ktye/iv - there goes another one

@ngn and it's made in Golang, very nice.

@ngn Supposed to feature channels, whatever that is.

FYI re: my comments earlier on Excel reddit.com/r/excel/comments/ajp0mx/array_programming_revival

@ngn wow, good find

@Adám channels are a kind of data structure in Go. They work kinda like infinite lists, but are mainly used for concurrency. So channel <- value adds value to channel, and likewise value <- channel assigns the first element of channel to value.

The interesting bit about channels is this: "By default, sends and receives block until the other side is ready. This allows goroutines to synchronize without explicit locks or condition variables."

So if you have two routines adding something to a channel, the result of the first routine will be added to the channel first regardless of which one finishes first.

@J.Sallé Sounds like our futures.

@ngn interesting

is "APL\iv" something specific? i haven't heard that term before

@feeb i don't know. it might have something to do with ivy (Rob Pike's take on apl from a couple of years ago) or it could be completely unrelated

if i have a vector of matrices, how can i index with those in another matrix, taking each item in the vector as the coordinates in the nth dimension?

the obvious way is to interleave the matrices to a matrix of vectors, but that's pretty inefficient

@dzaima example?

i suspect some combination of ⊃ and ⍤ might work

@ngn tio.run/##SyzI0U2pTMzJT/8PBImP2iYYKxg/…

it in the actual code; yes, that cellular automaton again, wanted to give apl a go

@dzaima ((2 2⍴1 3 2 3),[2.5](2 2⍴3 2 1 3))⌷⍤1 2⊢a

@ngn oh cool, thanks. still have no idea how to use ⍤ :|

@dzaima f⍤m n applies f to m-cells on the left and n-cells on the right

a "k-cell" is a subarray of rank k. its shape is a suffix of the shape of the larger array

@ngn right. technically i know how it works, but finding/seeing uses for it is what's hard

not that much of a speedup, hmm.

@dzaima i didn't measure, to be honest