The Nineteenth Byte

Conor O'Brien

17:00

@ГригорийПерельман hint: ? followed by a character is a string literal

ETHproductions

@MartinEnder Would that be equivalent to... !":!!":"!"?

Martin Ender

no, it's equivalent to !":" ? !"!" : "!"

ETHproductions

Oh... ? must cause some awfully weird parsing scenarios

Conor O'Brien

not to mention it can be at the end of a function

Григорий Перельман

How does Ruby know when you use ? as ternary and when to use it as a character literal.

Conor O'Brien

17:01

so a.b?3:4 is invalid

@ГригорийПерельман if ? is followed by whitespace, then its a ternary, otherwise, it a char literal

ETHproductions

@ConorO'Brien That's kinda like 123.toFixed() in JS is invalid, I guess

Conor O'Brien

yup

Martin Ender

@ETHproductions yeah, identifiers can end in ? or ! as well and : is also used for symbols

ETHproductions

IMHO languages should have as few multiple-ways-to-parse instances as possible (zero preferably)

Григорий Перельман

So you can do foobar.string? to check if foobar is a string. Functions also don't need parentheses to call them.

I remember now

ETHproductions

17:04

Yeah, I know a little Ruby as well

Jan Dvorak

> Now, this doesn't deserve a WAT. It's just a sign of how awesome Ruby is. Now, if you ever actually do this ... WAT.

Conor O'Brien

xD

ETHproductions

Well I guess the second ? there does come after a character literal, forcing it to be a ternary since the other two options wouldn't be valid

Conor O'Brien

irb(main):017:0> ??.string?
NoMethodError: undefined method `string?' for "?":String

ETHproductions

Um

Cyoce

17:05

??.what?

Jan Dvorak

irb(main):001:0> ??.is_a? String
=> true

ETHproductions

Oh, .string? doesn't exist on anything?

Jan Dvorak

@ETHproductions you could add it

ETHproductions

True

Jan Dvorak

But, if you do... WAT

ETHproductions

17:06

I like that you can change the behavior of operators in Ruby glares at JS

Григорий Перельман

I could have sworn it was a thing tho...

Jan Dvorak

There's a nil?

Григорий Перельман

Yeah

Cyoce

nil is special.

ETHproductions

That wouldn't work in JS, if you try to get a property of null it just throws an error

Григорий Перельман

17:07

for loops are weird in Ruby

Cyoce

Don't use for loops in Ruby

Григорий Перельман

list.each |x| {
    # do stuff
}

Conor O'Brien

@Cyoce yes

Cyoce

@ГригорийПерельман that's wrong... it would be:

TuxCopter

@ГригорийПерельман list.each do |x|; end

Jan Dvorak

17:08

@ГригорийПерельман did you mean each?

ETHproductions

@ConorO'Brien Ooh, just found a good test case for a JS parser I'm attempting to create

Григорий Перельман

Yeah.

Cyoce

list.each { |x|
  # do stuff
}

ETHproductions

^

Григорий Перельман

Gah

Conor O'Brien

17:08

@ETHproductions oo fun!

Григорий Перельман

For loops are stupid.

fəˈnɛtɪk

Ruby likes iterables

Jan Dvorak

I like loop.with_index do |_, i| ... end

TuxCopter

Or there's list.each.each.each.each.each.each.each do |x|; end

Григорий Перельман

It might just be me doing it wrong, but { ... } only seems to work with for-each loops and not any other kind of construct.

Jan Dvorak

17:10

@TuxCopter now, if you ever actually do that... wat

@ГригорийПерельман you can pass a block to any method

Cyoce

@JanDvorak Um... loop?

Conor O'Brien

@ГригорийПерельман it should work with any that requires a block

Григорий Перельман

I can't seem to get it to work with if, it just doesn't want to.

