The Nineteenth Byte

CMP: Would people find it helpful if I made a Jelly tutorial video series or has everyone who wants to learn Jelly already learned it from tutorial page or JHT? :P

user202729

I hate watching video. Reading is easier. So, no.

HyperNeutrino

ok :P

I find videos hard to follow along sometimes because half the time they're too slow and the other time too fast but some people find them useful

Mr. Xcoder

Maybe we could write our own (JHT) Jelly documentation pages and newbie-friendly hints, since the ones in Jelly's wiki are quite hard for new users to follow.

Fatalize

3:13 PM

@HyperNeutrino I have made a video intro to Brachylog, if you want an example

HyperNeutrino

that was mainly where I drew inspiration for the idea :D

Fatalize

ninja'd I guess then...

HyperNeutrino

:P

Mr. Xcoder

lol

HyperNeutrino

@Mr.Xcoder that's a pretty good idea. I might also get around to making an improved documentation page that has better searching

Fatalize

3:14 PM

I thought about doing more but it's difficult to find a proper learning path

HyperNeutrino

and also copy-pasting symbols using keyboard shortcuts because I don't like using my touchpad xD

Fatalize

and I'm not sure there's interest for it anyway

Mr. Xcoder

@Fatalize I find one thing hard in Brachylog: How to get rid of its declarative style when it's not needed. For instance, if I want to output the alphabet, what should I do in order to prevent it from printing true.?

Adding Z = as an argument didn't do it :P

Pavel

@Fatalize Most places have free refills though

Fatalize

@Mr.Xcoder this?

I guess we would need the code you tried to see why it didnt work

Mr. Xcoder

3:18 PM

@Fatalize Oh... Dang I had an extra =. I always added Z= instead of Z or OUTPUT... That's why it never worked... Thanks and sorry :C

Fatalize

Oh

Mr. Xcoder

I am dumb.

Fatalize

It seems like input and output has always been confusing

No you're not, Erik and LeakyNun had the same difficulties understand inputs and outputs

I'm not sure how to make it clearer

Basically the argument in TIO is for the second variable of th main program

And an uppercase string is a free variable

So really when you put Z you only state that the Output is some variable called Z that is unknown

HyperNeutrino

CMC: Given an integer i and a number n, return any i x i matrix with determinant n. The results don't have to be consistent with the same i and n.

Pavel

Prolog is an odd language, and Brachylog is odder still.

Mr. Xcoder

3:21 PM

@HyperNeutrino test case?

Fatalize

If you know Prolog, Brachylog is fairly easy to understand

Most confusions in Brachylog would not exist if learners knew Prolog

Pavel

I knew prolog at one point, no longer do.

Fatalize

They are often about unification, backtracking and constraints, which are basic parts of Prolog

Pavel

I still basically understand the concepts behind it.

Doesn't make it any less odd though.

Fatalize

@Pavel I relearned Prolog about 2 years after first learning it, to start participating in PPCG :p

Pavel

3:23 PM

Nice

Fatalize

I've actually never used Prolog for any "real" application

Mr. Xcoder

@HyperNeutrino Created :P.

Fatalize

I sometimes use Brachylog to programmatically generate strings for work sometime but that doesn't count

HyperNeutrino

i = 3, n = 3 => 1 2 3 ; 4 5 6 ; 7 8 8
i = 2, n = 5 => 1 5 ; 1 10
i = 3, n =-8 => 0 4 5 ; 8 5 2 ; 0 3 4

^^^yay

Marcus Andrews

any faster way to sort incoming integers, space-delimited on one line?

input()
print(*sorted(map(int,input().split())))

Pavel

3:25 PM

I don't know what you would even use prolog for honestly

It's not particularly good at doing actual work

Mr. Xcoder

@MarcusAndrews faster or golfier?

Marcus Andrews

shortest bytes possible

ruby, python

etc

HyperNeutrino

@MarcusAndrews why do you need to discard the first line and why do you need the *

Marcus Andrews

first line is n, number of entities

i don't use it so i discard

HyperNeutrino

oh ok

Marcus Andrews

3:26 PM

second line is the array to sort, space-delimieted

* to output space-delimited array

splat operator

Fatalize

@Pavel It's good at parsing stuff

Pavel

@MarcusAndrews $_=eval"[#{$_.gsub/ /,?,}]".sort with -p flag.

