The Nineteenth Byte

Destructible Lemon

12:41 AM

cmc: prove whether or not a variant of brainflak which is vanilla brainflak but {} peeks instead of popping is TC

Zacharý

@ConorO'Brien wut. wut is this.

If there's a round-about way to pop the top of the stack, then it's turing complete.

Destructible Lemon

can't pop at all

{} is the only way to pop in vanilla brainflak

you'd have three counters, but {...} uses the tos to determine looping... which is probably ok considering that 3 cell bf needs one of its counters to be 0 to determine looping

Zacharý

I'd just assume it's not TC... but idk

Destructible Lemon

you've also got to consider that 3 cell bf doesn't have the advantage of the third stack to make manipulating values easier

Zacharý

But it's BF... don't overestimate anything else

Don't underestimate any PPCGer: QFT is a thing.

Conor O'Brien

1:01 AM

@DestructibleLemon can you simulate multiplication by 0 and addition? if so then you can simulate popping

Destructible Lemon

@ConorO'Brien you can't get anything from under the highest value though

there's no way to get anything from a stack but the height and the latest pushed value

so you have 2 counters which can store any integer, 2 counters which can only be incremented, and get incremented anytime you want to store in it's respective store counter, which can be combined to be one counter, by using the difference between stack height

basically the stack is a value, and how many times a value has been put into the stack, rather than actually a stack

on a related note, i'm planning on implementing a quarterstaff2bf compiler in brainflak

Zacharý

1:16 AM

What are the ops of BrainFlak?

Destructible Lemon

esolangs.org/wiki/Brain-Flak

H.PWiz

@ConorO'Brien addition (of the elements at the top of the two stacks) is easy: ({}<>{}) as is multiplication by zero: ({}[{}])

Adám

@H.PWiz Don't stay up too late ;-)

Zacharý

@Adám ...

H.PWiz

@Adám who needs sleep

Zacharý

1:21 AM

What TZ is @H.PWiz in?

H.PWiz

GMT

Zacharý

... rip ..

user202729

1:35 AM

@NewMainPosts Why is there a VTUD...

@EriktheOutgolfer If you don't try to take advantage of the overlap someone will outgolf you...

Conor O'Brien

@H.PWiz I was talking about DL's restriction to the language

user202729

No pop. So push is replace (...) and increase depth, () is one, <> is change stack, <...> is ignore, [...] is negative, [] is depth, {...} is while loop.

Is division/remainder possible?...

Destructible Lemon

not simply, i don't think

i think the third stack will be a considerable asset

user202729

1:51 AM

While loop value = sum of ToS, right?

user202729

2:01 AM

@user202729 Yes.

user202729

2:25 AM

No, it's "sum of all runs".

DJMcMayhem

@H.PWiz ({}[{}]) is subtraction. (<{}>) is multiplication by 0

user202729

So... the code {({}[()])} will evaluate to 0 iff input ==0 or 1, ≠0 for all number>1.

DJMcMayhem

Actually, for all number > 0 it'll be triangle(n-1)

user202729

Anyone write an interpreter for that please?

ASCII-only

@user202729 for what

New Main Posts

2:40 AM

0

Q: How old is it roughly?

Write a short program which takes in a positive number of seconds representing an age, and outputs an estimate of that time in English. Your program must output the least precise amount of time which has past, among the following metrics and their lengths in seconds: second = 1 minute = 60 hour...

DJMcMayhem

@user202729 bit.ly/2GDKG7f

Destructible Lemon

@DJMcMayhem 0/10 could be optimised to not have a stack

0/10 peek defined twice

ok maybe not 0/10 that's mean. i guess you're not going to have a rigourous and high quality interpreter if it's a tio link

DJMcMayhem

@DestructibleLemon Lol

ASCII-only

@DestructibleLemon you could. but if it's written on the spot don't expect it to be production quality

DJMcMayhem

I forgot that {...} uses peek so I added it

Destructible Lemon

2:50 AM

yeah, so i think that the third stack probably makes it TC, because you can hold on to multiple values with it, even if they aren't held as well as on the "stack"

DJMcMayhem

Well, you can't hold a dynamic amount of values on the third stack (afaik)