Jan Dvorak

@Cyoce yep. It just calls its passed block forever, or returns an enumerator to do that

Conor O'Brien

@ГригорийПерельман if isn't a function

Cyoce

17:12

@ГригорийПерельман it's called a block. You can pass a block to any method, and your methods can implement it by calling yield to invoke the block, or saving it to a parameter by putting an additional parameter with an &in front of the name

Jan Dvorak

with_index is a method that modifies an enumerator

Григорий Перельман

Is do ... end a kind of "block" literal?

Cyoce

    def thing_with_block
      yield
    end

    def other_thing_with_block(&block)
      block.call
    end

Jan Dvorak

@ГригорийПерельман yep

Григорий Перельман

I see.

Jan Dvorak

17:13

g2g, battery dead

Григорий Перельман

o/

@Cyoce What does yield do?

Jan Dvorak

@ГригорийПерельман it calls the passed block

Cyoce

@ГригорийПерельман it calls the block passed to the method yield is in if you don't want to save the passed block as a parameter

Conor O'Brien

@ETHproductions do you have a github link for this?

Cyoce

The two examples I gave do the same thing.

ETHproductions

17:14

No, I just started writing it in a Notepad++ document last night

Григорий Перельман

And what does &block do? Why isn't is just block? I have so many questions

Conor O'Brien

nice, can't wait :)

ETHproductions

I'm working on the tokenizer ATM. Numeric literals are hard

Cyoce

@ГригорийПерельман the & indicates that it's a block parameter, not a normal one.

Григорий Перельман

So, ruby doesn't care about types, except for blocks and nonblocks.

Conor O'Brien

17:15

@ETHproductions how so?

Cyoce

No. Blocks just have special syntax.

ETHproductions

Actually, now that I think about it, I started this parser thingy as the first step in creating a tool that looks for potential golfs in JS code-golf entries

Григорий Перельман

._.

Ruby is weird.

Jan Dvorak

Blocks aren't a type, it's a syntax construct

Cyoce

If you wanted to, you could just pass a proc as a normal parameter. That's what &blocks get converted to.

Conor O'Brien

17:16

@ETHproductions funny, I was thinking about making a parser of my own to make an auto-JS obfuscator. Not too different, haha

ETHproductions

@ConorO'Brien There's 123 and 123.456, and then there's 0x123 which doesn't ever have a decimal point, etc.

Maybe I'm just overthinking it

Conor O'Brien

yeah

you should just parse all possibly valid number sequences then check them later

Григорий Перельман

Can you do special things like 1.f in JS?

ETHproductions

Oh, and there's numbers with a leading decimal point as well (.123)

@ГригорийПерельман Nope, that throws a SyntaxError. Not sure what you're trying to do there though

1.f throws an error, 0x1.f returns the f property of 0x1

Григорий Перельман

In Java, 1.f specifies that it's a float and not a double.

ETHproductions

17:20

Ah. JS doesn't have anything like that, other than 0b, 0o, and 0x for binary, octal, and hex literals

Григорий Перельман

You can do 1f, 1d, 1l

ETHproductions

JS also only has one generic Number type

Conor O'Brien

number  = "0" + ("x" | "b" | "o") + DIGIT_SEQUENCE
number |= DIGIT_SEQUENCE
number |= DIGIT_SEQUENCE + "." + [DIGIT_SEQUENCE]
number |= "." + DIGIT_SEQUENCE

using some sort of pseudo parser language

ETHproductions

heh, I'm just coding it from scratch in JS

Conor O'Brien

oh, nice

ETHproductions

17:21

I don't know any parsing tools

Григорий Перельман

Java has 0b101 and 0xf42 but also just plain old 042 for octal.

@ETHproductions So is all division float division?

ETHproductions

Right

JS also has 042 octal literals as well

Conor O'Brien

If I were you, I'd have some sort of needle function, where needle("str") returns true if, from the current parsing index, the next characters are s then t then r. If you're not adverse to using regex, you could integrate regex into this needle function. Tho I have no idea how you're rolling this

Dennis

@ETHproductions Which is a bit weird considering it has typed arrays.

