The Nineteenth Byte

Eᴀsᴛᴇʀʟʏ Iʀᴋ

3:06 PM

cool

chat is dead

Geobits

All rooms must die.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

>_>

Geobits

What is dead may never die?

Eᴀsᴛᴇʀʟʏ Iʀᴋ

idk

Rainbolt

How do you kill that which has no life?

Geobits

3:09 PM

Death is but the next great adventure.

Quill

@Geobits Java

Tables in HTML

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@Rainbolt with a wooden stake?

Geobits

I'm pretty sure both those are still used. You can debate their merits, of course.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@Geobits regex parsing HTML.

Geobits

I'm not sure if that's even a thing. More like a verb.

zyabin101

3:12 PM

@EᴀsᴛᴇʀʟʏIʀᴋ H̳̻̓̋͐ͤ̀Ế̴̘̼́̈́̒͗͒͑̂́ ̨̥̗͍̦͈̙͓ͦͤ̽C̗͍̠̝͔̾ͣ̚Ơ̛͈̙̪͈̭̜̩̫̋ͭ̄ͭͪ̓͢M̵͓̼̤̠̰͍ͯ͑E̵ͮ͑ͥ͋̒̃͌ͯͮ͏͕̭͔̦̱͎̥̰S͓̠̿̾̔ͩ̈́͋̀̈͠‌̰͎̞

El'endia Starman

Capacitors and Capacitance: Capacitor physics and circuit operation

►

I finally understand how capacitors work! :D

wizzwizz4

:-)

El'endia Starman

By the way, perfect use-case for increasing the speed of the video.

wizzwizz4

I've just noticed. My retrocomputing profile has 1 gold, 2 silver and 8 bronze.

zyabin101

3:28 PM

@wizzwizz4 I wish there was a badge level between bronze and silver.

You could get 1 gold, 2 silver, 4 <badge level between bronze and silver> and 8 bronze!

@Doorknob Can you please status Babble?

Doorknob

indefinite hiatus?

Quill

it needs 5 bronze instead

zyabin101

@Doorknob D:

Quill

@Doorknob -1 not sassy enough

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@El'endiaStarman noice!

Doorknob

3:31 PM

@Quill $answer: eventually;

PhiNotPi

Well, I got a quantum fourier transform working.

zyabin101

@PhiNotPi Publish on the quantum playground.

PhiNotPi

Any suggestions what I should transform with it, if I run it on the actual IBM computer?

Eᴀsᴛᴇʀʟʏ Iʀᴋ

http://codegolf.stackexchange.com/questions/tagged/ಠ_ಠ redirects to the new questions page.

ಠ_ಠ

Rainbolt

The first link goes to Code Review

Quill

3:37 PM

@EᴀsᴛᴇʀʟʏIʀᴋ it probably strips the unicode out

Nathan Merrill

@El'endiaStarman language design. A common problem is "count the number of times you do X until Y is true". Is there some sort of syntax that would make this better?

aka, the common solution is:

x = 0
while (cond):
    x++
    other stuff

x = count (cond):
    other stuff

that could work

PhiNotPi

@zyabin101 I'm not sure how to do that.

I have the IBM "quantum score"

zyabin101

>_>

Ah, so you have the quantum score. I don't know how to do that.

mınxomaτ

@zyabin101 qCAD supports that AFAIK.

El'endia Starman

@NathanMerrill Hmm. That is a pretty common pattern.

zyabin101

3:44 PM

@PhiNotPi How does it look?

Nathan Merrill

@El'endiaStarman it whitespace significant in your language?

regardless, the really cool thing about making while loops return the number of times they iterated

zyabin101

@mınxomaτ Where is qCAD?

Nathan Merrill

is that if they didn't iterate at all, they return 0 (falsy)

El'endia Starman

@NathanMerrill Only for separating tokens.

Nathan Merrill

so you could do

mınxomaτ

3:45 PM

@PhiNotPi You can gist the code output of the score.

@zyabin101 qcad.osdn.jp

Nathan Merrill

if (!while(cond){
    do stuff
    }){
    do if while didn't run
   }

zyabin101

@mınxomaτ Ah.

wizzwizz4

Implementing programming languages is fun.

