[Python-Dev] PEP 246, redux

[Clark C. Evans]

On Mon, Jan 10, 2005 at 01:34:59PM -0500, Phillip J. Eby wrote:
| The performance penalty I was talking about was for using an abstract 
| base class, in a subclass with a __conform__ method for conformance to 
| other protocols.  In this case, __conform__ will be uselessly called 
| every time the object is adapted to the abstract base class.

*nod*

If this proposal was "packaged" with an "interface" mechanism, would
this address your concern?  In this scenerio, there are two cases:

  - Older classes will most likely not have a __conform__ method.
  - Newer classes will use the 'interface' mechanism.

In this scenerio, there isn't a performance penalty for the 
usual case; and for migration purposes, a flag could be added
to disable the checking.

Best,

Clark