lelf

@Adám what are the shortest “normal” APL quine? dfns.dyalog.com/n_quine.htm ?

@dzaima thanks. That (almost) explains it. I specifically checked ⎕drs, but the docs for ⎕dr don't say anything about it trying to auto-compact.

@ngn that -x is not necessary, just a (simple) way to do unfoldr (\x -> if cond x then Just (x, next x) else Nothing) a₀ would be nice [But that's just me, and I'm only "using" APL for 2 weeks, so maybe I'm completely wrong]

well... -{2/x}\42 in k7. but we're talking about apl

@ngn yes... but why would I ever want a recursion? ;)

@Adám like in Haskell, e. g. unfoldr (\x -> if x>0 then Just (-x, xdiv2) else Nothing) 42 is [-42,-21,-10,-5,-2,-1]. Here function returns (a) what elem goes to the result (-42), (b) the next state (xdiv2 aka {⌊⍵÷2}), (c) whether to stop (Just(v,state) or Nothing). Shouldn't be necessary that complex, but the idea is this.

@Adám tio.run/##SyzI0U2pTMzJT9dNzkksLs5M/v@ob2pm/…

@Adám BTW do you have an idea why is chat.stackexchange.com/transcript/message/52727538#52727538 ?

@Adám Thanks. Yes! I tried to search "iterate", "unfold"

@Adám I don't want "vector of 𝑛", I want «until g»

How would you do «f⍣g but giving intermediate results»?

@Sherlock9 I just did ,⍎¨⎕csv FILE 😇

I thought about that, but… ×1.5? :)

Interestingly, if I do ti←¯128+'UTF-8'⎕ucs t ⋄ si←¯128+⎕ucs s ⍝ -128 to fit to 8-byte ints and run si{+/2</(⍺=⍵),1}ti, it's ×1.5 slower. Any idea why? (ascii-only, so t and ti have the same size.)

ah

is @Bubbler's version slower because it is prepending ,?

@Adám I thought it's about 'abc'[/⍨1] (syntax error, is it a bug?) so I tried to add [(..)], that works for me on 17.0

⎕←cmpx 's{+/2</⍺=⍵,⍺}t' 's(+/2</⊣=⊢,⊣)t' ⊣ s←',' ⊣ ⎕←≢t←',XY'[(/⍨?1e6⍴3)] ⊣ 'cmpx'⎕CY'dfns'

@Adám how bad is an idea to do +/0 1⍷','≠',',str instead?

What is the shortest tacit form of {⍺⍵}? (⊂⊣),(⊂⊢) ?

"you probably want 0=≢⍵ instead of ⍵≡⍬" what is wrong with the latter?

Cool. “All numbers sans 2-number products”?

yes

⎕←X/⍨1<≢¨('^(..+?)\1+$'⎕r'∘')(,/⍕)¨¨1/¨⍨X←⍳100⊣'is my first apl program horrible enough?'

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

complained to support@

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

it accepts both actually. And both iotas it seems

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

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

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

apparently it exists as ⍥ in NARS2000

Is there a short way to write (f ⍺) g (f ⍵)?

Never mind, wrong ⎕io

I’m watching youtube.com/watch?v=EJONZpNA81s and 0 0⍉D←{{⍉⍵⍪1↓⊖⍵}⍣2⌽s⍴⍵,'-'⍴⍨s←2⍴≢⍵}'ABCD' (the 0 0⍉ part) gives an error. Has something changed in Dyalog APL?

Why you can do (⊃,⊃), but not (⍬⍴,⍬⍴)?

👍

@Adám 10000000000 ÷big 2. Was VALUE ERROR: Undefined name: E; now DOMAIN ERROR. But I'm a complete noob, so maybe I’m doing something wrong :)

Yes, I understand. Still surprising (and failing would be better than useless result)

@Adám I think big should rather fail in this case: 10000000000000000000 ×big 1 ;-)

@ngn what do you suggest? hosting only .diffs? also, thanks for the source!

@ktye yes. why?

is there an official list of prefix squiggles anywhere? ^ sorted, ? unique(?), ! iota

heh… 2\: 2 ⇒ 1 0, 2 \: 2 ⇒ class error

@ngn ...or are you supposed to think of it as a special case of func\term?

@ngn hah. Thanks. Is it documented anywhere?

what is list\atom in k7?

@ngn but echo $'"\n\t"' | ./shakti-2019.09.20/bin/k ⇒ "\n\t"

ah. Works in kdb's k4. But you can replace \n in k7 (?!): echo $'+/+1,(1=;<\':4=)@\:" \n\t\\r"? "foo bar quux"' | ./shakti-2019.09.20/bin/k

@ngn \r too then (as ^M)