The Nineteenth Byte

I like how it admits to being a bot

it's refreshing

OldSandboxPosts

1:00 AM

Sandbox posts last active a week ago: Sleep Forever, Chinese color mixing, The next popcount, Tableing in 3 operations

New Posts

3:16 AM

0

Q: Meta-cat program

Write a program or function that takes input and outputs/returns a full program (in the same language) that outputs said input. Note that the input may contain any printable ASCII character or newline (AKA 0x20-0x7f and 0x0a). However, the input will not have trailing whitespace nor preceding whi...

3:26 AM

I have now joined the 30k club, I decided

5:53 AM

@mousetail in your ><> explanations, the "s don't show in the top one

I just noticed that

also, I know you`re already aware it displays glitched on some devices, but it also breaks on samsung internet on my watch :p

As long as it works in the Nintendo DS browser I'm happy

5

that`s all you can really aim for in life :p

7:00 AM

@NewPosts wow some delicious butter! Unfortunately, I have no toast to spread it on :(

7:35 AM

Hello!

7:49 AM

@Simd hi

How things?

8:24 AM

I am wondering if anyone is working on my challenge....

10:13 AM

Why the

user, The past (for me)

147 2 20 68

code-golf math string sequence number array decision-problem

has only 147 reputation but has very many posts that are 5+?

Bounties

oh understand

17650 rep worth of bounties to be precise

codegolf.stackexchange.com/users/95792/…

whoa

That's nothing :-)

10:25 AM

@Adám PR

PR? Oh, got it. Yes.

@Adám Nice! ;)

PR?

I do not got it

@lyxal When the person praise themself

urbandictionary.com/define.php?term=PR

@Petəíŕd Oh, that's not what I meant/understood. I hand out these bounties for Public Relations reasons, i.e. as a form of advertisement, incentivising people to golf in APL.

10:30 AM

Position changed. Now I don't understand, lol

A: List of bounties with no deadline

Part of my job is to promote APL. One of the ways I do that is by using APL on this site, as it gives it more exposure. However, it can of course also get more exposure if others use it. So I give bounties to APL answers:

21

Disclaimer: This bounty was posted by a person whose job is to promote APL. 50 – 500 rep for an APL answer I will reward 50 rep if all of the following conditions are met: The answer is in Dyalog APL Classic/Unicode/Extended/Prime, APL2, APL+, APLSE, GNU/APL, Sharp APL, sAPL, SAX, NARS, APLX, A+...

11:07 AM

Is that you Elon Musk? @lyxal

Is that you Elon Musk? @Fatalize

2

@Adám …damn it

didn’t think this through

But my logo is not exactly an X though

Neither is Twitter's. It is 𝕩

(Aside: People keep saying it isn't exactly 𝕏, which is true, since it is exactly 𝕩 — in some fonts)

11:24 AM

@Fatalize well you see I'm beginning to think the answer is yes. We both like the letter x, have a blue icon next to our usernames, can edit any of our messages at any time and dislike birds

lol

@lyxal "StackExchange now offers to have a diamond next to your nickname for only $8/month"

How much for a spade?

@mousetail We haven’t thought of all these details yet so we’ll come up with them as we go

If I had a nickel for every situation I've been in where a twitter blue $8 verification mark joke on SE could be made, I'd have two nickels, which isn't a lot but it's weird that it's happened twice

11:32 AM

I’m not up-to-date with the state of the art of memes on TNB

sorry

the first time

This is the second :p

Maybe SE can jump on the bandwagon: x.ai

Don't give them ideas :p

"The goal of xAI is to understand the true nature of the universe."

slightly ambitious

@Adám I can only imagine the SO CEO will be announcing all sorts of ai bs on Thursday

11:36 AM

@Adám The twitter bird logo at the bottom of the page… lol

Rename SE to SX — StackXchange

tbf that makes more sense than renaming Twitter to X

Just change all the letters in every alphabet to x

x xxxx xxxx xxxx

@NewPosts I want to see someone do this in Trilangle because of the aforementioned codegen-is-difficult

The hard part is really going to be handling whitespace

A: Sandbox for Proposed Challenges

11:57 AM

The worst is when you run out of monospaced fonts and have to use variable-width variables.

