[Python-3000] iostack and Oh Oh

[Bill Janssen]

> Actually, to me the thing that's a stretch from current practice is the 
> attempt to spell out in detail what a "mapping" is.

Good point :-).  Of course, that's the problem I'd like to see fixed
-- not knowing what a mapping is, or whether a particular value is
one.

> I'm not saying there is no such thing as "mapping", IOW, I am saying that 
> "mapping" is an informal shorthand for a collection of operations.  If you 
> want to be specific, refer to operations.  If you wish to be concise (but 
> vague) then refer to "mapping".

I think we're in agreement here.  It's just that using interfaces lets
us capture aspects of the semantics of that grouping of operations
which may not be expressible in the description of the operations
themselves.  And using types to define interfaces allows us to re-use
code in a way that's just not possible in other interface-based
languages, like Java.

Bill