[xelxebar]

You absolutely rock. Thanks for taking a look at my project. It's currently on the back-burner right now, but I do have future plans. The ¯2 is specifically something I'm hoping to get rid of. It has to do with some specifics of handling leading sigils, but it's slightly broken and the ugliness of ¯2 signals to me that it needs to be fixed.

Hoping to hear your thoughts in the future once the project is more in shape!

[mlochbaum]

In the BQN compiler I'd write (⊂¯1++⍀m)⌷(m←c=LF)⌿ as the equivalent of (⊂⌈⍀m×⍳≢m←c=LF)⌷ using the function IT (indices-times but it also includes the ⌈⍀). Although I'm not sure it's inherently faster. Most of the cost is in selection, and there's an algorithm taking a shuffle of a sliding window from the right argument that would work better with the denser indices. And those indices have a smaller type which may be useful. The annoying thing is that this whole set-and-hold operation could be implemented in SIMD directly and none of those complications would apply. But it's pretty hard to expose in a nice way without just providing a builtin.