ETHproductions

I should probably write a helper function to strip the first match of a regex off of the current code and return it (e.g. code = "1+2", f(/\d+/) == "1", code == "+2")

@ConorO'Brien Just some looping and some regex

TuxCopter

17:24

Hai

Oh wait I already posted

ETHproductions

@Dennis Well, those were added long, long after JS was first designed...

Григорий Перельман

Are you making a JS linter or something?

Conor O'Brien

@ETHproductions I think I have written a function that does that, one sec

ETHproductions

@ГригорийПерельман Yes, exactly. A JS linter whose style is "make the code as short as possible". That's a perfect way to put it

It doesn't make the changes for you, just alerts you where changes could be made

Dennis

@ETHproductions I know. But why not add the numeric types as well?

ETHproductions

17:26

This is true...

Григорий Перельман

If its for golf you probably just don't need to support octal and binary.

Conor O'Brien

it's better to support the general case

ETHproductions

I was going to use the babylon-parsed tree, but a) those are a little too complex for me to work with right now, and b) I wanted to try making my own parser

Stewie Griffin

Shout out if you were already working on this, (or if you think it's a good challenge) and I might undelete it.

Conor O'Brien

// returns [removed, code] if match succeeded, false otherwise
const stripReg = (code) => (regex) => {
    if(code.search(regex) === 0){
        let [mat] = code.match(regex) || [];
        return [mat, code.slice(mat.length)];
    } else {
        return false;
    }
}

let code = "1+2";
let r = stripReg(code);
let p;
[p, code] = r(/\d+/);  // ["1", "+2"]

@ETHproductions found it

ETHproductions

17:30

Oh cool, that might strip out a lot of the ifs I'm using

Stewie Griffin

@ConorO'Brien, wow! You're absolutely terrible at golfing!

Conor O'Brien

@StewieGriffin it's not for golfing >_>

ETHproductions

Oh, it won't strip out the ifs, it just means I can use one regex per token instead of three

Conor O'Brien

@ETHproductions oh quick note this doesn't work

ETHproductions

Um, ok, what doesn't work about it?

Conor O'Brien

17:32

the curried function saves the original string instead of using the modified string

make it non-curried and it should work

ETHproductions

ok, cool

Maybe I'll just declare it inside the loop so it can directly modify the code variable and I'll only need to input the regex

Dennis

@StewieGriffin Why did you delete it in the first place?

betseg

you get a cookie if you can figure out what this does without running it

Conor O'Brien

is this C?

betseg

yes

i wrote it :D

Dennis

17:36

@betseg Runs on TIO, hits cache.

Basic Sunset

@betseg ...it makes my brain hurt

betseg

@Dennis easier to run on tio than compiling and running on my pc

ETHproductions

Whoa... is _ an addition function using only bitwise operators?

Dennis

:D

betseg

@ETHproductions yes, also a ternary operator

ETHproductions

17:38

Well yes, but no arithmetic

Stewie Griffin

@Dennis The immediate downvote, followed by a feeling that there might be more coming...

betseg

@ETHproductions a?b:c; == if(a != 0) { b; } else { c; }

ETHproductions

I am aware of what a ternary operator does :P

Stewie Griffin

I can reopen it though, if you (and/or someone else) think it might be a good challenge...

ETHproductions

I just can't believe I figured out what that small part does without running it

DJMcMayhem

17:40

@StewieGriffin link?

Conor O'Brien

@betseg hm, let me just consult the table of bitwise operators that I've memorized...

Stewie Griffin

12 mins ago, by Stewie Griffin

Shout out if you were already working on this, (or if you think it's a good challenge) and I might undelete it.

Dennis

@StewieGriffin Ultimately your call, but I don't think you should a post because of a single downvote.

Conor O'Brien

IMO it's not a fun challenge to decipher, because it mainly relies on recursion and bitwise operators

ETHproductions

...and __ is multiplication without arithmetic operators, right?

betseg

17:41

@ETHproductions ;_; yep

Have a piece of cookie

ETHproductions

Now I'm stuck at [ 0 ...4], I'm not familiar with whatever that C syntax is

Mistah Figgins

@StewieGriffin For those of us who can't see that deleted post, what was the general idea behind it?

