Ideas for extensions of dol -- namely when we will re-architecture it

[thorwhalen]

Include hooks

Example: filt_iter

What I really wish for is a way to control the way that filter(filt, iterable) will work via the iterable.
That way, when there's a different, perhaps more optimized way, to apply filt to the iterable, we can use that.
For example, say you want express your filt to be a mongo query that will be sent to the remote DB to filter the items closer to the data. That's much less wasteful than asking for the items to be sent one by one over the wire, only to filter out most of them!

But there's apparently no way to control builtin filter from an iterable (that same way, for example, that you can control what iter or len does, via the __iter__ and __len__ methods of the iterable.

That said, we can control what we wrote: Namely filt_iter. We can tell it to first see if the wrapped mapping has a _filter_ method, and if so, pass the job on to it.