The APL Orchard

@Fmbalbuena if you do not put in the effort to solve your own problem before asking a question here, then you guarantee that other people will not put in the effort to answer that question.

Fmbalbuena

I can't

Adám

What goes wrong in the process?

Fmbalbuena

How to add a folder?

Adám

@Fmbalbuena It says in the guide under "Create a folder".

xpqz

@Adám I see cultivation lesson 2 covers defining your own operators... hard core.

Razetime

3:33 PM

is Nial discussion on topic here?

Adám

@xpqz I think I mentioned to you that the order of the lessons is less than ideal.

@Razetime I think so (closer to APL than J — which is on topic — no?), but there's probably not much of an audience.

xpqz

It works, though, I think. Easy to dip in and out.

Razetime

yeah, figures.

i guess i'll put some of my nial exploits here whenever i get a chance

Fawn Locke

I'm glad you're enjoying Nial, Raze. It's a pleasant language :)

Fmbalbuena

I made APL folder in APL folder in a folder. How to flatten?

Razetime

3:35 PM

@FawnLocke oh, you use it as well?

oh wait you're awagga

nvm

Adám

@Fmbalbuena You can move the bookmark by following the guide under "Move a bookmark to a different folder".

Razetime

@Fmbalbuena if you have older siblings/parents you may want to ask them instead

Adám

It doesn't say how to delete the superfluous folder, but I assume it is similar to how one deletes bookmarks. See "Delete a bookmark".

Fmbalbuena

Ok

Adám

So you successfully got it bookmarked?

Fmbalbuena

3:38 PM

@Adám thanks

But I'm adding

Fawn Locke

Sorry to distract, is there a nice way to do ((⍺ ⍵⍵ 1⌷⍵) ⍵⍵ 2⌷⍵) for the length of ⍵ I suspected eachright could be useful and searched the aplcart for it

Alex B

@Adám you are probably the most patient person on the planet... LOL

Richard

:) sitting on my hands :)

Adám

@FawnLocke Each-right is X∘f¨Y or (⊂X)f¨Y

Isn't this a reduction?

Fawn Locke

Thanks, I'll see if that helps :)

Fmbalbuena

3:41 PM

Ok, not now

I'm tried adding one

Fawn Locke

I think you may be right

Yes, I just needed to reorder my arguments. Thanks.

Adám

(⍺ ⍵⍵ 1⌷⍵) ⍵⍵ 2⌷⍵
(2⌷⍵) ⍵⍵⍨ (⍺ ⍵⍵ 1⌷⍵)
(2⌷⍵) ⍵⍵⍨ (1⌷⍵) ⍵⍵⍨ ⍺
⍵⍵⍨/((⊂2 1)⌷⍵),⊂⍺

Fmbalbuena

Mobile + Chrome = Not Great Experience D:

Fawn Locke

That makes sense to me in retrospect

Adám

And if ⍵ only has those two elements, then it is ⍵⍵⍨/(⊖⍵),⊂⍺

Fmbalbuena

3:44 PM

By(t)e

Adám

Or something similar to the above. (Might differ if ⍺ and ⍵ are high-rank.

Alex B

3:55 PM

@Adám I just successfully installed the bookmark on Chrome for iOS with your procedure. It works. The problem is that the buttons are so tiny that they cannot be pressed (on an iPhone 8 Plus). I suppose that the minimum form factor to type APL characters is a tablet.

Adám

Even in landscape?

(You should be able to pinch-zoom onto them, but I can imagine that's pretty awkward.)

Maybe the language bar needs a font-size ∧ and ∨.

Alex B

@Adám even in landscape. Pinch-zoom works, of course, but who has time for that?

Adám

Someone also mentioned wanting a minimise button. I just need more hours in the day \○/

Don't get me wrong. I'm happy it is useful to folks.

Alex B

@Adám I suggest making it self-sizing, without manual adjustments. If JS sees a small screen, just makes the font larger.

Razetime

array hacker's keyboard helps a lot

Adám

3:58 PM

CSS can detect DPI, so maybe that.

> iOS

Razetime

oh, sad

hm maybe a mobile style togglable keyboard as a bookmarklet

Adám

A full keyboard?

Razetime

yeah just made in html

Adám

Feel free to PR ;-)

Razetime

sigh I guess I'll have a stab at it

Richard

4:26 PM

Working on this LeetCode problem. Probably a classic.