Stewie Griffin

@MistahFiggins Undeleted it. Hopefully someone will enjoy it :)

betseg

@ETHproductions Basically all the elements between 0 and 4 i.e. from _8[0] to _8[4]. It's a GCC extension IIRC, can be rewritten as [0 ... 4]

ETHproductions

Got it. That's what I thought after reading the surrounding code

New Main Posts

17:44

0

Q: Lists and arrays, part by part

In this challenge, you'll get four different but somewhat related tasks that must be solved in a specific manner. First, I'll explain the tasks, then follows an explanation of how you must solve it. Your code should for all four tasks take two positive integers as input: n,m, where n<m. All task...

ETHproductions

I'm learning quite a bit of C today :P

Ah-ha! It prints the chars of {100+4,100+1,100+8,100+8,100+11}, that is, hello

That was fun :)

You should have used _(_8[_0],_7[_0++]) at the end though :P

betseg

Oh I forgot :p

ETHproductions

And _0=_(_0,1<<0)

Conor O'Brien

@betseg ok, I think I got it. I had to think a while on _. Darn bitwise operators. From there it was easy

still so much fun :D

AdmBorkBork

@ETHproductions The language I'm working on is precisely this.

Conor O'Brien

17:50

I don't know C, but I think this is equivalent

@AdmBorkBork hype is it just in design phase, or have you started writing it? is there a github?

AdmBorkBork

Still in design, no github or anything yet.

betseg

@ETHproductions 🍪

ETHproductions

A really good C minifier or optimizer or something might be able to golf that program down

@betseg :D

Conor O'Brien

do I at least get compensation cookie for expanding code? lol

AdmBorkBork

A register and a double-ended stack (i.e., you can "pop" from either the top or the bottom). Operators manipulate the register and the appropriate "top" of the stack, then store the result back in the register.

betseg

17:52

@ETHproductions lemme try with gcc -O3

Conor O'Brien

@AdmBorkBork this sounds like glorified assembly code haha

AdmBorkBork

I also plan on having an operator that is something like "Parse the rest of this line as PowerShell, passing the entire stack as the $args arguments"

ETHproductions

@ConorO'Brien Shoot, how will I parse template literals?

With the nested ${}s and all

betseg

nope even -O3 doesnt optimize the _ function to add

Conor O'Brien

@ETHproductions recursively? e.g., have a parseLiteral function, then for each ${ encountered, just call that function

AdmBorkBork

17:54

@ConorO'Brien The items on the stack aren't individual digits. You could "push" an array and it would be one element on the stack, for example.

Conor O'Brien

oh, that's cool

long live stack-based languages!

L3viathan

Oh damn it. I got the reciprocal almost sorted out, except for the case of zero point something.

betseg

@ConorO'Brien [0...4] gives an error btw, GCC says there are too many decimal points

Conor O'Brien

oh, forgot a space

DJMcMayhem

CMC: Print 'cat' (with any variation of capitals) in 32 or less bytes of brainfuck

@Riker

Conor O'Brien

18:05

Try it online!

Riker

o-o

DJMcMayhem

@ConorO'Brien 🍪

Riker

10/10 thanks

Cyoce

Just barely met the byte requirement...

DJMcMayhem

@Riker Oh wow, I almost didn't recognize you with your new avatar

Riker

18:06

lol

not for too long but I like it atm

betseg

woah that wasnt someone else i though that was someone else

Riker

lol

yeah, I'm not sure imma keep it

mainly because I use avatars to recognize people and I don't want to annoy anybody

Kritixi Lithos

Change the colours to be in this order: red, green \n blue, yellow

then you become windows cat

Riker

no.

windows causes global warming

or at least house warming

Conor O'Brien

but they also allow one to see clearly

Григорий Перельман

18:09

And they leak heat in the winter

New Main Posts

0

Q: Using Recursion to Solve Addition Problems

This is a homework question which I have no idea how to start, hoping for some pointers. Suppose I have a pair of integers represented in the form of ABBAC + BAC = ACCCD, where each alphabet represents an integer from 0 - 9, write a recursive code which computes the number of integer solutions ...

recursion

Riker

already closed

Григорий Перельман

@NewMainPosts ._.

