@Bubbler Can you TIO it failing?

@Adám Try it online!

@Bubbler Try it online!

if ⍺(f g h)⍵ is (⍺f⍵)g(⍺h⍵) then why ⍺(f∘h)⍵ is ⍺f(h ⍵) (isn’t it?)

@lelf The ∘ (called Jot) is an operator, not a function. It binds tighter than a train, and it forms a single function from its left and right operands. So (f∘h) works differently from f g h. "⍺(f∘h)⍵ is ⍺f(h ⍵)" is just the definition of Jot.

SEDE query for indefinite APL bounty hunters :)

@Adám How exactly does ⊤ (encode) work with non-integral left argument?

@lelf (f+g)(x) in Traditional Mathematical Notation (TMN) is (f+g)(x) in APL. (f∘g)(x) in TMN is (f∘g)(x) in APL. Now we add a left argument (using dot notation): (f+g)(x) ⇔ f(x)+g(x) → x.(f+g)(y) ⇔ x.f(y)+x.g(y) which in APL is (x f y)+(x g y). Similarly, (f∘g)(x) ⇔ f(g(x)) → x.(f∘g)(y) ⇔ x.f(g(y)) which in APL is x f g y.

@Bubbler Does this model help?

 Rp←{
     ⎕CT←0
     pv←1↓⌽×\⌽⍺,1 ⍝ position values
     already←0,⍨¯1↓pv|⍵ ⍝ represented further right
     ⍺|pv÷⍨⍵-already
 }

a simpler model outputting the result in reverse would be {{⎕←⍺|⍵ ⋄ ⌊⍵÷⍺}/⍺,⍵} (which would be more prettily describable as a loop with an accumulator but apl doesn't really make that easy)

@dzaima Doesn't that divide by zero?

@dzaima {⎕DIV←0 ⋄ r⊣{r,←⍺|⍵ ⋄ ⌊⍵÷⍺}/⍺,⍵⊣r←⍬} seems to work.

@Adám with a zero in ⍺ you mean? yeah, but imo that's just an afterthought (or a prethought of replacing 0 with ∞)

And that's a nice hint for golfing the zeckendorf thing

@Traws Hey there. Interested in APL?

Not sure I understand the error for this: 'bsearch'⎕CY'dfns' ⋄ {w←⍵ ◊({w≤⍵}bsearch 0 1)}1

@Adám Hey! Just looking around.

@Traws Not a problem. Let me know if you want an intro to APL.

@lelf w←⍵ ◊({w≤⍵} has a fake diamond:

⋄ 'bsearch'⎕CY'dfns' ⋄ ⎕←{w←⍵ ⋄({w≤⍵}bsearch 0 1)}1

@DyalogAPL Hello?

⍞←{w←⍵ ⋄({w≤⍵}bsearch 0 1)}1 ⊣ 'bsearch'⎕CY'dfns'

@Adám 1

Thank you.

(Oh, I get it. It is really a dfn body, so a non-assignment terminates.)

@Adám a-ha! Thanks. Blame emacs’ APL input-mode :)

@lelf The emacs mode is made for GNU APL which uses a different Unicode diamond!

it accepts both actually. And both iotas it seems

@lelf [Relevant](sudleyplace.com/APL/APL%20Characters%20and %20Their%20Aliases.pdf). I suggest you complain to support@dyalog.com that we should handle all aliases.

Fixed link

now trying it, gnu apl accepts pretty much everything… both alphas, omegas, even minuses (ascii hyphen & mathematical minus U+2212). Edit: ah, it's all in the pdf you posted

@lelf Almost. GNU added "dfns" after that doc was written, so it doesn't mention ⍺⍵ in GNU.

complained to support@

⎕←1∣2|3 ⍝ interestingly, some doppelgängers are already accepted

@lelf You can't use comments with the bot.

⎕←1∣2|3 ⊣ 'interestingly, some doppelgängers are already accepted'

@Adám
0

@lelf And yes, two to be precise, that one and ∧ vs ^.

I personally think that if Dyalog wants to position itself as the ultimate APL for the future, it should eat all the synonyms (but normalise immediately).