Destructible Lemon

I think quines would be cooler if they were defined as "a non-empty program which outputs a quine in the same language"

ASCII-only

@DestructibleLemon that would be a metaquine

Destructible Lemon

because the definition has cool recursion and also because it means you don't have to edit the quine to match its output

ASCII-only

or something like that

Destructible Lemon

2:53 AM

@ASCII-only not quite

because a metaquine doesn't refer to itself

and this definition of quine means you can output a program which outputs a program which outputs a program which outputs itself, which a metaquine does not

user202729

tio.run/##vVZLj9owEL7nV1hcsEsWLW1PCPbYW1eV2pubRl5iwN3gRI7ZghC/…

What's wrong with this

Destructible Lemon

my imagined definition a quine (outputs a program which)*outputs itself, except you could have infinite (outputs a program which)

ASCII-only

actually

you're basically saying "a program that outputs another program in the same language"...

Destructible Lemon

not quite

because the program has to be a quine

otherwise you're just outputting a program

ASCII-only

yes.

so it's just a normal quine, except it has to be cyclic

Destructible Lemon

2:57 AM

quine being my imagined definition. no it doesn't have to be cyclic

ASCII-only

i.e. one of the programs eventually has to output one of the other ones

Destructible Lemon

ok so why don't we call my imagined definition something other than quine

ASCII-only

otherwise there will eventually be a program that's not a quine

Destructible Lemon

@ASCII-only not if it infinitely grows

DJMcMayhem

@user202729 I don't think it supports comments

ASCII-only

2:58 AM

@DestructibleLemon that's a good point. but basically it has to be some kind of infinite sequence

Destructible Lemon

it has to be an infinite sequence, or be part of a loop, or lead into a loop

ASCII-only

yep

hmm so it's basically some kind of superset of quines

Destructible Lemon

yes

user202729

@DJMcMayhem But I filtered them out...

source = ''.join([x for x in sys.stdin.read() if x in '()[]{}<>'])

Destructible Lemon

also why are you calling the parts atoms? by definition an atom can't be subdivided. or something

Zacharý

3:03 AM

0/10, not golfed. :p

Atoms contain lexemes, no?

user202729

@DestructibleLemon ...

Probably because it sounds good.

Destructible Lemon

haha true

Zacharý

What's the status on WW's nickname intervention?

DJMcMayhem

@user202729 oh sorry

Destructible Lemon

@user202729 return program_state.toggle() returns None, which then is invalid to add to an integer

(in the code for <>)

you could either change it to call the function, then return 0, or change the toggle function to return 0

(in case i haven't made it clear, it's an interpreter bug)

Downgoat

5:19 AM

question: is there a better way to do: self.parent?.to_json() than a ternary in python

ASCII-only

no

DJMcMayhem

@Downgoat is that even valid? What's with the question mark?

Downgoat

@DJMcMayhem it's not valid, but it's like C# optional chaining

like if self.parent is not null: self.parent.to_json() else self.parent

DJMcMayhem

Ok. Syntactically, you'd want: self.parent.to_json() if self.parent is not None else self.parent

Downgoat

turns out self.parent and self.parent.to_json() works

DJMcMayhem

5:33 AM

Or that

Destructible Lemon

not if self.parent can ever be falsy but not None

@Downgoat yeah but that doesn't look very nice at all

like if i saw that i'd be pretty confused tbh

Downgoat

@DestructibleLemon yeah but the ternary is worse

Destructible Lemon

ternary is clear though

Downgoat

it's pretty common idiom in langs w/o null coalescing

Destructible Lemon

ternary is obvious what it does, the short circuiting you have to realise they're doing short circuiting

ASCII-only

5:34 AM

@Downgoat what is

Destructible Lemon

@Downgoat doesn't seem very pythonic

ASCII-only

@DestructibleLemon short circuiting?

@Downgoat fun fact: i do this all the time

well, too often at least

Destructible Lemon

@ASCII-only short circuiting = abusing and and or operators not evaluating some of their arguments

or evaluating to non-boolean values

ASCII-only

@DestructibleLemon but who doesn't do that

Downgoat

@DestructibleLemon ._________.