Marcus Andrews

I can't use flags

Pavel

Why not tho

Marcus Andrews

The interface doesn't allow it

Pavel

3:28 PM

What interface

Marcus Andrews

Codingame

I'm using their codegolf challenges to learn Ruby/Python/shorter code a little better

But the built-in IDE doesn't allow flags

Fatalize

@Pavel NASA uses Prolog for the ISS vocal commands

Mr. Xcoder

@HyperNeutrino Do you want write access to the repo?

Pavel

@MarcusAndrews $><<eval"[#{gets.gsub/ /,?,}]".sort*"\n"

(It should be seperated by newlines, right? Not too good at python)

Marcus Andrews

hm it doesn't like the [

it's all on one line

e.g. input is 4 3 2 5 1

output 1 2 3 4 5

Pavel

3:30 PM

right because its an int array

dur

HyperNeutrino

@Mr.Xcoder sure though I'm not sure how much I'll be able to contribute

Mr. Xcoder

I added you as a contributor

Pavel

@MarcusAndrews eval("[#{gets.gsub/ /,?,}]").sort.each{|i|p i}

HyperNeutrino

cool thanks!

user202729

@Mr.Xcoder Copy the old documentation and then extend it should be a better idea than write them from scratch.

Marcus Andrews

3:32 PM

Have gotta learn this gsub thing

Mr. Xcoder

@user202729 I'll see.

Pavel

@MarcusAndrews General SUBstitute

Mr. Xcoder

(probably I'll use a lot of the old one)

Pavel

First argument is a regex, second is the replacement string

so 'foobarbaz'.gsub(/a/, '!') yields 'foob!b!z'

Marcus Andrews

hm someone got 40, so apparently it can be done shorter

Pavel

3:33 PM

The second argument can also be a block to compute the replacement string

Marcus Andrews

that code didn't work either as it doesn't take in input from the IDE

not sure why

Pavel

gets.split(' ').map{|i|i.to_i}.each{|i|p i} might be shorter but I'm too lazy to count bytes.

Marcus Andrews

mm unfortunately not

that automatically sorts somehow?

Pavel

Wait forgot to sort

crap

user202729

@HyperNeutrino But it can be consistent? | Obviously i > 0?

HyperNeutrino

3:43 PM

consistency is not required and i > 0 yes

user202729

Hm... is there "rightpad" atom in Jelly? Or Enlist? For 1D or 2D array?

ṁ can be useful.

HyperNeutrino

nope, Jelly lacks padding functions

user202729

Extremely ungolfy solution: 12 bytes Jelly Try it online!

caird coinheringaahing

I want to add a bunch of features to Jelly, but the code would look like an ungodly mess of random symbols :P

HyperNeutrino

you can take the G off the end and put it in the display link

user202729

3:49 PM

Actually only 11 bytes because G is for formatting.

HyperNeutrino

also is it just me or is that invalid

shouldn't it be 30000;01000;00100;00010;00001 or am I being dumb again

user202729

Oh sorry

Corrected: Try it online!

HyperNeutrino

nice

anyway gtg o/

user202729

8 bytes: Try it online!

Pavel

@MarcusAndrews Got it in 40, puts gets.split.map(&:to_i).sort.join' '

Marcus Andrews

4:02 PM

ah clever

what's the & mean?

surprised it lets you join with string even though at that point they're all ints

I guess it implicit-casts or something

Pavel

@MarcusAndrews &: is how you reference functions in ruby, since just typing their name calls them.

Marcus Andrews

In this case same as doing something like .map{|x| x.to_i} ?

Pavel

Yep

Pavel

4:16 PM

CMC: Read a number $n from input, and join the next $n lines of input with spaces and output. More input may be supplied than $n, in which case the unneeded input should be ignored. If less than $n lines are supplied, the remaining lines are assumued to be empty but should still be joined by spaces and tacked onto the end.

Alternatively, take n as a parameter to a function, and read n lines from StdIn.

Mr. Xcoder

@Pavel So add a space for each missing line?

