The Nineteenth Byte

Nathan Merrill

4:00 AM

I think that (i int) is rather bad syntax, as it looks like a parameter

quartata

The implicit return that is.

Nathan Merrill

what? the return is explicit in the example

Pavel

Why does the return value need a name?

quartata

The point of it is that if you have that then all you do is return and it returns i

Nathan Merrill

@Pavel so you can reference it in your deferred function

quartata

4:01 AM

@NathanMerill It's reusing the syntax which puts it on my warpath

Sherlock9

Lisp questions for you guys: Do you know of a good introduction to Lisp? Should I just read John McCarthy's paper and work from there?

Pavel

uhhhhhhhhh it probably would have helped to know the rest of this conversation.

Nathan Merrill

@quartata oh, so you override the return?

quartata

@Sherlock9 Try Racket it has good tutorials and a better stdlib than other Scheme flavors

Nathan Merrill

so, a better syntax would be defer func() { return i + 1}?

Qwerp-Derp

4:02 AM

@Sherlock9 I know Clojure just from doing random stuff

If that helps

Nathan Merrill

@Pavel look up at my code I just posted

Sherlock9

@quartata I'm reading How to Design Programs now, but I'm also trying to learn the original flavor of Lisp as well

Pavel

But what does defer do

quartata

You mean Common Lisp?

Sherlock9

I may look at Clojure later

@quartata Yeah, probably. I'm very new to Lisp

Nathan Merrill

4:03 AM

@Pavel oh, it makes the function execute after the function returns

Sherlock9

I just heard that McCarthy's paper starts with 25 functions and everything else is built on that. Wanted to see it for myself

Nathan Merrill

func c() (i int) {
    defer fmt.Print(2)
    fmt.Print(1)
}

this prints 1, then 2

quartata

Does it happen synchronously after the return?

Reminds me of this:

Nathan Merrill

yes, in reverse order

(of order of defers)

quartata

void c() {
  scope(success) { writeln(2); }
  writeln(1);
}

That's D. They're called scope guards.

Pavel

4:08 AM

Why not just move the function to the end?

Sherlock9

Or rather, to quote TV Tropes (this page)

> The Common Lisp language, although its syntax can be rather daunting, has the unique property that any feature of any programming language can be added to it - yet the compiler/interpreter is tiny and supports only 25 commands.
Why? Because one of those commands lets you create a new language construct, and provide a Common Lisp program that expands that construct into a simpler one. This can then be expanded again, and so on until the program contains only those 25 commands. Essentially, it implements the compilation process itself as a language feature, meaning that the compiler is infi…

Conor O'Brien

func c() (i int) {
defer fmt.Print("done");
return 1;
}

Sherlock9

And I wanted to see that for myself

Conor O'Brien

I probably botched the code since I don't know go

Nathan Merrill

@Pavel a good example is opening a file. Your function may have multiple exit points, but you always want to make sure the file is closed

Pavel

4:10 AM

Ah, makes sense,

Nathan Merrill

another is that you may have a condition to call defer, or put defer in a loop

quartata

There's also scope(failure) which occurs only on error or scope(exit) which is either way.

Nathan Merrill

and you don't want to call that condition at the end

Sherlock9

So do you guys know of a Common Lisp tutorial or guide or some such that I can look at?

Nathan Merrill

@quartata failure is defined by an exception?

Pavel

4:10 AM

codegolf.stackexchange.com/a/107205/60042 I've been refreshing this Dennis answer for a while, waiting for it to reach up-arrow notation levels of golf.

quartata

@NathanMerrill Yes.

Nathan Merrill

I like that much more than the common try{} finally{}

quartata

Me too. Pytek is stealing them.

Pavel

I have never used finally. Does this make me a bad coder?

Nathan Merrill

or you've never dealt with file handling :)

Sherlock9

4:14 AM

Hm, seems better than Python's try, except, finally keywords

Nathan Merrill

@quartata I'm struggling to find a use case for success

like, when would you want to execute something only if the function was successful

Pavel

No, I've dealt with file handling. Read, copy contents to a String, close.

H Walters

finally is a crutch for languages lacking RAII

Pavel

Done.

RAII?

quartata

@NathanMerrill I have one somewhat amusingly: unit tests here you eant to fail if it doesn't throw an error

resource acquisition is initialization

H Walters

4:16 AM

Best to look it up; it's actually misleading to say what it stands for :)

quartata

I usually do this: try { ...; Assert.fail(); } catch (Exception e) {}

Ugly as all hell though.

Nathan Merrill

@quartata what is "failing"? like, do you return false, or do you throw another exception?