Destructible Lemon

5:37 AM

i mean, yes, but it's like, you go "huh why do they need to check whether both these things are true.. oooooh they're short circuiting"

Downgoat

if short-circut is non-pythonic then I don't want my code to be pythonic

Destructible Lemon

whereas the ternary "ok so it's null or it's converted to json"

ASCII-only

@Downgoat ok why are you even using python

Downgoat

@ASCII-only blame-ppcgv2

ASCII-only

@DestructibleLemon well normal people use it a lot?

because python is a scripting language?

Destructible Lemon

5:38 AM

None if self.parent is None else self.parent.to_json() would probably be the best ternary

ASCII-only

@Downgoat :| use C#

Destructible Lemon

@ASCII-only still not exactly pythonic

Downgoat

@ASCII-only 10/10 C# is good language

has sane syntax

ASCII-only

this is why PPCG's Broccoli uses C#

Destructible Lemon

and ostensibly looks like a boolean operator but it's not being used for booleans

Downgoat

5:39 AM

ASCII-only

because it basically is a boolean operator?

Downgoat

testing comments 101 :P

ASCII-only

:O

Destructible Lemon

@ASCII-only but it's not outputting a boolean, is it

ASCII-only

what is this black magic

@DestructibleLemon yes? because it's intentionally overloaded in scripting languages?

Destructible Lemon

5:39 AM

yes, but if you have a clearer way to do something, you should

Downgoat

@ASCII-only btw I'm not sure if we want to use the same UI libraries for mobile and web for VSL

Destructible Lemon

unless it's like, about efficiency

Downgoat

I mean we'll have dedicated DOM bindings anyway

ASCII-only

@DestructibleLemon for a lot of people it's super clear

Downgoat

@DestructibleLemon in good code and a good language these things should go together pretty well

ASCII-only

5:40 AM

@Downgoat mobile app and web?

Downgoat

yeah

Destructible Lemon

also it makes it clear that you expect self.parent could be None, rather than somehow being falsy in some other way

ASCII-only

@Downgoat hmm not sure actually

Downgoat

since VSL compiles to native ios/android/web code, we can have über-crossplatform code bases

still working on swift bindings, I might (ab)use clang to automatically generate UIKit plugs

ASCII-only

i'd say ideally we should have the same library for desktop, mobile, web and mobiel web

Destructible Lemon

5:41 AM

@ASCII-only for some people do while false is really clear

Downgoat

swift has this lovely way of declaring the C-calling conv for certain funcs but I might just plug directly into objective c

@ASCII-only so how would it work then though

because with mobile and desktop

we can have things like class AppDelegate and use strict MVC

web is a little different

ASCII-only

right, good point

Downgoat

I'm not sure how we'd design the library in a platform-independent way

ASCII-only

a while back I was thinking of adding some things to VSL so it could be a hacky markup language

Downgoat

:|

when you say markup language you mean like Markdown? O_o

feersum

5:47 AM

No, like PHP!

Downgoat

oh my

oh god no

ASCII-only

no like HTML just less bad

it would probably be more bad though

Downgoat

actually this brings me to idea

rather than have HTML/CSS/JS seperation

for VSL-based apps on webserver

we could have the frontend coded with the backend (i.e. same codebase)

ASCII-only

example?

Downgoat

and VSL would use lazy classes etc. and we'd basically convert those VSL classes to HTML/CSS/JS

on the fly

so like:

server.route "/animal/goat" to: GoatViewController

class GoatViewController: ViewController {
    init() {
        self.backgroundColor = .black
    }
}

something like that

ASCII-only

5:51 AM

but what if we want pre-generated

also, the bad idea i had:

Downgoat

pre-generated?

