The Nineteenth Byte

I recall there being some timezone standard that was basically "whatever is happening in chat", so if someone shows up and says good morning, the timezone is now morning. Does anyone remember where that was posted?

pxeger

this morning

Anush

@hyper-neutrino :)

oh look it’s Tuesday

pxeger

8:24 PM

lol

if you run fast enough, you might get the earth to speed up so that it actually becomes tuesday!

Redwolf Programmed

Gotta love outgolfing perl in JS by almost 60 bytes

For a string related challenge, no less

pxeger

link?

Redwolf Programmed

Not posted quite yet, looking for any more small golfs

Ooh just found a really cool golf

Replacing the normal [...g].filter(x=>x==n).length to count how many times n appears in the string g with g.split(n).length, which is good on its own, but usually you'd need a -1, which I can actually get rid of since I'm modding this by 2

pxeger

you still have to invert it though, but I'm guessing in your case you can just invert something else somewhere else

Redwolf Programmed

Yeah

That saved 14 bytes

Now I'm 69 bytes ahead of perl, so I must stop golfing immediately

pxeger

8:35 PM

fun colour game: kolor.moro.es

Redwolf Programmed

Frick I found another golf :(

pxeger

what challenge is it? I'm on the edge of my seat here lol

Redwolf Programmed

0

A: Brainf*** to tinyBF converter

JavaScript (ES6), 145 bytes b=>[...b].map(x=>p+=[A="=+","+",B="=>",">",C="=|","|",D="==",C+C,"+",A,">",B,"|",C,D,"|=|"]["+-><[].,".indexOf(x)+p.split`=`.length%2*8],p="")&&p Uses an array of the 16 possibilities (8 characters times 2 parities), and indexes into this (that saves three bytes over ...

Mayube

@hyper-neutrino Given I almost always log on and say "good morning" right after Lyxal goes to bed....

user

@pxeger I started out thinking "bah, this is so easy" and by the end I was crying

pxeger

8:41 PM

yeah lol

hyper-neutrino

@pxeger 463 first try

i am suffering

pxeger

I feel like the difficulty curve is a little too steep

hyper-neutrino

it went from "lol this is ez" to "aaaaaaaaaAAAAAAA"

pxeger

I got 572

Redwolf Programmed

Ooh just found a big byte save

Now 88 bytes head of perl :p

pxeger

8:46 PM

tbf, that perl answer looks far too readable to be competitive

I'm sure an experienced perl hacker could do much better

Redwolf Programmed

Yeah, I mean it is like 5 or 6 years old so golfing wasn't as good as it is today

(Although that might just be for JS, I think perl golfing was more common back in the dark ages)

Unrelated String

yeah perl golf is an ancient tradition

user

@RedwolfProgrammed Yes, back in the old days, they even used shudders variables with multiple characters in their names

caird coinheringaahing

This site was founded on perl golf :P

user

I try to forget code golf's roots /s

caird coinheringaahing

8:51 PM

Well, I wrote up the history of the site, so ¯\_(ツ)_/¯ :P

Redwolf Programmed

I'd guess that JS is probably the language that's had its golfiness evolve the most over time. Looking at early JS answers vs. modern ones, the difference is crazy.

Anush

ah perl...do people still use it?

it was huge in bioinformatics at one point

caird coinheringaahing

Seems like there's not really any objection to this, anyone mind if we go ahead and do it and mark it status-complete?

user

Yes, it's quite commonly used, although for different stuff from JS, probably

caird coinheringaahing

@Anush On this site, from time to time

Redwolf Programmed

8:53 PM

@RedwolfProgrammed Most of that is the language itself evolving, which makes lots of other things shorter and makes techniques like recursion possible, but I think JS golfing has gotten a lot more advanced since then (e.g. look at an answer by a top JS golfer)

pxeger

@Anush I don't think much production code uses it, but it's still a popular language for ad-hoc scripting

Anush

where is perl most used IRL these days?

user

@cairdcoinheringaahing @pxeger Want to write your opinion here or are you okay with it now?

@Anush It's good at string stuff

pxeger

@user nah it's ok I've seen the light

Anush

@pxeger interesting

caird coinheringaahing

8:54 PM

@RedwolfProgrammed Yeah, compare Arnauld's answers to old JS answers, even translating the old answer to updated JS, and it's crazy how much golfier he is

Anush

@user yes. I always used it as a better awk

that's how I think of perl. awk++

Awkward

lol

:)

Would sed++ be sedimentary?