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

An input string is valid if:
Open brackets must be closed by the same type of brackets.
Open brackets must be closed in the correct order.

Most solution work with a stack. That's new for me but seems a good solution. Is that also possbile with APL or should I think about a more APL'like solution? (whatever that might be, but I'll try to figure something out)

Razetime

i'm sure @rak1507 did this in an array-y manner a short while ago

Richard

And thanks for these puzzles Adam (for who ever didn't see them already)
https://abrudz.github.io/crosswords/1/

Adám

@Richard I usually solve this by removing inner brackets and seeing if anything brackets remain.

rak1507

wrong, it wasn't array-y but it was short (just regex replace all pairs ⍣≡ and check if it equals '')

xpqz

This was one of last year's AoC problems.

Razetime

4:28 PM

stack machine nicely fits into a left to right reduction

Richard

Yes. I'll give that a try.

Razetime

@rak1507 hm maybe it was marshall's bqn thing

Richard

@Razetime Could you elaborate on this one?

xpqz

@Richard This is what I did: strip←'\[\]' '\(\)' '\{\}' '<>'⎕R''⍣≡⊢¨d

Adám

@xpqz ⊢¨ ‽

Richard

4:32 PM

@xpqz lot of new things for me. I'l study this.

Fmbalbuena

@Adám codegolf.meta.stackexchange.com/questions/5243/…

Adám

@xpqz Now there's a neat way to write that without backslashes: '[]' '()' '{}' '<>'⎕R''⍠'Regex'0⍣≡

@Fmbalbuena Yeah, I should get back to handing those out.

xpqz

@Adám There were lots of them, not a single one.

Razetime

consider a left to right reduction where ⍺ is a stack and ⍵ is the next char.
if ⍵ is an opening bracket, concatenate.
if ⍺'s last element matches ⍵, remove the last element of ⍺.
if there is a bracket mismatch, replace the stack with a 0.

Adám

@xpqz ⊢¨ is a no-op.

Fawn Locke

4:34 PM

xpqz

@Adám o yea - prolly a left-over from trying to code fast

Adám

@FawnLocke Yeah, I'm aware that ]defs is broken. It doesn't quite work on a full system either.

Fawn Locke

Gotcha

Adám

Unfortunately, its developer died.

Richard

Thanks all, will keep me busy this evening and probably tomorrow

Razetime

4:36 PM

have fun

Fawn Locke

I'm assuming it's in the dfns library

Yeah, found it.

Adám

It is based on something there, yes, but it gets things wrong:

      f←(+∘1)(1∘+)
      ]defs
f ← +∘1 1∘+

Fawn Locke

Ah, I see

Fawn Locke

4:59 PM

Can you invert (2,⍥⊂/⊢)?

Adám

Did you try?

Fawn Locke

Yeah, got a domain error. Probably because I applied a function before inverting, give me a moment

Adám

In principle it should be invertible.

Heh, I bet nobody has added inversion rules for ⍥

Fawn Locke

Ah, that might be the case

Adám

      'def',⍥⊂⍣¯1⊢'def',⍥⊂'abc'
DOMAIN ERROR
      'def',⍥⊂⍣¯1⊢'def',⍥⊂'abc'
            ∧
      'def'{⍺⍵}⍣¯1⊢'def',⍥⊂'abc'
abc

Razetime

5:02 PM

@Adám do you mind if i remove my remaining bounties? i've stopped rep farming since a while

Adám

@Razetime Not at all. Makes it faster for me to go through.

I need a secretary for mundane things like rep.

Razetime

@Adám consider this as a late hanukkah gift 😛

Adám

@Razetime Thanks! Appreciate that. ○7

Razetime

from 47 bounties to 7 lol

Adám

Yeah, that's much more manageable.

Fawn Locke

5:07 PM

Doesn't seem like n-wise reductions invert either

Adám

Aren't there often infinitely many solutions because they shorten the argument?

Fawn Locke

Yeah, I'd prefer if instead they gave the prototype for the last element(s)

Fmbalbuena

@Adám can you explain me, the ⍞←'W',⎕C'_'⎕R' THERE IS A W'⊢'HERE_ILL,_AY.'

@Adám ~~APL Bar for me?~~ jk but I can't bookmark

Adám

@Fmbalbuena Are you serious?

@Fmbalbuena It replaces underscores with ' THERE IS A W', then lowercases and sticks an uppercase W in front.

