Maybe give sequences the ability to tell properties about their size, like the `SizeInfo` stuff Paul is talking about in the video. This would at least give meaningful hints to `count` to say whether it should try to count things at all, or just return some constant like `Infinity` or `undefined` or whatever. It's not a bad idea. Generally, I would think the size isn't as important as knowing whether or not I can conceivably `take` a number of things from the collection. I.e., if I am implementing a paged view of something, I only care to `take(n)` where `n` is some natural number. If `n` is more than the sequence contains, I'll just get `x` things where `x` is some number less than `n`, but above 0 (since an empty collection is `nil`.) Because we had a fixed upper bound, we know we can safely count the sequence, so the size info becomes superfluous and just extra stuff for the implementer of the sequence to care about.

So what I'm saying is that while size info is probably more interesting information than an actual size, I'm still not convinced it provides much value beyond satisfying curiosity.