PEP 245

[Clark C. Evans]

> This is my own experiment with adapters and interfaces. I could not join 
> the SourceForge project, and I dont know how things are being implemented 
> right now. Use as you wish (even as a example of don't-do-this <wink>).

The current source code is at http://adapt.sourceforge.net/adapt.py
you shouldn't need a IE browser to access this.  Also, the PEP is
at http://python.sourceforge.net/peps/pep-0246.html

>  >>> for i in f.__adapt__(I1_Sequence): print i
> ...
> 1
> 2
> 3
> 4

Ok.  According to the PEP, you could write this as:

  import adapt from adapt
  for i in adapt(f,I1_Sequence): print i

And then, in your FakeSequence, you should use __conform__
instead of __adapt__  (__adapt__ is used in the protocol)

>    def __adapt__(self, protocol):
>      if protocol == I1_Sequence:
>        return MakeInterfaceAdapter_V1(protocol, self, self.ir_sequence)
>      elif protocol == I2_Sequence:
>        return MakeInterfaceAdapter_V2(protocol, self, self.ir_sequence)
>      else:
>        return None

Let's say you are now introducing an I3_Sequence, and 
FakeSequence is already fixed and distributed to too many
clients to be resonably changeable.  You can give the
I3_Sequence class an __adapt__ method which knows
about FakeSequence and returns the appropriate adapter.
This is the bi-directional part...

;) Clark