[Python-Dev] PEP 246: lossless and stateless

[Phillip J. Eby]

At 01:20 PM 1/15/05 +0000, Paul Moore wrote:
>I think there are the following distinct threads of discussion going
>on at the moment:
>
>* Details of what should be in PEP 246
>* Discussions spinning off from Guido's type-declaration-as-adaptation 
>proposal

My understanding was that the first needed to be considered in context of 
the second, since it was the second which gave an implicit blessing to the 
first.  PEP 246 had languished in relative obscurity for a long time until 
Guido's blessing it for type declarations brought it back into the 
spotlight.  So, I thought it important to frame its discussion in terms of 
its use for type declaration.


>* Discussion of what counts as a "good" adapter

Alex was originally trying to add to PEP 246 some recommendations regarding 
"good" vs. "bad" adaptation, so this is actually part of "what should be in 
PEP 246"


>* Philip's new generic function / ducy typing proposals

And of course this one is an attempt to unify everything and replace PEP 
245 (not 246) with a hopefully more pythonic way of defining interfaces and 
adapters.  I hope to define a "relatively safe" subset of PEP 246 for type 
declarations that can be done automatically by Python, in a way that's also 
conceptually compatible with COM and Java casting (possibly making Jython 
and IronPython's lives a little easier re: type declarations).