Fmbalbuena

I don't understand

Adám

5:17 PM

Try to evaluate these in turn:

'HERE_ILL,_AY.'
'_'⎕R' THERE IS A W'⊢'HERE_ILL,_AY.'
⎕C'_'⎕R' THERE IS A W'⊢'HERE_ILL,_AY.'
'W',⎕C'_'⎕R' THERE IS A W'⊢'HERE_ILL,_AY.'

Fmbalbuena

' THERE IS A W'⊢'HERE_ILL,_AY.' gives

Unknown

Adám

That's not how things bind.

Fmbalbuena

@Adám what is ⊢

Adám

'_'⎕R' THERE IS A W' is a single function because ⎕R is a dyadic operator.

@Fmbalbuena I just taught it to you.

Fmbalbuena

@Adám Help me

Adám

5:20 PM

Look in the transcript. It is very simple.

Fmbalbuena

@Adám ?

Adám

yesterday, by Fmbalbuena

@Adám ⊢ seems doing nothing?

Fmbalbuena

Ok

Wait why I need?

⍞←'W',⎕C'_'⎕R' THERE IS A W'⊢'HERE_ILL,_AY.' gives ⍞←'W',⎕C'_'⎕R'HERE_ILL,_AY.'

@Adám ^

Adám

@Fmbalbuena ⎕R needs 3 things, what to replace, what to replace it with, and the text to be altered.

Fmbalbuena

I don't understand

Adám

5:25 PM

what_to_replace ⎕R what_to_replace_it_with ⊢ text_to_be_altered

Now I need to play with my children.

Fmbalbuena

@Adám ok

pmikkelsen

6:20 PM

Hey, is it possible to change the font in RIDE?

Kamila Szewczyk

i don't think so

it seems hardcoded

https://github.com/Dyalog/ride/blob/28f972e387c18ac13fbbf80f9e82595a6065fc1a/style/less/layout/fonts.less
https://github.com/Dyalog/ride/blob/6978b01c3181d1a615e870da58fb33203518372e/style/less/themes/base.less

pmikkelsen

Hm okay, thanks

Fmbalbuena

6:51 PM

Hey, Who are APL Experts?

rak1507

@Fmbalbuena please just ask your question

Fmbalbuena

@rak1507 I want to know who are APL experts

Alex B

@Fmbalbuena ⍬ LOL

Fmbalbuena

@AlexB What is that joke?

Adám

@pmikkelsen I believe @RikedyP found a (hacky) way to do it, since RIDE is just HTML+CSS+JS. Meanwhile, go express your support for github.com/Dyalog/ride/issues/611 as that may increase the chance of this feature being added.

pmikkelsen

7:00 PM

@Adám I also just went in to the folder in my RIDE installation and replaced the Apl385 font files with SAX2.ttf and it seems to work.

Fmbalbuena

@Adám tell me a APL joke and explain

Alex B

@Fmbalbuena Zilde (there are no APL experts)... it was a joke...

Adám

@Fmbalbuena PaulMansour, Morten, Brian, JeffZeitlin,… Me, I guess, but I have much less experience than those.

@pmikkelsen Without changing any files? Or did you rename SAX2?

Fmbalbuena

APL joke

@Adám can you remember/think one?

Adám

@Fmbalbuena ¨∊∪←=⊢2⍝∧?* Each member of the union gets equal right to comment and question power.

@Fmbalbuena You don't need to ping me twice. I answer requests as quickly as I can.

Fmbalbuena

7:05 PM

Ok, another?

Adám

>⍝ Help me, Obi-Wan Kenobi, you’re my only hope

Fmbalbuena

@Adám explain?

Adám

Have you ever seen Star Wars?

Fmbalbuena

@Adám maybe

Adám

You don't know if you've seen Star Wars‽

Fmbalbuena

7:09 PM

@Adám I have seen Star Wars. But I probably forgot.

Adám

OK, so in Star Wars, there's a robot that looks like ⍝ which plays back a recorded holographic message. The holographic projection looks like >. The message is "Help me, Obi-Wan Kenobi, you’re my only hope".

Hmmm another?

⍴⍴⍴'your boat'

⋄5 ¨∊∪←=⊢2⍝∧?*

@Fmbalbuena
SYNTAX ERROR: The function requires a left argument
      5¨∊∪←=⊢2
           ∧

Fmbalbuena

7:11 PM

@Adám explain?