Sedition? Seduction?

Anush

8:55 PM

it might even have been invented as a better awk

it's also very fast for some strings things. Much faster than python for example

the problem is python is crazy

has anyone taken this test?

a=257

b=257

a is b

what is the output?

caird coinheringaahing

> True

Try it online!

Anush

@cairdcoinheringaahing incorrect

do it without the print

it is False

pxeger

@Anush implementation-defined, depending on github.com/python/cpython/blob/… - which is why it's different on TIO @cairdcoinheringaahing

caird coinheringaahing

Then it doesn't output anything

Anush

if you do it in ipython or jupyter notebook you will get False

now do the same thing with

a=1

b=1

a is b

answer?

pxeger

8:59 PM

True

caird coinheringaahing

Isn't this because Python typically caches the integers from 1 to 256?

Anush

now try a=257;b=257;a is b

Redwolf Programmed

@cairdcoinheringaahing I've always wondered what that really means...how do you cache a literal?

pxeger

@cairdcoinheringaahing to be specific, CPython caches -5 to 256 inclusive

Anush

@pxeger yep

caird coinheringaahing

9:00 PM

@RedwolfProgrammed Caches the memory addresses I believe, rather than writing them to memory when first used, then reading them

Redwolf Programmed

I still don't really get it

pxeger

it caches the integer object. In Java-speak, all Python integers are boxed (because they're bigints), so they need to be heap-allocated

caird coinheringaahing

@RedwolfProgrammed It's like 90% of CS: pretend you understand the explanation someone gives you, then ignore it and keep coding

Redwolf Programmed

@pxeger Ohhh it has to do with them being bigints, doesn't it?

pxeger

yes

Redwolf Programmed

9:03 PM

That makes sense

Anush

now try this a="hello!";b="hello!";a is b

and a="hello";b="hello";a is b

what do you get?

pxeger

True for both

Redwolf Programmed

for both

Anush

I get False for the first one and True for the second

twitter.com/abelmbula/status/1369550562518310916?s=20

Redwolf Programmed

The fact that Python has UB is actually kinda cursed

Anush

9:04 PM

and so does this person :)

user

@Anush This is why you use ==, it's not that Python is crazy (well, it is, but not here)

Redwolf Programmed

@RedwolfProgrammed I'd have thought we all decided to move past that

user

@RedwolfProgrammed I'm sure most languages have plenty of UB

pxeger

any time you use the same constant in the same code object (where both uses are compiled at the same time - e.g. in the same statement line at the repl), they get deduplicated

Redwolf Programmed

Although I mean my language of choice is JS where everything is UB

pxeger

9:05 PM

@RedwolfProgrammed in fairness, if you type 1 is 1 directly, you'll get a warning

Anush

what's the explanation for "hello" vs "hello!"?

pxeger

@Anush I don't know, because I didn't get those results

Redwolf Programmed

Are you doing it in a REPL one line at a time?

If you do that for one and not the other I could see it changing results

Anush

jupyter notebook

I just discovered github.com/satwikkansal/wtfpython

that's a great site for python fans!

Redwolf Programmed

The walrus ones all seem perfectly reasonable to me

This isn't going to be like all those wtfjs repos where it's just intentional language features without the necessary context for why it's done is it...

user

9:08 PM

Walruses are always reasonable

Anush

:)

user

Walruses > Pythons > Humans

@RedwolfProgrammed They do explain the walrus operator more later

Likewise with the is thing

Redwolf Programmed

The reason the walrus operator does that is perfectly reasonable though. This just feels like someone took their operator precedence bugs and posted them online as if they were python's fault :p

I like bashing stupid language features, especially for Python and JS, but it's more fun when it's fair lol

Unrelated String

^

caird coinheringaahing

I like bashing stupid language features, across all languages except for Jelly, as they annoy me when I have to add bytes to compensate for them :P

caird coinheringaahing

9:52 PM

Could a mod unfreeze the Add++ room please?