Sandbox Posts

12:34 PM

0

We are only using 0.000016212% of UTF-8, write a program that can handle the full 100% The UTF-8 encoding theoretically allows for encoding 68719476735 characters, only 1114112 of these are valid codepoints (due to the limitations of UTF16). You goal is to write a function or program that takes a...

New Posts

1:04 PM

0

Q: Make a k-skip-j range

On the Mathematica StackExchange, 100xln2 asks: I need a list of integers […] The list contains integers and is characterized by [three] parameters, lets call them k and j [and listmax], which should be variable. If k=1 and j=1 then the list would look like this: {1,3,5,7,9,11,....until listmax}...

code-golf sequence

1:31 PM

> Move the top elemnt of the stack back 2

@mousetail typo spotted

I've been cursed

I mostly hate needing 12 fcn bytes of stack manipulation just to get the 3 values I need on top of the stack in the right order

I feel that

1:56 PM

@mousetail and that's why I use dedicated golfing languages :p

There is no fun in that though

the fun comes from saving energy not having to hate the 12 extra bytes :p

Unsafe vehicles, hills, and philosophy go hand in hand.

@lyxal Saving the bytes is only fun if they exist in the first place

@mousetail Disagree, it's more fun to get a clever 1 byte save in Jelly þan it is to save 10 in Pyþon/Java by cutting down on whitespace

2:03 PM

Finding a more efficent way to organize the stack in ><> that lets you make your stack manipulation shorter is very satisfying though

A -1 byte shave is even more satisfying in a golfing language

I think the most interesting Swift answer I've seen abused the fact that lambdas and actual functions use different calling conventions. Because the calling conventions are different, it can't TCO, and therefore mutual recursion overflows the stack very easily

@lyxal Especially when it lets you beat Vyxal and Vyncode :P

Yeah yeah you and your fancy 1 indexing

:p

At least vyxal has a 2k+ elo :p

I'm curious where Trilangle would fall but I've intentionally only done numeric ones because it's shorter there. Any array manipulation will be painful

2:08 PM

I feel using a language meant to golf completely defeats the purpose of golfing

@lyxal I'll just point out þat Jelly hasn't been updated for 5 years :P

Okay boomer

Jelly be in the golflang nursing home

@mousetail Tbf, I'm a lot more selective when answering wiþ a golfing lang, because þe challenge needs to be actually interesting enough for me to boþer wiþ Jelly in þe first place

I forgot I had þe þorn userscript enabled :P

Why are you sing the weired unicode substitutions?

hyper-neutrino

"thorn" written with the thorn looks sus

also damn I haven't checked here in a while and I missed lyxal becoming mod, congrats

2:11 PM

thanks lol

@cairdcoinheringaahing the real question is why you had it enabled in the first place

Ginger

careful, that's a bit of a thorny subject

@lyxal I reinstalled my userscripts when I got a new laptop

Ah

Jul 21 at 23:23, by caird coinheringaahin g

@RydwolfPrograms Oh, so I should nuke this bot, good to know

Looks like you got it in the last 3 days then :p

@cairdcoinheringaahing You should use ð for voiced th ðough

Eh.

It was never consistent in Old English

Broadly speaking, edh was used between vowels and thorn at the edges of words, but even that's only a general trend and not a hard rule

2:20 PM

Just discovered I even have ∂ on my keyboard layout

2:36 PM

@lyxal Yep, 2 days ago :P

3:16 PM

codegolf.stackexchange.com/a/263321/3852 I think this is a snippet, right?

I think it needs either ⎕← to be a full program or {} to be a function. It looks kinda like they had it in {} and copied only the } and then also didn't count it to their byte total.

@Lynn I had a dfn and then edited to what I guess counts as a snippet

how do I revert an edit?

okay I found the button, back to 12 it is

OK, gotcha! I see a nice byte save. Monadic ⍸ has a behavior I wish Jelly or Vyxal had, but I don't think they have it: ⍸3 5 is 1 1 1 2 2 2 2 2.

I'll never learn those weird extensions Dyalog does to boolean functions

@Lynn sorry, I don't have access to an interpreter for a while, I assume the save is something like indices 1 = omega reshape índices alpha?

Yep, that's right :) Ooh, you can then make it a tacit function to get something really short.

