[Python-Dev] PEP 246, redux

[Raymond Hettinger]

> Thus, my argument is that an adapter like this should never be made
part
> of
> the adapter system, even if there's no transitivity.  However, if you
> agree
> that such an adapter shouldn't be implicit, then it logically follows
that
> there is no problem with allowing transitivity, except of course that
> people may sometimes break the rule.

At some point, the PEP should be extended to include a list of best
practices and anti-patterns for using adapters.  I don't find issues of
transitivity and implicit conversion to be immediately obvious.

Also, it is not clear to me how or if existing manual adaption practices
should change.  For example, if I need a file-like interface to a
string, I currently wrap it with StringIO.  How will that change it the
future?  By an explicit adapt/conform pair?  Or by strings knowing how
to conform to file-like requests?


Raymond Hettinger