(cc @hyper-neutrino)

Anush

10:22 PM

pbs.twimg.com/media/FDefAE5XoAA22Tc?format=jpg&name=large

More for python fans

user

Nothing weird about it

Anush

:)

Fmbalbuena

im almost python fan but add++ is 51% fan and python is 39% fan

user

You're just multiplying by 5 in a weird way

Anush

@user yes!

user

10:24 PM

~~The real weird thing here is that the screenshot was taken on a Mac~~

Anush

:)

I thought it was a cool coding trick

Adám

@Anush APL equivalent: i.imgur.com/AFg9Kvs.png

Anush

Nice!

and I could almost read it :)

Adám

What part is hard to read?

user

What does With do? Just puts the following names inside the items namespace instead of the outer one?

Adám

10:31 PM

It temporarily switches to the items namespace (object), causing all following (until :End) assignments to happen in there. I used it because we haven't implemented the literal namespace notation yet.

Alternative way to do it.

Once the literal notation is implemented, we'll be able to write:

      items←(
       laptop←600∘×
       raspberry←5∘×
       arduino←50∘×
      )
      items.raspberry 5
25

user

I'm kinda surprise the current ways to do it are so verbose (for APL ,at least)

Fmbalbuena

@Adám are you fan of APL?

6

Im bad at APL

Adám

@Fmbalbuena I can't deny that.

@Fmbalbuena We can fix that.

Fmbalbuena

i cant type the codepage of apl

Adám

@user Namespaces have not been seen as a core part of language. Hopefully, that'll begin to change with the literal notation.

Fmbalbuena

10:39 PM

copy paste repeat

Adám

@Fmbalbuena apl.wiki/Typing_glyphs

user

@Adám When do you think it'll be implemented?

Fmbalbuena

ok and i dont learn nothing. i know only one: ⍝

Adám

Hopefully for the next version (19.) after the one that's currently in beta (18.2).

user

@Fmbalbuena You've earned the Comment privilege!

Now you have the ability to say ⍝ TODO write APL :P

Fmbalbuena

10:42 PM

hahaha

Adám

@Fmbalbuena Well, that one is very important :-) Maybe apl.wiki/Mnemonics can help you?

Fmbalbuena

Please separate by comments what does 99 bottles of beer program look like in A Programming language

Adám

Separate by comments?

Fmbalbuena

like This

Adám

OK, but it can be written in a single line.

Fmbalbuena

10:46 PM

and separate by comments

Adám

OK, working on it.

lyxal

@Adám ooh I like that (1=⍵)↓'s of beer' trick

Adám

It is very common.

lyxal

There's just something about that one part that stood out at me and screamed elegance

Of course, that could just be because I've been conditioned to love APL

Adám

@Fmbalbuena tio.run/##lVHLbsIwELzzFSNfkkhwyBFV/AL/…

Fmbalbuena

10:52 PM

but i still cant understand just like malbolge

Adám

Whoa, it can't be that bad. What is it you don't understand?

Fmbalbuena

why theese {}⌽⍵

I can't understand how prints 1 bottle instead of 2 bottles without if statement

Adám

{…} encapsulates functions. Without them, the code inside would attempt at running right away.

⌽ is reverse a list

⍵ is the (right-hand) argument of each function.

@Fmbalbuena It generates the list 99,98,97,…,2,1 and calls the beer function on each, collecting the resulting strings.

Fmbalbuena

@Adàm i still don't understand

but i still need to understand APL programs

Adám

When the argument is 1 the expression 1=⍵ gives 1 so it drops (↓) 1 (the first) character ("s") from the last part of the string.

rak1507

10:58 PM

@Fmbalbuena do you know python slicing? it's like 's of beer'[n==1:]

Adám

@lyxal That's the beauty of

Iverson bracket

In mathematics, the Iverson bracket, named after Kenneth E. Iverson, is a notation that generalises the Kronecker delta, which is the Iverson bracket of the statement x = y. It maps any statement to a function of the free variables in it that takes the value one for the values of the variables for which the statement is true, and takes the value zero otherwise. It is generally denoted by putting the statement inside square brackets: [ P ] = { 1...

Fmbalbuena

try

Adám

@Fmbalbuena I'll be happy to help, but 1) you need to tell me what's troubling you, and 2) maybe we should move to apl.chat so we don't flood this room.

(Also, to include a quote in your string, just double it.)

Fmbalbuena

@Adám Moved

New Posts

11:46 PM

0

Q: A rolling drop gathers all pearls?

Quell is a single-player grid-based puzzle game. Pearls are scattered across a 2D map and the aim is to collect them all by rolling a drop of water over them. For this challenge we will only consider basic maps containing the drop, pearls, walls, and empty spaces. (The full game includes a variet...

Transcript for