[Python-Dev] pprint(iterator)

[Paul Moore]

2009/2/2 Nick Coghlan <ncoghlan at gmail.com>:
> A trio of patches that:
> 1. promoted simplegeneric from pkgutil to functools (with appropriate
> documentation and tests)
> 2. changed pkgutil to use functools.simplegeneric instead of its current
>  internal version
> 3. updated pprint to be a generic function (and hence more easily
> extensible via the ABC mechanism, while still keeping it's current
> special cases as necessary)
>
> would certainly be an interesting thing to see (with patch 3 being the
> poster child for why patch 1 is a good idea).

I'll see what I can do. I can't promise much for (3) as I don't
personally have a need for it, so my understanding of the use cases is
limited at best. But (1) and (2) should be possible.

Can I assign the patches to you (for review, at least)?

> The major virtue of such a basic generic framework is that it is much
> easier to explain than the all-singing all-dancing overloading system
> described in PEP 3124. Type-based dispatch on the first argument is
> fairly straightforward to describe in terms that make sense to anyone
> that is already familiar with dynamic dispatch of class and instance
> methods. It's only when you get into more exotic dispatch conditions and
> up-calls and the like that people's eyes start to glaze over.

Agreed. And given that the simple case probably covers 90% of the
practical requirements, that's a shame.

Paul.