Pavel

That's horrible, yet strangely resembles something I wrote once.

Sherlock9

I think Python sort of put that in. You have with keyword now, which (for files anyway), closes a file at the end

Let me find the notation

quartata

@NathanMerrill As in fail the test. Depends on your test harness

Nathan Merrill

4:18 AM

right, I was curious in your case

or, better put, whether you can throw an exception inside of a scope

Sherlock9

with open("x.txt") as f:
    data = f.read()
    # do something with data

Nathan Merrill

and if you can does that get caught inside of a error scope?

quartata

@Sherlock9 I hate this syntax.

Pavel

for (int i=0;;i++) {
    try {
        System.out.println(list[i]);
    } catch (IndexOutOfBoundsException e) {
        break;
    }
}

quartata

Yet another level of indentation

Pavel

4:20 AM

Actual thing I did when I was learning programming for the first time.

Nathan Merrill

I don't like with either. It's not just about the extra whitespace, it forces me to stay in the block while I keep the file open

El'endia Starman

Oh wow, the nostalgia is strong with this one. imgur.com/gallery/pRcG0

Pavel

Actually, I don't think I knew what the exception was called. Probable just said Exception e.

Nathan Merrill

which is an awesome thing about RAII: when the object dies (no matter the scope), the file is closed

Sherlock9

@quartata What's wrong with the syntax?

quartata

4:21 AM

@Sherlock9 As Nathan said you have to stay inside the block

Sherlock9

Oh, I see. I usually just do file read and get out of the with block immediately

Or readlines

quartata

That's fair.

Pytek's \slurp will make that one step

Nathan Merrill

right, and that's what I do as well, but that's not always optimal (when dealing with large files, or wanting to incrementally read it)

@quartata I'm always amazed at how tough it is to read an entire file into a string in most languages

quartata

I know right?

Nathan Merrill

like, seriously, that's 90% of all use cases

H Walters

4:24 AM

Really? 90% of your use cases?

quartata

One of the few things Perl 6 did right. slurp "file". Done.

Nathan Merrill

no, 100% of mine. 90% of the world's :P

H Walters

I'm not complaining, or challenging... just kind of surprised

Nathan Merrill

I rarely want to read part of a file

H Walters

Ah, you're weighting the average... quite often I'm parsing the file while reading it, or reading chunks

El'endia Starman

4:25 AM

@HWalters Yeah. What else are you gonna do with a file? Read it one line at a time? It's very common to read the whole file in at once and then do string processing on the contents.

Dennis

@VoteToClose What have you done ?!

H Walters

@El'endiaStarman I don't doubt it's common; it's just the 90% use case that's high for me personally

quartata

Often times I just want to parse JSON or something. Python thankfully lets you pass in a filehandle and closes it for you but in most languages I just want to slurp and jsonify

El'endia Starman

(How I picture VTC when they see that message.)

Pavel

@El'endiaStarman What what?

What did VTC do?

El'endia Starman

4:28 AM

@Pavel Yeah, basically.

H Walters

@El'endiaStarman But no... usually it's not "line at a time" for me either... it's more "logical data piece at a time", but I don't tend to work with webby stuff a lot

Pavel

I'm confused

quartata

Make an addictive challenge it seems

Dennis

I just know I won't be able to get any rest before the denominator hits 256!.

Pavel

xaxaxaxaxaxaxaxaxa

quartata

4:33 AM

Don't think that's possible sadly

Pavel

Surely there's an obscure bash extension someone made to throw moar error codes

quartata

Man now I wish I made that languagr that outputs only via exit code

Speaking of which @VoteToClose did you ban signals?

Pavel

yes

quartata

OK cool. We talked about that earlier in chat

Pavel

I think

quartata

4:37 AM

I had a score of 7 * 10^-19 otherwise :P

Pavel

That would cause you to be beating Dennis

What makes you think you're allowed to do that

Qwerp-Derp

What it says no sdk

Pavel

@Qwerp-Derp file->project structure

(will give more instructions when intellij boots)

Qwerp-Derp

it says no project sdk

i don't understand why

i have java installed

Pavel

Doesn't detect it automatically

quartata

4:39 AM

I see @DigitalTrauma kind of salvaged the idea though

Pavel

File->Project Structure->SDKs->'+' icon->locate JDK

Should be in Program Files on windows

@Qwerp-Derp does that work?

Qwerp-Derp

what where is locate jdk

i have java runtime environment but not anything else, does that help?

also its 64 bit not 32 bit if that helps

Pavel

Oh

@Qwerp-Derp You have to install the JDK

oracle.com/technetwork/java/javase/downloads/…

The java runtime environment and the sdk are not the same thing

Qwerp-Derp

what

kk

Well that's inconvenient

quartata

JRE is just the interpreter. JDK has the compiler.