ASCII-only

import UI

doc = Container {
	align .Row
	elements {
		Container {
			text "asdf"
		}
		Container {
			text "foobar"
		}
	}
}

Downgoat

you could do something like:

ASCII-only

@Downgoat like something that corresponds 1:1 with HTML/CSS/JS

Downgoat

doc = Container(
    align: .row,
    elements: [
        Container("asdf"),
        Container("foobar")
    ]
)

@ASCII-only You could do that too and just serve those files

but the above seems like cool option

would finally offer alternative to slow crappy electron apps

and then you'd get fast, native app, equaling C++ in speed

ASCII-only

5:54 AM

@Downgoat actually this doesn't look too bad as markup language

Destructible Lemon

2

A: Sandbox for Proposed Challenges

Compile Quarterstaff to BF The title is rather descriptive, except that it doesn't describe what Quarterstaff and BF are. For this challenge, i have created two languages: Quarterstaff, and a dialect of BF that probably already existed in it's exact form, but i wanted to be certain, especially w...

is this ready to post?

oh right, test cases

do i need test cases?

yeah i do

New Meta Posts

6:26 AM

0

Q: Definition of a Function in Concatenative Languages

Concatenative languages are languages where juxtaposition of functions represents composition. Programs consist of the primitives in the language combining to form a large function which takes program input as its argument and whose return value is written to output. In many concatenative langua...

discussion policy scoring languages

Downgoat

thoughts on new ppcgv2 homepage layout

Adám

7:27 AM

@Downgoat Why no stars on left of "Birds" and right of "Golf"?

feersum

Probably black holes

ASCII-only

I think it's a Dyson swarm

Destructible Lemon

8:33 AM

@Downgoat seems like there's a bit of a clash between "birds of etc." and the stars on the background

Fatalize

9:27 AM

So is @ais523 back again?

Erik the Outgolfer

@user202729 I'm not afraid of being outgolfed :P but a good challenge going unanswered at large is kind of a sad sight

ASCII-only

I need a .NET regex matching nested block comments (#| foo |#, #| foo #| bar |# |# etc.) but when I try it turns into an abomination :/

Erik the Outgolfer

@Fatalize 4 recent answers...

Cows quack

@ASCII-only is it for broccoli?

ASCII-only

9:45 AM

yeah

Cows quack

how far is your regex?

ASCII-only

it mostly works

just some things i have to fix

the problem is it looks like gibberish

this looks like it works

Stewie Griffin

10:01 AM

@Scrooble codegolf.meta.stackexchange.com/a/11712/31516

Came to think of it after seeing your deleted answer. It's entirely your choice what to do.

Cows quack

is there any particular reason you have #[^#|] (the # inside the character set)?

H.PWiz

10:15 AM

@ConorO'Brien So was I

@DJMcMayhem I was talking as if {} was peek and not pop.

Destructible Lemon

could i get feedback on my sandboxed challenge before i post it?

4 hours ago, by Destructible Lemon

2

A: Sandbox for Proposed Challenges

Compile Quarterstaff to BF The title is rather descriptive, except that it doesn't describe what Quarterstaff and BF are. For this challenge, i have created two languages: Quarterstaff, and a dialect of BF that probably already existed in it's exact form, but i wanted to be certain, especially w...

ASCII-only

@Cowsquack so it matches the ##| in #|##|

Erik the Outgolfer

how would it match it if you explicitly tell it not to

Cows quack

10:37 AM

@ASCII-only unfortunately it borks on #| #| hi |# bye #| #| no |# no |# h |#

Destructible Lemon

please somebody tell me if it is ready to post

i need feedback

user202729

@DJMcMayhem @DestructibleLemon (I figured it out myself)

Anyway... I have written a code to calculate divide/remainder by 2.

Destructible Lemon

?

user202729

@DestructibleLemon Brainflak peek.

Destructible Lemon

oh ok

call it brainpeek?

user202729

10:43 AM

So with that, it's possible to random access each bit.

@DestructibleLemon Yes, already.

ASCII-only

@Cowsquack yeah :/

Destructible Lemon

ok so i would like feedback on the challenge please

user202729

And thus it's TC. (non rigorous proof)

Destructible Lemon

yeah non-rigorous is not what i wanted

don't make me ping a random person to review my challenge

Erik the Outgolfer

pinging random people isn't productive, it's just noise

Destructible Lemon

10:47 AM

don't make me do it then

user202729

11:51 AM

@DestructibleLemon Should I check for bugs in the interpreter?

Also I think you should specify that BF + and - wraparound.

And... where are the interpreters?