PhiNotPi

h q[2];
cx q[1], q[2];
h q[0];
t q[1];
tdg q[2];
t q[0];
cx q[1], q[2];
h q[0];
h q[1];
t q[2];
t q[0];
h q[2];
h q[0];
tdg q[2];
tdg q[0];
h q[2];
h q[0];
t q[2];
tdg q[0];
h q[2];
h q[0];
t q[2];
tdg q[0];
h q[2];
h q[0];
tdg q[2];
t q[0];
h q[2];
h q[0];
t q[2];
t q[0];
h q[2];
h q[0];
t q[2];
cx q[0], q[2];
tdg q[2];
h q[2];
tdg q[2];
h q[2];
t q[2];
h q[2];
tdg q[2];
h q[2];
tdg q[2];
cx q[0], q[2];
cx q[1], q[2];
h q[1];
h q[2];
cx q[1], q[2];
h q[1];
h q[2];
cx q[1], q[2];
cx q[0], q[2];

El'endia Starman

One possibility is to keep track of how many iterations loops ran for and provide that to the user through the use of a special command.

Nathan Merrill

3:47 PM

yeah, but then you run into scoping issues

but considering your use of ~ and _ that doesn't seem to be super important to you

El'endia Starman

Could restrict them to scopes like other variables.

Nathan Merrill

while(){
   stuff
}
while(){
   otherstuff
}

if you wanted to access the count of the first while, you'd need to do a a = magic command before the second

PhiNotPi

Usage notes: the input qubits are [q2,q1,q0] and the output qubits are [q0,q2,q1] in those orders (most-significant first).

Nathan Merrill

also true for inner loops

TimmyD

@NathanMerrill Not if you treat it like the error array in .NET or Java or whatnot

Nathan Merrill

3:50 PM

keeping an array of values?

way too much overhead

El'endia Starman

@NathanMerrill I'm not sure what you think ~ does (maybe you're thinking of ~>, which indeed used to be ~, which feeds an initial argument list into a chain of functions), but _ will always take values from a special "feed" list provided by the outer scope.

TimmyD

Well, having the user wanting how many iterations a loop ran is already asking for some overhead.

zyabin101

Oooooh, just installed qCAD.

It's cool.

El'endia Starman

For loops basically give you that automatically. You can usually look at the value of the loop variable.

TimmyD

Problem solved - only allow for loops

El'endia Starman

3:52 PM

So maintaining such an array of iteration counts would have as much overhead as changing each while loop into a for loop.

Nathan Merrill

@El'endiaStarman I may be wrong with ~, but I'm not a huge fan of auto-assigned variables like _, firstly because they seem like magic, secondly, because they have scoping issues.

zyabin101

I now have a simulated quantum computer at my hand.

Without registration or sane graphics card.

It's wonderful.

Nathan Merrill

for range():
    for otherrange():
       a = _
    b = _

wizzwizz4

Who likes old computers?

Note: I am not selling any.

Quill

I followed the retrocomputing beta in A51 but I never got into the site once it launched

wizzwizz4

3:55 PM

@Quill You can join now!

Nathan Merrill

I mean, in the first case, its easy to see what a is

Quill

I joined the site, I just never got around to contributing

Nathan Merrill

but b?

El'endia Starman

@NathanMerrill Oooh, I should've put "scope" into quote marks. a there would come from otherrange() and b would come from range().

Nathan Merrill

but do you scope outside of loops?

for range():
    for otherrange():
       a = _
    b = _
    c = a

is a defined?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

3:56 PM

@zyabin101 I see. I still like having control to edit the HTML at will and knwoing what my program does

El'endia Starman

@NathanMerrill Yes. a is just a normal variable.

Nathan Merrill

therefore, _ has weird scoping rules

it magically gets assigned

when you leave a loop

wizzwizz4

@Quill Contribute if you want free badges. I got a gold one on my first post!

El'endia Starman

Let me translate your code into Python.

Nathan Merrill

actually, do you have shadowing of variables at all?

Quill

3:58 PM

@wizzwizz4 meh

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@zyabin101 it's a BF interpreter iirc

El'endia Starman

for x in range():
    for y in otherrange():
        a = y
    b = x
    c = a

No mystery now is there?

wizzwizz4

"Gold badges" -> "meh"
?!?