3:36 PM

indices 1 = reshape beside indices? (with arguments swapped of course)

I think this ⍸ behavior might originally be a K thing, where it's called &. J's I. does it too. Jelly used to have it, and it was called O, but it got replaced by T which doesn't do the duplicating, and O is ord now

@RubenVerg Yep, that's it

@Lynn /⍳⍴ is an old APL idiom, predating J and K by decades.

@RubenVerg I can't see the suspect version, but being that you only use ⍺ and ⍵ once, you could replace them with ⎕. Output is implicit.

@Adám that's what I'd done, but I can see how it would count as a snippet. I now have the tacit version up

@Lynn thanks for the help!

@RubenVerg Ah, ok, but that's commonly done. It is a valid full program tradfn body or simply REPL program, i.e. you can pipe it into the interpreter and it just works.

3:56 PM

good to know for the future thanks

@lyxal btw when I edit an answer with luminespire am I meant to use the tool again to regenerate the block? for the whole metadata thing

I don't know if APL has special conventions on the site, but we don't allow function bodies return x+1 or REPL programs for x in range(9):x*x in Python, right?

We allow anonymous functions, though, and all a tradfn body needs to run is a name.

What's the syntax for giving the body a name?

if there isn't previous consensus on this I kinda side with @Lynn here - "you can put it in a tradfn" isn't really an argument because it isn't inside one

@Lynn Just put the name on a line before the code.

4:06 PM

unless there is a Dyalog equivalent of node -p, which I think is allowed?

I don't think an official consensus (meta post) has ever been made, but I've certainly posted tradfn bodies/REPL code for years.

if the law doesn't say you can't...

You can encode 16640 in the 1 and 2 byte spaces combined.

*16640 chars

print(int(input())**2)   # ⎕←⎕*2
def f(x):return x**2     # ∇ r←f x ⋄ r←x*2 ⋄ ∇
lambda x:x**2            # {⍵*2}
2 .__rpow__              # *∘2

return x**2              # r←x*2
x**2                     # x*2

int(input())**2          # ⎕*2

ctrl-K for code block

4:21 PM

I tried to make a fair comparison, but of course Python is not APL :) Anyway, in Python, the first four are allowed, the next two are snippets (invalid), and the last is a full program that doesn't output anything except in a REPL, so we don't normally allow this either, except I guess you could submit it as "Python REPL, 15 bytes"?

Main issue with snippets is that you are not allowed to take input from variables

It makes sense to write up a meta consensus for APL that doesn't invalidate hundreds of APL answers of course. But I was surprised when I ran Ruben's code on ATO and it read two lines of input but didn't output anything.

In that sense it seemed analogous to that last Python program, to me

@Lynn I don't think you can say that r← is equivalent to return

Like Ruben said, if there's a flag to make Dyalog do implicit output, that's ok but it should probably be in the post

I tried to guess at what you mean by "tradfn body".

Python doesn't seem to have it, that's unexpected

or does -c do it even if not documented?

4:25 PM

@Lynn It'd be just x*2 since this is a valid tradfn which prints:

f
x*2

Note that ∇s are not part of a tradfn; they are simply delimiters when a tradfn appears in a larger context.

If I put that in ATO, I get

VALUE ERROR: Undefined name: f
 f
 ∧

1. ATO runs a larger context.
2. ATO runs Dyalog shell scripts, which are very different.

I think the question here is

Shell scripts are very much like the REPL (when the REPL is in multi-line input mode), but with the crucial difference that there's no implicit output.

what configuration set causes Dyalog to take as some form of input the code, run it and output the last result?

4:30 PM

Last result? None. Every non-shy non-assigned result? cat codefile | dyalog

That's interesting, I don't have Dyalog installed right now so I can't play with it, but I wish ATO supported that

@Adám I think this solves the debate, for the same reason node -p is allowed

I did just find this: codegolf.meta.stackexchange.com/a/14232/3852

I forgot about that.

> Tradfn programs are simply one or more lines of code, where input (if needed) is gotten with ⎕ and/or ⍞. On TIO, Tradfn program go in the Code field and the Header field must have a ∇ followed by a name for the program. The Footer field must have a ∇. In the Input field, the first line must have the program's name to call it, and lines immediately after that will be the lines of input, if any.

It sounds like in a sense, Python doesn't have implicit output by default (but the REPL is an exception), whereas Dyalog does have implicit output by default (but shell scripts are an exception)

4:38 PM

And that has +7/−0

@Lynn Right. APL's implicit output is well attested-to, e.g. in various Hello World listings as 'Hello World' without ⎕← and there's the concept of shy results which do not have implicit output, as opposed to normal results which do have implicit output.

