistakes
probability even further.

-
Yury