Nathan Merrill

right, but you're using _ twice

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Zgarb whoa. that's interesting.

El'endia Starman

3:59 PM

_ is only "fed" from what it's inside.

TimmyD

It's not getting re-assigned, it's just context switching.

Nathan Merrill

right, the inner loop _ is shadowing the outer loop _

Eᴀsᴛᴇʀʟʏ Iʀᴋ

HAI @CᴏɴᴏʀO'Bʀɪᴇɴ

Cᴏɴᴏʀ O'Bʀɪᴇɴ

HAI

Nathan Merrill

but that doesn't happen with any other variable

for range():
    a = 1
        for otherrange():
            a = 2
    b = a

TimmyD

4:02 PM

If I was a betting man, I'd wager that the compiler/interpreter in the background is treating them as two separate variables, like how El'endia explicitly pointed out.

El'endia Starman

You would win that bet.

TimmyD

Just because it's a shorthand notation for "the current thingy" doesn't mean it's a literal variable _

Nathan Merrill

probably

but it feels and acts like a variable

actually, what happens if you try to assign to it

Eᴀsᴛᴇʀʟʏ Iʀᴋ

TIL avocet is a bird.

Avocet

The four species of avocets /ˈævəsɛt/ are a genus, Recurvirostra, of waders in the same avian family as the stilts. Avocets have long legs and long, thin, upcurved bills (giving their scientific name Recurvirostra) which they sweep from side to side when feeding in the brackish or saline wetlands they prefer. The plumage is pied, sometimes also with some red. Members of this genus have webbed feet and readily swim. Their diet consists of aquatic insects and other small creatures. They nest on the ground in loose colonies. In estuarine settings they may feed on exposed bay muds or mudflats. The...

@AlexA. are you sure you are a magpie, not an avocet?

El'endia Starman

@NathanMerrill That'll error, most likely.

zyabin101

4:03 PM

An avocet.

TimmyD

In PowerShell it's treated as a variable.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@NathanMerrill it works

El'endia Starman

It's meant to convey the concept of "fill in the blank".

Cᴏɴᴏʀ O'Bʀɪᴇɴ

at least, in the REPL

Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC v.1600 32 bit (In
tel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> _ = 5
>>> _
5
>>> _ = -3
>>> 3
3
>>> _
-3
>>>

TimmyD

PS C:\Tools\Scripts\Golfing> 1,2,3|%{$_;$_=0;$_}
1
0
2
0
3
0

El'endia Starman

4:05 PM

@CᴏɴᴏʀO'Bʀɪᴇɴ In the Python REPL, yes.

We were talking about Pytek's _.

TimmyD

Just like how with a for loop you can re-assign your counter variable.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

oh

Nathan Merrill

so, lets say I wanted to use the squares of 1 through 10

El'endia Starman

Though Nathan was using Pythonesque pseudocode.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

that's why :p

Nathan Merrill

4:05 PM

for range(10):
    _ = _ * _

I couldn't do that

TimmyD

So if Pytek should make any lick of sense, it should follow already established standards. And if Python and PowerShell both agree on something, it's pretty much an industry standard. ;-)

Nathan Merrill

I'd have to do

for range(10):
    a = _ * _

El'endia Starman

Why not just stick _^2 wherever you would put a?

Nathan Merrill

@TimmyD there are often good reasons to break standards. I'm ok with breaking standards, as long as its for a good reason

Cᴏɴᴏʀ O'Bʀɪᴇɴ

>_> it's probably a proof of concept

Nathan Merrill

4:07 PM

@El'endiaStarman you're trying to save calculations

El'endia Starman

@TimmyD I decided long ago that Pytek wasn't necessarily gonna follow any traditions or standards. :P

Nathan Merrill

aka, you're going to use the value multiple times throughout the function

TimmyD

@CᴏɴᴏʀO'Bʀɪᴇɴ Nothing is greater than the current item is greater than nothing

El'endia Starman

Well, then what's the problem with assigning to a new variable? You usually have to (or should) do that anyway.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@TimmyD that sounds like a python comparison

0>x<0

El'endia Starman

4:08 PM

I could make _ assignable. We'll see.