Erik the Outgolfer

@NewMainPosts You had one job...

Григорий Перельман

How do I politely say "SO won't do your homework for you either m8"

Conor O'Brien

18:11

You don't.

betseg

let them learn the hard way?

Conor O'Brien

*sigh* did either of you two even read the be nice meta post

Григорий Перельман

My bounty on codegolf.stackexchange.com/questions/114219/… has finally paid for itself in upvotes, but no one's answering ;-;

@ConorO'Brien Yes, which is why I haven't commented on the question yet.

L3viathan

I guess the question could actually make for a good PPCG question

Riker

Netflix celebrates April Fools Day with a "live" show that is available for only one day. It's literally Will Arnett commenting on whatever is in front of him.

ETHproductions

18:13

@ConorO'Brien But that defeats the purpose of tokenizing...

Conor O'Brien

@ГригорийПерельман relevant

Григорий Перельман

It's still March tho... foo.

Riker

@ГригорийПерельман :P

tbh it is april 1st in some countries atm

ETHproductions

I had to deal with nested strings in Japt. Took me about 50 hours over the course of a year and a half to get it just right

Григорий Перельман

Ik

@ETHproductions Nested strings? You mean backslash escaped or some other way?

Conor O'Brien

18:15

@ETHproductions how so? It's the only sane way to deal with it that I can tell

ETHproductions

@ГригорийПерельман Like template literals in JS: (`a${`b${`c`}d`}e`)

Riker

btw, I did steal that from reddit @ГригорийПерельман

and the top comment is gold

> Did I need to watch Will Arnett narrate a microwaved burrito? No, but it was amazing.

Erik the Outgolfer

@Riker I'm in Greece :(

Григорий Перельман

Should I know who Will Arnett is?

Erik the Outgolfer

And I'm not in the mood to enable VPNs and such.

Riker

18:16

@ГригорийПерельман nah

@EriktheOutgolfer :/

ETHproductions

@ConorO'Brien Yes... I don't think it's possible to tokenize in such a way that allows for nested strings

:'(

Riker

define nested string?

iirc tokenize module supports that

but that's python

ETHproductions

1 min ago, by ETHproductions

@ГригорийПерельман Like template literals in JS: (`a${`b${`c`}d`}e`)

Riker

ah

Григорий Перельман

UUuuuu .NET balancing groups

Conor O'Brien

18:17

in stacked, I don't like the way I do it, but it works. I account for characters in strings, and work with depth, but it's blergh

Kritixi Lithos

@ГригорийПерельман ikr, they are so weird and amazing

ETHproductions

@ConorO'Brien That's what I do in Japt as well. I think that's really the only way

Conor O'Brien

is JS open source?

we could try taking a peek there

ETHproductions

Makes me wonder how template strings were one of the first ES6 features to be implemented, since they break most conventional parsing methods

Григорий Перельман

I don't think it's FOSS

ETHproductions

18:19

@ConorO'Brien I think the V8 engine is, not sure though

Erik the Outgolfer

@ConorO'Brien JS isn't one thing AFAIK, browsers have different variations.

ETHproductions

github.com/v8/v8

Conor O'Brien

right, so any implementation would be ok

@ETHproductions oh, fun, into the rabbit hole.

Григорий Перельман

@ConorO'Brien FireFox is open source, you can check in there.

betseg

> Google Chrome, the open source browser from Google

Григорий Перельман

18:20

I thought chrome was proprietary

betseg

Chrome is closed source, Chromium is OSS

Григорий Перельман

I guess not?

betseg

@ГригорийПерельман ye

Григорий Перельман

Wait confused now

Erik the Outgolfer

Yeah, it's Chromium. Chrome has proprietary stuff in it, so you can't really consider it 100% OSS.