Pavel

Yep

Mr. Xcoder

Far too long, Python 97:

import sys
i=int(input());k=sys.stdin.read().split("\n");print(" ".join((k+[""]*(i-len(k)))[:i]))

And 90 in Py 2

@Pavel Can we take input from command line args instead?

Pavel

@Mr.Xcoder sure

I realized the stdin wasn't intresting when I realized it just tacked a $stdin.read.split("\n") to the front of the solution

Mr. Xcoder

82 bytes.

Pavel

4:30 PM

@LuisMendo feature-request multiline strings in MATL

['foo' 10 'bar'] is annoying

'foo
bar'

is better

Mr. Xcoder

Better as a func: def f(k,s):r=s.split('\n');print" ".join(r[:k])+" "*(k-len(r))

And a more interesting 61-byte approach.

user202729

@Pavel Jelly, 5 bytes: Try it online!

^^ Sorry I mistakenly use "code golf submission" mode from TIO.

Mr. Xcoder

@user202729 Seems invalid

user202729

Is there a way to check EOF in Jelly?

Mr. Xcoder

The output should be l1 l2 l3 l4 (with trailing space) for your input and 5.

@user202729 ._. why would one want that, yes there is. Literal Python ŒV

user202729

4:38 PM

@Mr.Xcoder How can you solve the challenge without that?

Erik the Outgolfer

@Mr.Xcoder huh

user202729

(ignore the possibility of take input as argument)

Mr. Xcoder

@user202729 See my method above in Python. It gets all input, splits by newlines, then joins by spaces the input with the elements after index k trimmed (like head), then appends k - number of lines spaces.

I don't even want to try it in Jelly

@EriktheOutgolfer I think you can use literal Python to catch an EOF in jelly :P

Erik the Outgolfer

@Mr.Xcoder if you want to detect EOF, ɠ is not what you should use

Mr. Xcoder

Did I ever mention ɠ?

Erik the Outgolfer

4:43 PM

instead you have to resort to ƈ

ƈ won't throw like ɠ at EOF

AdmBorkBork

@Pavel STDIN in PowerShell is weird, so here's a close equivalent in 47 bytes

Mr. Xcoder

@AdmBorkBork Did you manage to play around with Jelly's quicks?

AdmBorkBork

I did some, still couldn't figure it out.

Mr. Xcoder

Just ask if you want guidance

Q: Is id(0) modulo something considered random by PPCG standards?

Neil

@Pavel C (gcc), 116 bytes

Dennis

4:47 PM

@Pavel Python 2, 33 bytes: exec'print raw_input(),;'*input()

Mr. Xcoder

@Dennis Seems invalid.

Result should be one two three (4 trailing spaces)

Erik the Outgolfer

hmm...

looks like apl should compete fairly well...except from the fact of stdin

J. Sallé

@EriktheOutgolfer I didn't even start trying because of that >.>

orlp

@Neil please don't tell me

that's a switch

in a code golf problem

Erik the Outgolfer

@orlp without weighting any particular way, it clearly says switch, so it's definitely a switch

:p

Neil

4:52 PM

@orlp OK, I won't

Dennis

@Mr.Xcoder That depends heavily on the something.

@Mr.Xcoder Ugh.

Neil

I guess I could eliminate it if the input was guaranteed not to contain tabs etc.

Mr. Xcoder

CMC: Output the nth term of this sequence: 1, 0, 1, 2, 4, 1, 6, 8, 0, 1, 2, 4, 6, 8, 1, 0, 2, 4, 6, 8, ... (1 followed by 1 even digit, 1 followed by 2 even digits, ...). The even digits must start from 0, and must appear in cyclic order. Choose either 0 or 1-indexing. Alternatively, you may output the first n terms.

Erik the Outgolfer

@Dennis yup otherwise you could just do ⁸;ƈ$ÐLỴż⁶ :p

@Mr.Xcoder not sure if that's more appropriate as a cmc or as a main?

Mr. Xcoder

@Dennis Oh yeah of course, but id(0)%17 for instance? Thanks anyway

@EriktheOutgolfer I think I'll move it to Main

Luis Mendo

4:56 PM

@Pavel I know :-( But that's as per Matlab / Octave. I had one idea to solve it, but turned out to be too complicated

Erik the Outgolfer

@LuisMendo wait huh

why can't you just so something like

Adám

@Pavel Can we wait indefinitely until n lines have arrived?