Qwerp-Derp

4:44 AM

32 bit or 64 bit?

Pavel

32 bit or 64 bit system?

Qwerp-Derp

Oh OK

ATaco

Gosh we're active right now.

quartata

It's not like end users need the compiler and it stops source code viruses (although Java is portable anywas)

Pavel

Wait, @Qwerp-Derp, you can also get the java 9 pre-release if you want

It comes with a REPL and other neat features

Qwerp-Derp

4:46 AM

Wait link pls

I have Java 8 runtime already

Pavel

Looking for it, one sec

Qwerp-Derp

I'm installing jdk 8

Pavel

The JDK includes the required JRE

Qwerp-Derp

wait what

so i can uninstall the jre?

Pavel

Yes

jdk9.java.net/download

Actually, I'm not sure

You probably shouldn't unless you're low on disk space

Qwerp-Derp

4:48 AM

nah i should just use jdk8 for now

it includes lambdas right?

Pavel

Yeah

Qwerp-Derp

Yey then I can use runnables as lambdas

Woot

Pavel

Sorta. After boilerplate, lambdas are actually longer than normal functions.

ATaco

And lua still doesn't have a good syntax for anonymous functions.

Pavel

REPL tho

ATaco

4:50 AM

We have load"print(...)" which is equivalent to function(...) print(...) end

Pavel

So... eval?

ATaco

Almost.

IIRC eval simply does it, where as load returns an anonymous function.

quartata

Lua has anonymous functions

local x = function()
  ..
end

ATaco

Yeah, but they're bytey

the load method is the same, but smaller.

what I would like is an x:=expression option

quartata

Oh, kind of like Pytek's <:

Qwerp-Derp

5:24 AM

How do I import stuff in IntelliJ?

Pavel

@Qwerp-Derp What do you need to import?

Qwerp-Derp

Processing's main library

Pavel

Ok. file->project structure->global libraries

Qwerp-Derp

How do I start a project from scratch with the default things

What does the base class thing mean also

I don't understand

Pavel

Base package you mean

Qwerp-Derp

5:35 AM

@Pavel Halp pls

Yeah

Pavel

First of all, File->new

Qwerp-Derp

Mmhmm done that

Wait hang on

What is com.company

Can I change that? If so what should I change it to

Pavel

You can change it to anything, but standard is com.<YourName>.<ProjectName>

If anyone wants to import files from the project, they'll do it with import com.<YourName>.<ProjectName>

This will create a line reading package com.<bla>; at the start of every class. Everything with the same package name can access all package-private variables.

(package-private is when you exclude public/private/protected)

orlp

@xnor I tested my 'crack' in my usual Python calculator environment

Pavel

@Qwerp-Derp I forgot the most important thing

orlp

5:43 AM

which contains sqrt

that's why I got confused

Pavel

You can leave it blank for small projects and not worry about it

Qwerp-Derp

Ah OK

Uhh I want to separate some files from my main "sketch"

How do I do that?

Pavel

Oh. Then you do need packages.

Let's assume your package is called com.sketch.

Qwerp-Derp

Uhhuh

Pavel

Create new class you want separate, and set it's package declaration to com.sketch.foobar

This will show up as an error. Put your cursor there and click alt+enter, this should give you the option to move it to it's own package

Qwerp-Derp

5:48 AM

What's foobar?

Pavel

Anything

Qwerp-Derp

Oh

Pavel

From then on, you have to import it to reference it, however it doesn't have to import whatever is in the base package.

You probably don't need to do that.

Qwerp-Derp

Ah

Pavel

Likewise, it can access package-private variables in main but not the other way around

What are you making?

Qwerp-Derp

5:49 AM

Making Trees

Using stuff from Processing

Pavel

Ok. That's probably simple enough you don't need to worry about separating your classes anyway.

The namespaces are separate anyway

And it's not like anyone will ever need to import Trees.

Qwerp-Derp

Yeah, but I have a couple of classes like buttons and progress bars

I want to put them in a separate folder

Pavel

Yeah, then you have to put them in seperate packages.

Qwerp-Derp

How do I do that

Pavel

Do you have a project created with a base package?

Qwerp-Derp

5:53 AM

Yeah

Called com.qwerpderp.trees

Pavel

In the right panel, right click the folder com.qwerpderp.trees and select new->package

Packages are folders

Qwerp-Derp

I got it don't worry

I already did it

Pavel

Oh, k. Create a new java class in that package and just set the package declaration to the new package instead of the base one.

