[PeCaN]

I've been working on something like this on and off for the past 4 years or so, although with something more like generators than streams.

I think it's a very, very promising idea (I admit to heavily being biased towards anything APL-influenced) although surprisingly difficult to get right. Gilad Bracha is obviously way smarter than me so I'm definitely curious where he goes with this.

One additional idea that I keep trying to make work is integrating variations of (constraint) logic programming and treating solutions to a predicate as a generator or stream that operations can be lifted to rank-polymorphically. As a simple example a range function could be defined and used like (imaginary illustrative syntax)

    range(n,m,x) :- n <= x, x <= m
    
    primesUpto(n) = range(2,n,r),               # create a generator containing all solutions wrt r
      mask(not(contains(outerProduct(*, r, r), r)), r)  # as in the video
    

I've never really gotten this to work nicely and it always feels like there's a sort of separation between the logic world and the array world. However this feels incredibly powerful, especially as part of some sort of database, so I keep returning to it even though I'm not really sure it goes anywhere super useful in the end.

[Groxx]

Have you seen Halide? https://halide-lang.org/

It's a bit special-cased (afaict), but it sounds like it makes at least a solid step in this sort of direction.

[hobby-coder-guy]

What does “:-“ mean?

[asimpletune]

Probably “such that”