And the examples marked ⍝ Invalid, … in this post being invalid is very sensible to me :+1:

Earlier I thought you were implying x+.×y is allowed too, because it's a tradfn body. I guess the actual meta is you don't have to count the tradfn header if it's only a name f, but you do have to count it if it's like x f y.

A: Sandbox for Proposed Challenges

Yes. Sorry, I should have clarified that x*2 was just placeholder code.

Sandbox Posts

5:49 PM

0

First attempt at a question. Feedback appreciated. Calculating Complete Graphs The above picture shows a complete graph with 7 vertices. According to Wikipedia, "a complete graph is a simple undirected graph in which every pair of distinct vertices is connected by a unique edge." Today, we're g...

noodle man

6:08 PM

CMC: Given positive integers N and B, convert N to a list of digits in base B, but each digit should be represented as a unary number

kinda boring challenge but whatever

How do we represent unary numbers?

@noodleman Extended Dyalog APL, 5 bytes: ⊤↑¨0⍨ Try it online!

6:24 PM

@noodleman Vyxal, 3 bytes: τ×*. Input base number, then a newline, then the number to convert.

6:59 PM

@noodleman Pip -p, 7 bytes: 1X:aTDb

7:35 PM

CMC: print something similar to CMC.

8:01 PM

@Iamkindofalanguagedev PHP: CNC

@Iamkindofalanguagedev 1000

(polyglot)

@Iamkindofalanguagedev Python: print("something similar to CMC.")

is there any way I can run a mathematica script for more than a minute? Does anyone here have access to mathematica?

Try octave?

8:16 PM

hmm.. I think that is more similar to matlab than mathematica

I just want to run codegolf.stackexchange.com/a/263302/116117 for longer

I'll just have to wait for the first open source answer

so tempting to add a bounty.... :)

8:32 PM

Why didn't you specify the language had to be free? It would be a reasonable restriction

@mousetail I thought it was implied by the fact that I said I would test the code

"I will try your code with inputs n,d
in increasing order until it takes more than 1 minute to run on my PC. "

Nothing is implied unless you state is explicitly

@mousetail I guess so. I don't mind but will be happy when the open source answers start coming in

> Input 9,4 -> [10, 21] # An as yet unknown value between 9 and 21, inclusive.

is it 9 or 10?

one of those is a typo

@Bbrk24 thanks. Fixed

9:03 PM

@Bbrk24 are you working on a submission?

noodle man

@noodleman TypeScript's Type System, 140 bytes:

//@ts-ignore type M<A,B,T=[]>=A extends[...B,...infer I]?M<I,B,[...T,1]>:[T,A];type B<N,R,D=[],X=M<N,R>>=N extends[]?D:B<X[0],R,[X[1],...D]>

@noodleman How do I run this? I clicked Run but I don't see a result anywhere.

How do people set up a chat room linked from a comment?

9:24 PM

agree to the system's suggestion

@DLosc People tend to handle TS types in one of two ways: for boolean problems, compile vs doesn't compile; for other problems, mouse over the thing and see what the language server renders

In this case:

There's at least one thing I did where it was decided that wasn't allowed, so I just made it always error and embedded the answer in the error message

noodle man

yeah i should have added one of those // ^? comments to my playground link but i forgor

also it can output a list of digits in decimal for 10 bytes by replacing [X[1],...D] with [X[1]["length"],...D]

9:40 PM

@Bbrk24 Ah, okay, cool

@Bubbler I'm thinking of forking your Piet interpreter for a new 2D language I'm designing. If I do, how would you like to be credited?

10:08 PM

@RubenVerg that's right. You paste it into the import box and it imports everything as you had it. It even tries to import explanations without metadata

10:30 PM

what does move the top element of the stack back 1 mean in ><>, as in $?

is it moved in the codebox?

Iirc it means [a, b] --> [b, a]

so it's a swap instruction

ah ok, thanks

"swap the top two items of the stack" would be a lot clearer

@Bbrk24 Well semantically speaking it should be

10:34 PM

@Bbrk24 yeah, but you also have @

I'd guess mousetail was trying to make their descriptions consistent

I see

@c-- that's what I'd call shift

Or rotate

I prefer rotate