IntelliJ might have done that automatically

Qwerp-Derp

Ah

What variables should be public and what should be private?

@Pavel?

Pavel

public variables can be accessed by anything, including anyone trying to modify the execution of Trees externally.

Use them as little as possible

Qwerp-Derp

5:59 AM

??? So should I make everything private?

What's protected?

Pavel

If you don't include a scope declaration (package-private), it can be accessed by everything in the same package

Protected means only accessible by subclasses

In general, select the most restricitve one you can.

Private when possible, protected if there are subclasses that need it, package-private if everything in your program needs to access and modify it frequently.

wat

yayy

inexpensivecomputers.net/product/bhc-150-basic-home-computer

hello @EᴀsᴛᴇʀʟʏIʀᴋ

orlp

@wat huh

wat

@orlp ?

orlp

why did you link that

wat

6:08 AM

Earlier I was talking about how i listed it on Amazon, I just now input it into my website

Pavel

@Qwerp-Derp Public is for when you have something in a subpackage you need accessible outside of that package.

wat

@Pavel ?

I know what public does

Pavel

Just making sure you didn't get the idea to make everything private.

wat

I think you have confused the chicken and the duck

Pavel

Oh, yeah

Qwerp-Derp

6:20 AM

@Pavel Ah OK

Destructible Watermelon

6:35 AM

hi

VoteToClose

7:08 AM

@Dennis I am not apologizing. :3

@quartata Yes, I banned signals.

orlp

7:44 AM

@VoteToClose that piques my interest

in what context

Fatalize

7:58 AM

@ais523 In which language would you write the parser?

Destructible Watermelon

...

my wizard has the spell light

                   ----------
                  /          \
                 /    REST    \
                /      IN      \
               /     PEACE      \
              /                  \
              | ***************  |
              |      59 Au       |
              |    killed by     |
              |  kicking a wall  |
              |                  |
              |                  |
              |       2017       |
             *|     *  *  *      | *
    _________)/\\_//(\/(/\)/\//\/|_)_______

when you're a wizard who starts with light, and accidentally wields a cursed axe

New Main Posts

8:24 AM

0

Q: "Apple activity tracker" clock, In Ascii

Once, I've seen an activity tracker of the Apple watch. It looked very well-designed. And it seems, there is already a watchface of its theme! This challenge is about it too. The Challenge Your code should read time in any format, and output an ascii art like this. For example, if the time...

mınxomaτ

9:14 AM

Yahoo open-sourced it's CI

Erik the Outgolfer

9:41 AM

I clicked this starred message... only to find a considerable amount of noise around.

Stewie Griffin

10:48 AM

We had the alphabet, now it's clocks...

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

This might be an "impossible" challenge, but I want to see if anyone thinks it can be done. I'm ready to change almost everything, for instance: Let the functions do something other than arithmetic, only have one function ... Note: Please vote on this based on the idea, feasibility and whether ...

New Main Posts

11:16 AM

0

Q: Batch - Addition logic puzzle

Take two random inputs and output the factorial of those two numbers added together in the least amount of bytes. (In batch.)

logic

TuxCopter

Hai

New Main Posts

11:43 AM

0

Q: Hello World! generator

Often I need a simple Hello World! program to show some basic concepts of a programming language on my travels. As I usually travel only with light luggage I can't to carry a Hello World! program for each language. So a program that generates Hello World! programs in as many languages as possible...

code-golf hello-world

0

Q: java i need a program that finds out the usage duration of a machine from a given array and then select one user who uses it the most

usage duration date name start end 05:55 05:59 30.12.16 Mr.Rk Nair 06:9 06:55 30.12.16 ms.AAsha Jha 07:00 08:56 30.12.16 Ms.Rani Kaur

javascript

orlp

Gus knows what he wants

►

2

aww

Fatalize

12:40 PM

I would like to add "cute animal videos/pictures" to the list of things that are noise

5

flawr

12:58 PM

But what is the pont of posting pictures of animals that are not cute???

El'endia Starman

I think the idea is to not post pictures of animals without reason at all.

trichoplax

You could argue that cuter animals constitute more noise, since they are more difficult to ignore...

El'endia Starman

1:14 PM

@Mego books.google.com/ngrams/…

Nathan Merrill

1:24 PM

The Error code challenge is another good one with unobservable requirements.

flawr

@El'endiaStarman books.google.com/ngrams/…

El'endia Starman

@flawr What the heck was Mego doing in 1820?!?

