[Python-3000] More PEP 3101 changes incoming

[Greg Ewing]

Ron Adam wrote:
>     - alter the value and return (new_value, format_spec)
>     - alter the format_spec and return (value, new_format_spec)
>     - do logging of some values, and return the (value, format_spec) 
> unchanged.

I would ditch all of these. They're not necessary, as
the same effect can be achieved by explicitly calling
another __format__ method, or one's own __format__
method with different args, and returning the result.

>     - do something entirely different and return ('', None)

I don't understand. What is meant to happen in that case?

> Does this look ok, or would you do it a different way?

You haven't explained how this addresses the 'r' issue
without requiring every __format__ method to recognise
and deal with it.

--
Greg