Erik the Outgolfer

'This is a newline:
'

Mr. Xcoder

How does Cyclic Sequence of even digits, with odds in between sound? (for the title)

Erik the Outgolfer

I'd recommend sandboxing first btw

Mr. Xcoder

4:58 PM

Already sandboxing.

Erik the Outgolfer

you might find out it's actually a dupe :D

Adám

@EriktheOutgolfer ⍞

Mr. Xcoder

@EriktheOutgolfer I don't think so... But well, we all know Peter :P

Erik the Outgolfer

peter has an amazing ability to recognize dupes most of us wouldn't

the second part of this sentence is a reason to sandbox on its own :p

Mr. Xcoder

I know, that was a compliment

Erik the Outgolfer

5:00 PM

@Adám how do you input newlines into that

Mr. Xcoder

What do you think about this description:

> It consists of runs of even digits, of increasing length which are interleaved with the digit 1. The even digits are always in cyclic order, which means that they appear in ascending order until we get an 8. Then, we cycle back from 0.

Dennis

Are you sandboxing the sandbox post?

Mr. Xcoder

@Dennis Good point...

Erik the Outgolfer

@Dennis what sandbox post? it's not yet one afaik

Dennis

It's currently being sandboxed here.

Pavel

5:08 PM

@Dennis well, people will actually see it here.

Mr. Xcoder

Yeah I kinda used TNB as a Sandbox for the Sandbox answer, which is a sandbox for main :P

Dennis

Question: do we have a vanilla Cartesian Product challenge? There's Cartesian product of two lists, but it's a bit different if more than two lists are involved.

Pavel

I disguise my use of TNB for sandboxing with CMCs.

Erik the Outgolfer

@Dennis don't think so

Adám

@EriktheOutgolfer You don't need to. The challenge is to get lines. Each call to it gets a single line. {⍞}¨⍳n gets you a vector of n lines.

Mr. Xcoder

5:14 PM

Sandboxed. Any help with the description is welcome

Erik the Outgolfer

@Adám sure, just asked if there's a way to input newlines as well...or how to eof

Pavel

@Dennis Well, you know how it is. Most effective dupe-checker out there is the "Post title" field to the question-asking form.

Adám

@EriktheOutgolfer No, every newline will cause ⍞ to return.

@EriktheOutgolfer Well, you can keep looping until the input ends with a ⎕UCS 0.

CMC:

RC4 stream cipher in one tweet: KSA=(k)=>{S=[];j=0;for(i=0;i<255;i++){S[i]=i}for(i=0;i<255;i++){j=(j+S[i]+k[i%k.length])%256;b=S[i];S[i]=S[j];S[j]=b}return S} PRGA=(S,i,j)=>{i=(i+1)%256;j=(j+S[i])%256;b=S[i];S[i]=S[j];S[j]=b;K=S[(S[i]+S[j])%256];return[[S,i,j],K]}

Tweeted by kaepora on November 8, 2017 at 4:07 PM

Erik the Outgolfer

@Adám looks like javascript. that's all I know.

Pavel

If ←⎕ reads from stdin, what does ←⍞ do?

Dennis

5:17 PM

Not sure about the rest, but i<255 is definitely wrong.

Erik the Outgolfer

@Pavel ⎕ evaluates a line, ⍞ return an unevaluated string

Pavel

Ah

Adám

@Dennis Nicely spotted. My APL reply doesn't have that bug.

Mr. Xcoder

So the shortest tweetable RC4 stream cipher?

Adám

@Pavel Actually, ⎕ is a little bit more than ⍎⍞ (execute STDIN), in that it will send a short prompt to STDERR, insist on an answer, allows system commands, and allows the user to break out.

Pavel

5:20 PM

Cool

Adám

@Mr.Xcoder "tweerable" is redundant. The shortest possible is tweetable.

Erik the Outgolfer

@Adám in this case, yes

Pavel

Is Squad (⌷) just a pun on Quad (⎕) or is there another reason behind the name?

I don't think I've ever seen Squad actually used.

