Thanks for your consideration. I'm currently fixing what's been asked in the reviews.

> But it would be useful to provide also word and sentence iterators.

I'll gladly do that as well!

> I think emitting a pair (pos, substring) would be more useful.

That means emitting a pair like ((start, end), substr) ? Is it pythonic to return a structure like this?

For what it's worth, I don't like it, but I definitely understand the value of it. I'd prefer having two versions. One returning indexes, the other returning substrings.

But...

> Alternatively an iterator could emit slice objects.

I really like that. Do we have a clear common agreement or preference on any option?