Suggestion: a test case where numbers overflow. (past 256 or negative)

@NewMetaPosts We can never have rule for every language... basically, when in doubt, write a full program.

caird coinheringaahing

12:55 PM

What's the difference between Meta Mortarboard and Main Mortarboard?

user202729

1:27 PM

@cairdcoinheringaahing No idea.

user202729

1:42 PM

I guess 20 upvotes in a day.

DJMcMayhem

2:22 PM

@cairdcoinheringaahing Meta tracks rep the same way as main, there's just no way to access it.

user202729

Does meta have question ban?

DJMcMayhem

2:42 PM

@user202729 I think so.

user56656

lets find out!

caird coinheringaahing

waits for the mass of oneboxes :P

user202729

Feb 7 at 17:04, by Mr. Xcoder

Let's test!

@cairdcoinheringaahing If it's bad enough it will be deleted before NMetaP posts the onebox.

caird coinheringaahing

Could a mod unfreeze this room please?

user202729

It's just a test room...

caird coinheringaahing

2:49 PM

I know, I made it

DJMcMayhem

@cairdcoinheringaahing status-completed

@user56656 I'm pretty sure there is. I can see whether any given user is question blocked or not, and that is visible on meta as well

user202729

CMC: This. (last time I made a stupid mistake, so I'd like to see if anyone does the same)

user202729

3:24 PM

Do'h! I put a bounty on the wrong question, this was meant to be on the cops' challenge. So somebody will get a random bounty. — Nathaniel 8 hours ago

Some mods refund bounty please?

Erik the Outgolfer

nindja'd...

DJMcMayhem

@user202729 status-completed

user202729

@EriktheOutgolfer You're not a mod anyway...

Erik the Outgolfer

I tried to visit that page but dj had already refunded the bounty

...15 seconds before I did

no I don't think I'll ever be a mod, I try to do more real life than PPCG :P

user202729

Why is it still on featured page? SE caching?

DJMcMayhem

3:29 PM

@EriktheOutgolfer That's a wise idea, I probably made a crucial mistake somewhere

caird coinheringaahing

@user202729 It's not, the bounty was moved to the cops challenge

user202729

@cairdcoinheringaahing The bounty on the cops challenge was already...

Erik the Outgolfer

bounties can't "move", but Nathaniel also started a bounty there too when he realized his mistake

user202729

Problem solved for me.

Erik the Outgolfer

@DJMcMayhem here?

user202729

3:34 PM

BTW...

It's safe now . — user202729 9 mins ago

Erik the Outgolfer

I don't know if it's safe before being marked as such, so a more appropriate phrasing would be "you can mark it as safe now"

user202729

Can any close-voters explain? Re @FryAmTheEggman : Is that OK now? I have added the explanation for every symbols appearing in the expression. — user202729 Mar 12 at 11:43

caird coinheringaahing

3:53 PM

CMP

ಠ_ಠ Just realised I forgot JS

user202729

(what is a production language?)

caird coinheringaahing

Something that isn't esoteric/golfing

Something which deserves its own tag on SO for instance

Dennis

@cairdcoinheringaahing Try again. stackoverflow.com/tags/brainfuck

caird coinheringaahing

facedesk Should've seen something like that coming

user202729

4:10 PM

(FYI someone proposed a tag for Jelly recently)

caird coinheringaahing

On SO? Yeah, I saw. The Meta post got really heavily downvoted IIRC :P

DJMcMayhem

4:41 PM

@cairdcoinheringaahing For me it's tied between C(++) and Python

mınxomaτ

@cairdcoinheringaahing C#

Anonymous

@cairdcoinheringaahing Python, PHP, JS

New Main Posts

0

Q: Tic Tac Toe: How to prove that there are 26,830 games possibilities

There are 138 terminal positions after assuming symmetries. 91 (X) 44 (O) 3 (tie) But how to get the 26,830 possibilities, from where I can extract and print this number? The code I'm using created by @Chas Brown Original question: Here import re from collections import Counter FLIP_XFRM ...

python tic-tac-toe

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Build a golfing language with me Tags: interpreter answer-chaining multiple-holes (maybe) Our community has found it necessary to create a set of languages designed specifically for golfing, "golfing languages" as we call them. Such languages have evolved from the once brilliant, now clunky Gol...

caird coinheringaahing

4:56 PM

@Mego I thought you hated JS? and PHP IIRC?