Adám

@Pavel squished quad

@Mr.Xcoder More specifically: Total byte count of two functions with the same I/O structure as the tweet's.

Pavel

The description for Squad says "Materialize" and I can't figure out what the example doing.

Luis Mendo

5:24 PM

@EriktheOutgolfer It has to do with the fact that input is interactive and as in Matlab. That means that an "enter" key finishes the input. I thought of taking the unevaluated input when "enter" is pressed, seeing if the input so far is valid (if the closing quote is present), and else inputting another line.

Quotes within the string are no problem (they are escaped by duplicating). But the problem is that a single, unmatched quote may appear (and it means transpose). Handling that is diffcult

Adám

@Pavel I tend to use ⊃ more, and they are often equivalent. However, ⌷ can index high-rank arrays. E.g. 2⌷matrix is the second row, and 2 3⌷matrix is the third element of the second row.

Maltysen

@Adám well for one, u can set 256 to a variable

that'll take off two bytes

Pavel

@Adám Wow, the description for Squad is unhelpful. I couldn't tell that anything is being indexed in the examples.

Adám

@Pavel Monadic ⌷ is an identity function (no-op) for most things, but for .NET collections it turns them into vectors of .NET objects, and for a class with a default property it returns that.

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

The cyclic sequence of even digits, with odds in between Consider the following sequence: 1, 0, 1, 2, 4, 1, 6, 8, 0, 1, 2, 4, 6, 8, 1, 0, 2, 4, 6, 8, 1, 0, 2, 4, 6, 8, 0, 1, ... The even digits start from 0 and are grouped into runs of increasing length. They are arranged cyclically, meaning ...

Mr. Xcoder

5:27 PM

@LuisMendo Do you think binary or binary-matrix would be suitable, now that you have tiling?

Adám

@Pavel Which description are you looking at? TryAPL/IDE Language bar or the full docs?

J. Sallé

@Adám I think he's looking at the REPL description?

Luis Mendo

@Mr.Xcoder I think binary, yes. Thanks

Adám

@Pavel Look here instead

@Maltysen I don't see how that's going to save anything.

New Main Posts

4

Q: Tiling in one dimension

The purpose of this challenge is to determine if a collection of one-dimensonal pieces can be tiled to form a continuous chunk. A piece is a non-empty, finite sequence of zeros and ones that starts and ends with a one. Some possible pieces are 1, 101, 1111, 1100101. Tiling means arranging the p...

Adám

5:31 PM

@noidd @kaepora We do love a challenge - yes we can do it in 123 characters: KSA←{S⊣⍵∘{S[⌽p]←S[p←⍵,j←256|j+S[⍵]+⍺[⍵|⍨≢⍺]]}¨S←⍳256⊣j←0} PRGA←{(S i j)(S[256|+/S[j i]←S[i,j←256|j+S[i←256|i+1⊣S i j←⍵]]])} Try it online: https://tio.run/#%23SyzI0U2pTMzJT///qG@qp/@jtgkG/72DHYF0dfCjrsWPerc@6phRHRz9qGdvQSxQNDi6AEgChXWygLSRqVlNljZQtndrrPaj3l0gRs2j3hWPOhcBebGxtYdWBIOVbwaqBBoH0mNQyxUQ5A62QSNYIVMhS1MjOBpkkLZ@cHSWQibElkwU8zOh7ExtQ6ApYF0QV8TGxmrW/v9fXFKUmpgLFAI6XQHokVDnYAV1v8SUzFwF7/yk1Mzi4sxHDf3qXBB1XBrFmXnZYKu9gXpArlGAyCgYKBhwAcUVvPGoAYpRVw0A

Tweeted by dyalogapl on November 9, 2017 at 4:06 PM in reply to noidd

Maltysen

@Adám unless i'm mistaken

setting takes 6 bytes

and u save 2 on eeach use

and their are 4 uses

Adám

@Maltysen Ah a shared var. Hm.