ETHproductions

18:21

This file has several mentions of template literals, not sure if it's useful though

Actually, this looks like a good place to search

Григорий Перельман

What's v8 licensed under?

oic it's BSD

Riker

@flawr en.reddit.com/r/KenM/comments/62l4md/…

@ГригорийПерельман woah, have you seen this? en.reddit.com/r/place

betseg

@Riker can i place only 1 square? i dont want to waste :P

Riker

I can't figure out how to place it >:U

or maybe I accidentally did already

Conor O'Brien

@ETHproductions you know, I don't feel so bad about variable names anymore. DCHECK(next_next_.token == Token::UNINITIALIZED);

ETHproductions

18:29

Oh, really found it this time (I think): github.com/v8/v8/blob/3f8b2aeb3587dad6a279d439db56db785197253a/…

Conor O'Brien

was just about to link that

betseg

@betseg oh every 5 min

Riker

ah

ETHproductions

@ConorO'Brien Why do their variables all have trailing underscores :P

Riker

that explains it, I was wondering how people drew those things

New Main Posts

18:32

-1

Q: Ghost in the shell

In honor to the 1995 classic ghost in the shell (of which I'm going to see the remake tonight) I propose a challenge where you create a shell with a ghost in it. The challenge: Create a REPL shell that evaluates numerical statements and has a chance of returning the wrong numerical answer betwe...

code-golf random repl shell

Conor O'Brien

@ETHproductions I have no idea, it's starting to tick me off lol

heyy we should see how narcissus does it

ETHproductions

narcissus?

Conor O'Brien

it's a javascript self-interpreter

ETHproductions

from a quick search through the source code, it appears that it just doesn't

not yet, anyway

betseg

> Latest commit by dherman about 5 years ago

Probably not gonna happen either

Conor O'Brien

18:41

true

ETHproductions

Well, I guess that means that I'll have to be the first to do it in JS

(jk, I'm sure it's been done before in other linters/minifiers/etc.)

the heck, how did I switch rooms there

Григорий Перельман

@MendeleevLemon I just saw Matthew. I asked him if he installed Gentoo yet, he threw a pencil at me and referred to what happened as "Creepy as fuck" and "How the hell did you know I was there"

2

Kritixi Lithos

~~in real life?~~ well obviously, I suppose

ETHproductions

Do you three live near each other, I guess?

Григорий Перельман

Same county, but it would be completely impractical for me to be able to get to Lemon's house.

Dennis

18:52

Matthew?

Григорий Перельман

Lemon's dad gives Matthew private lessons in Physics

16 hours ago, by MendeleevLemon

@Dennis Just a guy I know, he's not on PPCG.

Conor O'Brien

invite him

Григорий Перельман

I did.

Kritixi Lithos

@ГригорийПерельман oh, I thought you meant SIGSEGV

Basic Sunset

I didn't even realize that's who SIGSEGV was

ETHproductions

18:54

@KritixiLithos heh, I did too

Dennis

MatthewOverflow

user165474

@ГригорийПерельман Which lemon?

Erik the Outgolfer

@ГригорийПерельман Pavel is sooo evil. How could a mortal install that mess?

ETHproductions

@HyperNeutrino the Mendeleev one

user165474

Okay. Thanks.

user165474

18:56

Oh wait maybe I should have checked who wrote the original message ;_;

user165474

Also is SIGSEGV (not the user) a segmentation-fault or is it something else?

MendeleevLemon

@ГригорийПерельман :D

Григорий Перельман

@HyperNeutrino Signal: Segmentation Violation

user165474

Oh okay, thanks.

user165474

So when is the signal raised? I think it's when something tries to access a forbidden section of memory but I'm not sure.

MendeleevLemon

18:59

Is Place the Reddit april fools thing?

I was hoping for a reprise of Robin

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