@Adám How does this look

@Marshall fwiw your webassembly compiler relies on the fact that ¯52↑2|f⍟⟨⟩num works (Enc2 with 0 as 𝕨); noticed as i'm working on maybe improving my pervasion stuff and kept the null prototype through 2|

@dzaima (to be more precise of why it failed, I hadn't specified that an EmptyArr can be used as bit/int/double/char arrays, so fixing on my side only had upsides. Just noting as an aside about prototypes being messy)

@dzaima I hadn't thought of that case so thanks for pointing it out. I think the policy to use is for f⍟⟨⟩x to have (fill-ified) x as the fill element. More generally every empty array with atomic fill (including those in prototypes?) would have x substituted for its fill.

@dzaima (that "maybe" is looking like a "no" currently. No benefits and up to 2.4% slowdown)

@Razetime codegolf.codidact.com/questions/279159 is just {⍵⊥⌽⍺} (or ⊥∘⌽⍨)

@rak1507 (or of course just ⊥∘⌽)

Then you'd have to take the arguments the other way round

@rak1507 which is not forbidden

Fair enough