Maltysen

@Adám even better

would be to set it to 255

and on the last 255

use x++

(i'm not sure about the precedence, so tha tmight not work, maybe haveot do ++x on the first 256)

Erik the Outgolfer

apl doesn't have ++ :p

Maltysen

@EriktheOutgolfer lol i was talking about the js one

tho i guess Adam is more concerened about his apl one

true

Mr. Xcoder

5:37 PM

oh hi @SimplyBeautifulArt

Simply Beautiful Art

@Mr.Xcoder heyo

Marcus Andrews

any quicker way to do this?

gets;$<.map{|l|p l.to_i.to_s(2).size}

read in useless int, read and print the number of bits line by line

Simply Beautiful Art

5:53 PM

Language?

Marcus Andrews

ruby

(by quicker i mean shorter)

that one is 37 bytes

Simply Beautiful Art

I feel like gets can be shortened.

Marcus Andrews

I couldn't find a way to

I think that part is bare minimum, just reading/ignoring the first line

J. Sallé

@Adám just to clarify, this calls KSA∘PRGA⊢input?

Marcus Andrews

got it to gets;$<.map{|l|p "%b"%l=~/$/}

Simply Beautiful Art

6:06 PM

Why l.to_i.to_s(2)?

Feel like you should be able to .to_s right away

Pavel

@Adám It's the IDE language bar.

Marcus Andrews

the inputs are strings

errr

i can't recall, for some reason it didn't work (I did try it)

Fatalize

6:45 PM

that stupid red dot in the review queue always makes me think that someone sent me a comment/chat message

eaglgenes101

I want to try doing the tree(3) golfing challenge via depth first search

Thereby outputting tree three via its definition

At least theoretically

Marcus Andrews

My syntax is wrong, how to correct this?

x=gets.to_i
gets.to_i.times{f,t,c=gets.split(" ");if (f.to_i<=x<=t.to_i)p c}

DJMcMayhem

@Fatalize Agreed, I think it's a horrible design choice. Because either you're on a site like PPCG where it never shows up, or you're on SO and it's there 24/7, cause their queues are literally never empty

Pavel

Does anyone know how to modify a java method at runtime with reflection

eaglgenes101

Use case?

Pavel

6:51 PM

@eaglgenes101 I need to make a test with an error pass and I'm not allowed to modify the test source code, so it has to be done at runtime.

Marcus Andrews

Is it not possible to put an if-statement inline with the {} notation?

Fatalize

@DJMcMayhem Yeah it tricked me when I went on SO

Pavel

Alternatively I could just write code that doesn't work to make the test pass, but that seems suboptimal.

@MarcusAndrews Sure it is

Marcus Andrews

How do I correct the code above?

I also tried f.to_i<=x<=t.to_i?p c

Pavel

@MarcusAndrews Try it online!

Marcus Andrews

6:57 PM

ahhh

although now it isn't liking my chained if

maybe that's just a python thing

Pavel

@MarcusAndrews {f,t,c=gets.split(" ");if f.to_i<=x<=t.to_i;p c;end}

Marcus Andrews

hm it isnt' liking that either

Mr. Xcoder

@Fatalize Oh yeah that red bubble that makes me think I'll lose review privileges unless I actually review...

Marcus Andrews

"undefined method `<=' for true"

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Deep Summing code-golf array-manipulation Given an n-dimensional array (or your language's equivalent) filled with numbers, output which p-dimensional row has the largest sum. Input An n-dimensional array, filled with assorted numbers. n, the number of dimensions in the array. (doesn't nee...

Pavel

6:59 PM

@MarcusAndrews Order of operations, try t?1:0 instead of t.to_i. If that doesn't work, (t?1:0)

eaglgenes101

is it theoretically possible to calculare tree(3) directly via depth first search?

Right now I'm trying to adapt loader's number to the tree(3) challenge, though calculating tree(3) via depth first search might be easier

Adám

7:46 PM

@J.Sallé No, it doesn't call anything, it is just two lines which define the two functions, just like the original tweet did.

@Pavel Yeah, I know, those texts are really bad. Total overhaul in progress in time for version 17.0. The new texts will be used across IDE, RIDE, and TryAPL, and I also plan on publishing them as a quick-guide.

Pavel

@AdmBorkBork Do scripts that can take advantage of the PowerShell pipeline have to be written in PowerShell, or could I possibly use another .NET language such as C#? Without using [namespace]::function(), that is.

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