Anonymous

@cairdcoinheringaahing I do. However, a nice person writes their name on my paychecks in exchange for me working with PHP and JS.

Neil

5:15 PM

@user202729 ES6: a=>Math.min(a.length>>1,a.filter(e=>e%2).length)

Mr. Xcoder

@Neil Please use backticks (`) to format your code. (`like so`)

Neil

sorry, oversight

caird coinheringaahing

@Mr.Xcoder May I ask, why do you think the winner should be the one who breaks the chain?

Mr. Xcoder

I feel like it's more appropriate to hand out +15 to someone that came up with an unbeatable (within 2 weeks) strategy rather than to someone that just didn't break the chain.

caird coinheringaahing

Hmm, actually, I see your point. If its about creating a golfing lang, the winner should be the one who is the golfiest

Mr. Xcoder

5:23 PM

Anyway, I don't see how things like: Answer X is ABCD. This adds E, a shorthand for CD: Yay, my answer is now ABE and the chain goes on!... Though the idea is good

Thoughts?

caird coinheringaahing

Preventing the creation of trivial 'shorthands' would be quite difficult. On the other hand, I don't want it to get to 20 answers in, each going "I added a ... builtin, my score is now 1 for this challenge".

One solution I can see, but don't really like (and it has its own flaws), is having a hidden set of 20 questions instead, where only I know the questions and try and craft solutions for each new submission

Mr. Xcoder

Unfortunately preventing things like this might require the use of slightly subjective common sense, which we unfortunately can't use when writing challenges on PPCG

caird coinheringaahing

That's actually something I dislike about writing challenges. Sometimes the best response to "What about if I do this?" or "Why doesn't this break a rule?" is to use some common sense, but we can't say that in the actual specification.

Banning builtins is actually fairly easy: Use a bit of common sense. What is specifically designed for this challenge? It's banned. Does it have general applications? It's fine

Mr. Xcoder

That's ultimately still subjective, but better.

Anyway, how about the multi-part issue?

I literally have 3 challenges ready to post (I don't want to sandbox any of them) and I can't tap the "Post" button because I'm afraid they won't be well received. I didn't feel this when I started writing challenges on PPCG

caird coinheringaahing

@Mr.Xcoder Yeah, that's one of the things I was concerned about when thinking up the challenge

@Mr.Xcoder That's why I leave challenges in the Sandbox for months

Mr. Xcoder

5:32 PM

You know what, well received or not I'm going to post one of them soon

caird coinheringaahing

It wouldn't really be much of a challenge if it was just golfing the solution to one answer. Making it multi-part is the only way it can really work as a proper answer-chaining

totallyhuman

CMP: one question for one piece of code as a language-quiz?

DJMcMayhem

@cairdcoinheringaahing That's what I like about anarchy golf. The rules are "Does it work?"

Mr. Xcoder

@DJMcMayhem Mind if I ask what name you use on Anagol, if you actually golf there?

DJMcMayhem

@Mr.Xcoder Same as here, but I only have like 3 answers

Mr. Xcoder

5:41 PM

Oh ok

caird coinheringaahing

Going through this, answer-chainings are an interesting corner case. The duplicate point already doesn't apply, as the multitask part isn't the premise of the challenge, so identifying a duplicate doesn't rely on the challenges used. There's no point copying other answers, as you're aiming to golf them. Finally, they already have been posted as separate challenges.

That point seems as though it only applies when you can break up the whole challenge into the subtasks, which can't be done as far as I can see.

Mr. Xcoder

CMC: Print 9223372036854775807

New Main Posts

0

Q: Make a BCDto7SEG chip

Source Given a decimal digit in BCD format in cell a[0][3] to a[0][0] (so 8 will be represented as an 1 in a[0][3], and 2 be one in a[0][1]), you are required to output its 7-seg expression in a[10][0] to a[10][6]. Converting Table: a[0][3] a[0][1] a[10][6] a[10][4] a[10][2] a[10][0] ...