TimmyD

@CᴏɴᴏʀO'Bʀɪᴇɴ You typed >_>

Nathan Merrill

@El'endiaStarman there's technically no problem. Programmers simply often do that using the same variable, but it would be surprising if it didn't work on _

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@TimmyD ... ah

Nathan Merrill

but that said

Cᴏɴᴏʀ O'Bʀɪᴇɴ

so _ is the current value in a for loop?

Nathan Merrill

4:09 PM

I think if you are going to _ magic, you should make it act different

so, I'd be in favor of it not being assignable

El'endia Starman

Alright, that was my original plan.

TimmyD

_ is a placeholder variable for "current item" in lots of languages

El'endia Starman

@CᴏɴᴏʀO'Bʀɪᴇɴ That's one use, yes.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Ah

I second the idea of nonassignable

El'endia Starman

@TimmyD && is logical AND in lots of languages too. ......except Python. (And Pytek.)

Nathan Merrill

4:10 PM

just making sure you realize the implications :)

now, back to my original idea

a = for something():

TimmyD

Not PowerShell! We get to use -and and -or etc. We do get to use ! for logical-not, though.

Nathan Merrill

or while

El'endia Starman

@NathanMerrill Yes, the problem of knowing how many times a loop ran.

Nathan Merrill

it basically makes for/while loops a function that returns the number of times it ran

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@TimmyD -and and -or look like flags. is that why?

El'endia Starman

4:11 PM

Well, Minkolang has the command i that pushes the loop's counter on the stack.

PhiNotPi

@mınxomaτ so... my fourier transform works great in the simulator, but terrible on the real device, like totally wrong.

Nathan Merrill

@El'endiaStarman hmmm, the current counter is useful, but it doesn't ever contain the number of iterations

TimmyD

@CᴏɴᴏʀO'Bʀɪᴇɴ Kinda. There's a whole slew of operators that have - at the front ... -replace ... -split ... etc.

Nathan Merrill

aka, if & stored the current counter, you'd have to assign it to a variable in the loop, and then add one after the loop

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@TimmyD is that because the parser looks for a symbol then a string of letters or something?

El'endia Starman

4:13 PM

@NathanMerrill Yeah, to do that, I basically push the counter and then break the loop.

Nathan Merrill

for some_gen():
    a = &
iterations = a+1

El'endia Starman

Really, it seems to me like the main problem with keeping an array of iteration counts is that it's a little harder to get counts of inner loops. So you could either "scope"-restrict or make the array a little more magical by allowing some sort of indexing to get the count of the inner loop.

TimmyD

@CᴏɴᴏʀO'Bʀɪᴇɴ I think it really stems from the fact that | represents the pipeline, and since PowerShell is a shell/language hybrid, the pipeline is really important. As a result, something other than || would be needed for "or", so I think the operators followed from there.

Do note that -not is valid, too, we just get an alias with !

El'endia Starman

Like I've said before, the overhead will be minimal, I think. Just convert every while loop to a for loop and you basically have that exact same overhead.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@TimmyD oh. couldn't they've built the parser such that two || is a pipeline? I don't think two pipelines could appear next to each other... right?

TimmyD

4:16 PM

Possibly. It's certainly a style decision, and they probably just chose this for clarity.

El'endia Starman

@CᴏɴᴏʀO'Bʀɪᴇɴ I think the point is that they took the shell they already had and integrated a language into it. For backwards compatibility reasons, they chose not to make the pipeline token something else.

Nathan Merrill

for some():
     for this():
          ...
     for that():
          ...

how does that work with arrays?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@El'endiaStarman Ah

El'endia Starman

Supposing that the loops ran twice, thrice, and once each, maybe you could have...

magicarray[0] # 2
magicarray[0][0] # 3
magicarray[0][1] # 1

PhiNotPi

@mınxomaτ I don't know if you can see this link, but here is the realistic simulation and here is the actual execution.

El'endia Starman

4:19 PM

This can be done with a custom Python class, incidentally.

Nathan Merrill

I don't understand that array

so, the first #2 indicates that some() ran twice?

