@B.Wilson @Silas Should ⍸⍣¯1 (or maybe better {⍵∊⍨⍳⊃⌈/⍵}) be a primitive? Monadic ⍷ might make sense. A shape left argument, i.e. {⍺←⊃⌈/⍵ ⋄ ⍵∊⍨⍳⍺} might be nice, but ↑∘⍷ isn't exactly rocket science.
@Adám I'd almost want a primitive ⍣¯1 operator instead, a la Kap, BQN, and Uiua. Though, perhaps it's more just that I don't reach for ⍸⍣¯1 enough. Need to stew on this a bit.
@B.Wilson ⍣ isn't very often needed. These are the only instances on APLcart:
⊥⍣¯1
+\⍣¯1
≠\⍣¯1
×∘*⍨⍣¯1
⍸⍣¯1
And ⊥⍣¯1 is only needed because scalar⊤ is badly designed.
I might be more interested in ⍣¯1 if we supported more inverses, including some interesting (=arbitrary) ones like ×/⍣¯1 giving prime factors (padded with 1s), ⍴⍣¯1 gave ⊢⍴∘⍳×/ etc.