Shape Shape Shape your boat?

Adám

⍴ is a Greek Rho, which is pronounced very close to "row".

pmikkelsen

@Adám i renamed it to the name of the file I deleted :)

Adám

Row, Row, Row Your Boat

"Row, Row, Row Your Boat" is an English language nursery rhyme and a popular children's song. It can also be an "action" nursery rhyme, whose singers sit opposite one another and "row" forwards and backwards with joined hands. It has a Roud Folk Song Index number of 19236. Bing Crosby included the song in a medley on his album 101 Gang Songs (1961). Crosby also used the song as part of a round with his family during his concert at the London Palladium in 1976. The performance was captured on the album Bing Crosby Live at the London Palladium. == Lyrics == The most common modern version is often...

Fmbalbuena

@Adám last one?

Adám

@pmikkelsen Maybe add a section to apl.wiki/Fonts explaining how to do that hack?

@Fmbalbuena bb∨~bb to be or not to be

Fawn Locke

7:14 PM

heh

pmikkelsen

@Adám good idea, but I'm off my computer for today, so I'll do it next time I turn it on

Fmbalbuena

@Adám ?

Adám

@Fmbalbuena Have you heard about Shakespeare's theatre piece called "Hamlet"?

To be, or not to be

"To be, or not to be" is the opening phrase of a soliloquy given by Prince Hamlet in the so-called "nunnery scene" of William Shakespeare's play Hamlet, Act 3, Scene 1. In the speech, Hamlet contemplates death and suicide, bemoaning the pain and unfairness of life but acknowledging that the alternative might be worse. The opening line is one of the most widely known and quoted lines in modern English, and the soliloquy has been referenced in innumerable works of theatre, literature, and music. == Text == This version preserves most of the First Folio text with updated spelling and five co...

Fmbalbuena

Ok

user

Here you'll find all the APL jokes you want

Fmbalbuena

7:24 PM

@user I read everything

@Adám a task

Fawn Locke

⋄ (,⍨∘(⊢/)⍨'∨~',⍥⊂≢,∪)'bb'

TryAPL

@FawnLocke
┌───┬──┬───┐
│2 b│∨~│2 b│
└───┴──┴───┘

Adám

7:50 PM

@Fmbalbuena Write a function that, given a numeric list, adds 2 to every element of the list except the first one. E.g. F 3 1 4 1 5 → 3 3 6 3 7

Fmbalbuena

CMC: taking a list, move left and right example [1, 2, 1, 2] gives [1, 2, 2, 4, 1, 2] because

   [1, 2, 1, 2]
          v  -  v
       v  -  v
    v  -  v
 v  -  v
[1, 2, 2, 4, 1, 2]

@Adám ^

Adám

@Fmbalbuena 0 0∘(,+,⍨) : ⋄ F←0 0∘(,+,⍨) ⋄ F 1 2 1 2

TryAPL

@Adám 1 2 2 4 1 2

rak1507

same as what I had

Fmbalbuena

⋄ F←0 0∘(,+,⍨) ⋄ F 1 1 1

TryAPL

8:02 PM

@Fmbalbuena 1 1 2 1 1

Adám

Longer, but more beautiful solution: 0 0∘,+,∘0 0

Fmbalbuena

@Adám CMC: infinite sequence starting with [1] and move left and right.

Adám

So

1
1 0 1
1 0 2 0 1
1 0 3 0 3 0 1
1 0 4 0 6 0 4 0 1

Fmbalbuena

@Adám exactly

Adám

@Fmbalbuena Try it online!

Fmbalbuena

8:06 PM

without integer overflow

rak1507

@Adám ah nice, pascals triangle

Fawn Locke

That's cool

Fmbalbuena

@Adám and ignore zero

Kamila Szewczyk

@Adám thrilling

Adám

@Fmbalbuena Try it online!

Kamila Szewczyk

8:13 PM

do we really have that many high-level APL wizards here

Adám

I guess we could add Aaron Hsu (arcfide) and Marshall to the "young wizards" list.

rak1507

and dzaima

Fawn Locke

Yeah

Adám

Has dzaima ever written any APL code that went into any sort of production?

Fawn Locke

For some definition of production

rak1507

8:16 PM

has marshall? (also I don't think that makes someone good at APL it makes them good at writing production software)

Wezl - a cautionary tale

code golf is production prove me wrong :P

Adám

I'm pretty sure he has. Certainly J code.