5

Nathan Merrill

According to Google translate, it means "My" in Polish

Fatalize

And to
(archaic) gentle, mild, peaceable
in Spanish

Nathan Merrill

books.google.com/ngrams/…

Same query, case insensitive

Fatalize

1:33 PM

:(, both are not words so I don't see why I'm last

El'endia Starman

@NathanMerrill Awww yeah, that's more like it! :P

Fatalize

Reality check for me: This is a code snippet: +₁ᵐ Can you guess what it does based on the symbols?

El'endia Starman

I can't really tell what the third one is.

Nathan Merrill

Add two boxes

Fatalize

it's a superscript m

Nathan Merrill

1:37 PM

(The second and third character don't load on mobile)

Fatalize

@NathanMerrill Oh… I was about to be sad. the second is a subscript 1 and the third is a superscript m

Sherlock9

My first guess from knowing Jelly is "add whatever subscript 1 means and exponent by the right argument". My second guess is "subscript 1 is a modifier on + and then exponent by the right argument". My third guess is "add then a modified exponent".

Fatalize

Some ideas are there, that's pretty reassuring

The answer is "Map increment"

So you were right that subscript 1 is a modifier on + (+ by itself is sum) / add whatever subscript 1 means

Anonymous

@El'endiaStarman Yep, it's really funny

Anonymous

@El'endiaStarman Shh, don't give away my secret

Anonymous

1:51 PM

@Fatalize That's definitely not accurate :P

Nathan Merrill

OK, I'm reading up on async/await, and if I understand correctly, "await" immediately returns with a promise that resolves when the await resolves and resolves with the value that you return

@quartata how does NodeJS force it down your throat? Do they simply have promises everywhere?

That said: it seems weird that the "async" keyword is needed. If I use the word "yield", I dont need to put "generator" in my function definition

Wheat Wizard

2:12 PM

@Qwerp-Derp btw there is no longer an active bounty on golf you a quine for great good

Business Cat

What's more useful for a range function in a golfing language; 0 to n exclusive, or 1 to n inclusive?

trichoplax

Do you have a symbol spare so you can have both?

Anonymous

@BusinessCat Actually uses both. They both have their merits.

Anonymous

Though if you can only choose one, and you have vectorized increment, go for [0,n)

Anonymous

So that [1,n] is two bytes

Business Cat

2:16 PM

Hmm, I'll probably have both

Planning to use a code page so I'm sure there'll be a spare symbol

Nathan Merrill

Alternatively, 0 to n and m to n would be a useful pair

Business Cat

Yeah there will definitely be m to n

So maybe it could be one for [0, n) and one for [m, n], so you can just use 1 as m

Nathan Merrill

Using a variable makes it inclusive? That seems like a bad idea

Business Cat

Probably, tbh

Nathan Merrill

If possible, just override your 1 symbol so that if it is followed by a m to n, it makes the m to n inclusive

Gabriel Benamy

2:21 PM

how do people continually say "yes, I think a community called Code Golf is the best place to put my programming questions"

Business Cat

That sounds weird

@GabrielBenamy "Because I can't figure it out so it's a programming puzzle"

Fatalize

To be fair the site's first word is "Programming"

Gabriel Benamy

and my DVR instruction manual has a section on "programming your dvr" let's call up verizon and see if they can help me with this batch script to calculate factorials

Anonymous

@GabrielBenamy Do you want your DVR to catch on fire?

Gabriel Benamy

Halt and Catch Fire

In computer engineering, Halt and Catch Fire, known by the assembly mnemonic HCF, is an idiom referring to a computer machine code instruction that causes the computer's central processing unit (CPU) to cease meaningful operation, typically requiring a restart of the computer. It originally referred to a fictitious instruction in IBM System/360 computers, but later computer developers who saw the joke created real versions of this instruction for some machines. In the case of real instructions the implication of this expression is that, whereas in most cases in which a CPU executes an unintended...

Anonymous

2:24 PM

So that's a yes. I can help you out with that.

trichoplax

2:46 PM

@GabrielBenamy Maybe we could ask them

"How did you find this site?"

Anonymous

2:56 PM

@trichoplax People have asked before. It's always the same outcome: no response, deleted question, never see the user again

trichoplax

Oh well

quartata

@NathanMerrill Even something as simple as reading a line from stdin involves registering a callback. They're not even considerate enough to provide promises

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@wat what's the ping for?

I wasn't even in this chat then

trichoplax

I suppose that's inevitable. "Thanks for not reading any of the information or even the title of the site. Would you mind taking some time to fill in a survey?"

Nathan Merrill

@quartata so, to read input, you pass in a function that is passed the input?

quartata

2:59 PM

Yes. process.stdin.on(..)

Anonymous

@trichoplax Pretty much :P

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