Hey @Adám, is there a way to apply a function pairwise without overlapping? As in 2+/⍳4 = 3 7 instead of 3 5 7?

⍞←{+/⍵}⌺(⍪2 2)⍳4

@Adám 3 7

@J.Sallé ^^ Stencil is for more than just GoL.

Ah, Stencil! Nice, I'll try to do that

@Adám another one: can I use @ with a binary vector somehow? I want to append a character at the truthy indexes of the given vector, something like 0,@(0 1 0 1)⍳4 → 1 02 3 04

⎕←0,¨@{0 1 0 1}⍳4

@Adám
┌─┬───┬─┬───┐
│1│0 2│3│0 4│
└─┴───┴─┴───┘

@J.Sallé ^^

ah, I gotta use braces instead of parens, I see

@J.Sallé Not exactly; f ⍵⍵ is a function, it must return a binary mask, if ⍵⍵ is an array, it must be indices.

Yeah, this is gonna get very convoluted >.>

I'm having trouble just padding odd length integers with a 0

@J.Sallé What is an odd length integer?

@Adám odd number of digits is what I mean

@J.Sallé Remember that the number of digits is 1+⌊10⍟?

Also the input is not very flexible so I have to take a list of integers instead of a list of list of digits or a list of strings

@Adám I most certainly did not remember that. I don't think I've used ⍟ at all since the lesson about it >.>

@Adám ≢⍕ is golfier

I think the trouble I'm having is with adding the 0 to the specific integers in the input

@dzaima You mean ≢∘⍕¨.

I've got {0,¨@{2|≢∘⍕¨⍵}⍵⊢⍵}(19)(91)(234)(2023) at the moment

And that still doesn't do what I need exactly

@J.Sallé ⍵⊢⍵‽

@Adám that was a derp

I thought I had to use one ⍵ for the inner dfn and one for @ operator

@J.Sallé {⍵↑⍨-2×⌈.5×≢⍵}¨⍎¨¨⍕¨ 19 91 234 2023 is what I've got, but that outputs a list of digits

@dzaima yeah, I had a similar one that also did that

You want to add a leading 0 if odd-digited?

@Adám yeah, that was what I needed. I just noticed dzaima already answered the challenge in APL though, so I think I'm gonna try doing it in K or J

About time I learned some of that