Kamila Szewczyk

production code is usually of much worse quality than other code

user

Really?

Kamila Szewczyk

lack of time pressure, limited backwards compatibility requirement

yeah.

that's the case for MySql

open source databases are usually much better and preffered over clunky MySql

Master Quiz

8:18 PM

Where is this suppose to work? On RIDE it seems to do nothing on RIDE and on the IDE it opens a windows, but it gives this error message.,
1+1
2
VALUE ERROR: No result was provided when the context expected one
P[0] P←{SelText⊢←2⍴⊂1,⍨≢Text⊣Text,←{0=⎕NC'⎕SE.Dyalog.Out.Filter':↓⎕FMT ⍵ ⋄
⍵ ⎕SE.Dyalog.Out.Filter ⍬ 1}⍺}

Kamila Szewczyk

just look at enterprise dyalog code lol

Adám

@MasterQuiz Requires 18.2

Kamila Szewczyk

news.ycombinator.com/item?id=18442941

that's a nice read

Master Quiz

@Adám Why is it useful for you? Like, if I have to save some code I put it in a file, I don't go search for it in the session...

@Adám Where can I download it?

Fawn Locke

What makes someone an expert in your eyes?

@anyone, really

Kamila Szewczyk

8:21 PM

appropriate amounts of knowledge, insight and experience

Adám

@MasterQuiz Dunno, really. I guess it reminds me what I was working on, I guess. I don't look much at it, but it doesn't bother me either.

Kamila Szewczyk

experience, as in "I've already worked on the X problem and I came up with the Y solution"

Adám

@MasterQuiz You can ask for access to the beta programme or wait a couple of weeks. But you hardly need it. I already published a cross-platform alternative that works with previous versions. It was just an experiment.

Kamila Szewczyk

for any X loosely related to the subject of study

Adám

When I was little, I kept my session clean, but I was using APL*PLUS which had nice default keystrokes for removing text.

Master Quiz

8:26 PM

@Adám Didn't understand what should I do. Wait?

Adám

What are you trying to achieve? A separate output pane?

Fawn Locke

monadic ⊆ is actually pretty useful for managing highly recursive structures

Master Quiz

@Adám I tried both. But one was simply dockable

Adám

@FawnLocke I mostly write utilities, tools, etc. That's why I lobbied (successfully!) for it.

Fawn Locke

:)

Adám

8:29 PM

@MasterQuiz Ah, I think I can modify the existing one to be dockable on Windows.

Kamila Szewczyk

8:46 PM

@Adám small question: assume i have an operator A

i want to apply it stacked N times

Adám

Yep, another useful hyperator.

Kamila Szewczyk

so for instance, {2×⍵}A 5 is A applied once, {2×⍵}A A 5 is A applied twice

or with parens for clarity, ({2×⍵}A) A 5

Adám

You want for operators what ⍣ is for functions?

Kamila Szewczyk

sort of

Adám

I can't think of any other simple way to do it than using ⍎

Kamila Szewczyk

8:49 PM

i think i can

Adám

Oo?

Kamila Szewczyk

hang on

yep :)

did it

i know i know

tried to fix it

      {2×⍵}{⍵⍵=1:⍺⍺ D ⍵⋄((⍺⍺ D) ∇∇ (⍵⍵ - 1)) ⍵}1⊢5
2
      {2×⍵}{⍵⍵=1:⍺⍺ D ⍵⋄((⍺⍺ D) ∇∇ (⍵⍵ - 1)) ⍵}2⊢5
0

there, first and second derivatives

rak1507

that hardcodes D though

Kamila Szewczyk

i never asked for a general solution

I wanted to apply my operator and nothing else

but you could solve this with a nested dop.

Adám

(D)ops can't take operators as operands.

Kamila Szewczyk

8:51 PM

truuuueee...

Adám

Even BQN and J would have trouble, I think.

Master Quiz

@Adám How? The 'Zero Footprint' thing?

Adám

Yes.

Master Quiz

@Adám In the docs I'm not finding how to do it...

Fawn Locke

     (('h',⍕∘≢)U⊃@(<\≠)' '∘(≤\⍤≠⊆⊢))
   h,  ∇ç ∘≢   ∇U ⊃ @  <\ ≠    ∘   ≤\ ⍤≠ ⊆⊢

TryAPL output I'm assuming it's because of the U, sorry to spam this btw

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