The APL Orchard

12:30 AM

@Adám hi, but i only have a cmc, CMC: remove the duplicates of character like "31415" => "3145"

∪

⋄∪'31415926535897932384626338327950'

@Adám TryAPL bot down?

@Fmbalbuena bot error (not TryAPL or your code's issue) running this code; if this persists, please contact a developer

what happened to @TryAPL?

@TryAPL are you ok? what happened?

⎕←'OK'

12:33 AM

@Adám OK

I rebooted the server.

What happened?

⋄∪'31415926535897932384626338327950'

@Fmbalbuena 3145926870

@Adám Does APL support yield?

What is "Yield"?

12:34 AM

example (pseudocode)

def X without args
 loop
  yield 1
for I in call X
 output I

@Adám ^ prints 1 infinitely

like return but list

11Kilobytes

so streams/lazy evaluation. no methinks.

or better, call X returns [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1...]

Not Dyalog APL. KAP maybe.

KAP?

apl.wiki/KAP

12:39 AM

or @Adám APL supports infinite list?

Not Dyalog APL. KAP maybe.

or @Adám APL supports infinite string?

APL doesn't support any strings at all, infinite or not.

wait, WHAT?

'abc' is valid string in APL

It is valid APL, but not a string. It is a list of characters.

APLers tend to call it a character vector.

12:42 AM

⋄'a' 'b' 'c'≡'abc'

@Fmbalbuena 1

@TryAPL why?

Because APL has no strings, only character lists!

⋄'a' 'b' 'c'

@Fmbalbuena abc

12:43 AM

the output seems the same but what if

⋄'a' 'b' 'c' 2 'a' 'b' 1 'a' 0

@Fmbalbuena abc 2 ab 1 a 0

This is a list of a mixture of characters and numbers.

What you've discovered is that APL arrays need not be homogeneous.

@Adám CMC: quine without ⌽

I'm not good at quines.

@Adám Is APL TC with only 32-128 and "←⍵⎕" only?

12:50 AM

I don't know.

Actually, I think it might just be.

You'd have logical AND ^ and NOT ~ which means you can construct any logic gate.

You can write a tail-recursive function using the function name.

You have comparisons < = > which can be combined with ~.

You can scan and reduce, replicate and expand, concatenate, index, and change values at specific indices or by condition with @

Flow control can be done with :

It should be possible to implement Rule 110.

1:29 AM

@Fmbalbuena Yes:

 result←steps Rule110 now;i;step;next;pad
 result←0/[1]⎕FMT steps 1 steps/' '
 :For step :In +\steps/1
     pad←(steps-step-1)/0
     result,[1]←pad,now,pad
     next←0/0
     now←0,now,0
     :For i :In +\now=now
         :Select (0,now,0)[i+0 1 2]
         :CaseList (1 1 1)(1 0 0)(0 0 0)
             next,←0
         :Else
             next,←1
         :EndSelect
     :EndFor
     now←next
 :EndFor
 result,[1]←now

2 hours later…

Razetime

2:59 AM

Does anyone know which method of Fast Fourier Transform is used in aplcart?

2 hours later…

Razetime

4:41 AM

Anyone got APL solutions to day 23

6 hours later…

10:11 AM

@Razetime It is from code.jsoftware.com/wiki/Essays/FFT by way of dfns.dyalog.com/n_xtimes.htm

Razetime

10:39 AM

thanks!i

@Adám what exactly does Indices of all items of array of shape Jv mean?

entry is ⍳Jv

@PyGamer0 Let's say you have a matrix of 2 rows and 3 columns. All the valid indices into that array are ⎕←⍳2 3

@Adám
┌───┬───┬───┐
│1 1│1 2│1 3│
├───┼───┼───┤
│2 1│2 2│2 3│
└───┴───┴───┘

⎕←(2 3⍴⍳6)[⍳2 3]

@PyGamer0
1 2 3
4 5 6

10:41 AM

ah i see

@Adám example usage of this functionality?

A: Dijkstra's Challenge

APL, 13 12 bytes 1 byte thanks to @jimmy23013. 1-indexed. The array is stored in the variable m. +/,m×m=+/¨⍳⍴m +/∊m∩¨+/¨⍳⍴m Try it online! Based on the answer in J, which is a language based on APL. In TryAPL, to key in: +/m`em`c`1+/`1`i`rm With the array: +/m`em`c`1+/`1`i`rm `[ 2 4 `r 3 `

11:06 AM

@Oberon Hi there, and welcome to the APL Orchard!

Oberon

Hello!

You have quite some experience with APL, I can tell.

11:33 AM

@Adám is the dyalog logo based on ⊃∨∧⌊○⊂?

That's my assumption, but I don't actually know. I can ask the CEO…

⋄⊃∨∧⌊○⊂

@PyGamer0
┌─┴─┐
⊃ ┌─┼───┐
  ∨ ∧ ┌─┼─┐
      ⌊ ○ ⊂

⋄ 2(⊃∨∧⌊○⊂)2

@PyGamer0 Response looks like a 1-by-0 matrix.

11:40 AM

Maybe I'll use ⍬(⊃∨∧⌊○⊂)⍬ next time I need ⍬

1 hour later…

1:08 PM

min←((⊢~⌈/)⊢)⍣(2=∘≢⊢) can this "joke" minimum function be golfed in some way?

@KamilaSzewczyk ((⊢~⌈/)⊢) is just (⊢~⌈/)

it's not. valence matters :)

or does it?

when i tested it, it gave weird results as a dyadic fork.

i presume ⍺⍺ ⍣ ⍵⍵ calls ⍺⍺ monadically and ⍵⍵ dyadically

I get something strange when I try to change the left piece. Why (2=≢) [or (2∘=≢)] doesn't work?

because the right operand is called dyadically

not monadically

@KamilaSzewczyk Dyadically between what?

1:22 PM

previous and current application result, i presume.

help.dyalog.com/15.0/Content/Language/Primitive%20Operators/…

@KamilaSzewczyk Oh yes, for example when you do ⍣≡

2 hours later…

11Kilobytes

3:29 PM

How do you get newlines for debugging?

11Kilobytes

4:05 PM

⎕UCS 10 is the unicode newline character.

4:17 PM

@Adám Try it online!

6 hours later…