El'endia Starman

Yes.

Nathan Merrill

but if it ran twice, then why didn't this() run twice

mınxomaτ

@PhiNotPi Nope. Can't see. Can you share it somewhere (screenshot etc)?

El'endia Starman

....oh, hmm. Well, my thought was that this() ran thrice the last time, which is the behavior you'd have when you looked at for loop variables.

Nathan Merrill

4:21 PM

ok

if I'm inside some(), then is magicarray[0] equal to 3?

assuming I'm on the second iteration?

also, what happens if that() runs the first time, but not the second?

does it have a value? or is the the count of the first time?

even better question. What happens if that() runs the first time, and this() runs the second?

@El'endiaStarman ^

El'endia Starman

hmm

@NathanMerrill ...yyyes? I suppose so? It could 2 instead, or 1 if it's the first iteration. That would probably make more sense, especially if you consider this in the sense of copying for loops with counters as their variables.

Nathan Merrill

wait...

PhiNotPi

@mınxomaτ okay, so here is the "ideal" result (keep in mind bits 2 & 3 are swapped)

El'endia Starman

@NathanMerrill I would presume that magicarray[0][1] == 0 because it didn't run.

PhiNotPi

Nathan Merrill

4:28 PM

@El'endiaStarman I should clarify. By "didn't run" I mean that there was an if statement that surrounded it that was false

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Zgarb or @quartata (J programming) I can use jconsole <file.ijs> to run file.ijs before entering the environment, but I want to perform a calculation on command line arguments--can I do this? Say I want to add 5 to an argument.

PhiNotPi

Here is the "realistic simulation." There's a lot of noise, but the central hump is still slightly visible.

El'endia Starman

@NathanMerrill Either 0 or None. I guess that's something that would have to be sussed out in actual usage.

PhiNotPi

mınxomaτ

huh

PhiNotPi

4:29 PM

Here are the actual results:

Nathan Merrill

@El'endiaStarman this wasn't what I mean. Inside the loop, magicarray should be [0,1], otherwise, my code has to care how many loops I'm currently nested inside

@El'endiaStarman so, your code is going to look at my code in advance, and count the number of for loops, and then build an array of that size

for some():
     if False:
         for neverrun():
     for willrun()

PhiNotPi

As you can see, the large percentage of 000 makes me think my program was too long for their computer to handle.

Nathan Merrill

after some(), magic array will contain {3, {None, 4}}

TimmyD

@NathanMerrill You're making my brain hurt with the smartness and thinking things.

Nathan Merrill

sorry :)

TimmyD

4:32 PM

:D

mınxomaτ

@PhiNotPi Well, the significant point are still clearly visible. The only result that breaks it is at 000, all other scale very well and have almost a uniform noise floor. I guess the execution time is too long and it get's too noisy

ninja'd ._.

TimmyD

A multi-dimensional array of arrays?

No, that won't work.

PhiNotPi

@mınxomaτ The percentage of 011 is totally out whack, more so than everything else.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

\o/ I found out how to use localhost!

Nathan Merrill

actually

oooh, this is cool

TimmyD

4:34 PM

Assign each loop to a hashtable entry, where its index is its name plus the name and current-loop-count of the parent.

Nathan Merrill

let magicarray be equal to the value of the last statement of the for loop

for some():
     4
b = magic_array

then, b would be an array of 4s

you could call len(b) to get the number of times it ran

and for loops are natural maps

as far as getting inner loop counts, who cares

TimmyD

@NathanMerrill @{'some1this'=2;'some1that'=1;'some2this'=3;'some2that'=1;'some'=2}

Nathan Merrill

gross

you really want to write code to parse that

TimmyD

I didn't say it was pretty, I just said it was a solution.

Nathan Merrill

you have to start writing splits just to use the builtins

lol

TimmyD

4:37 PM

Implementation is left as an exercise for the reader.

Nathan Merrill

enumerate = for some(){
    (&, _)
}

^ that's still my favorite way of doing it

Bald Bantha

what is the significance of "ETIANMSURWDKGOHVF L PJBXCYZQ" in everything in the morse code translator challenges? I can't figure out how some of the programs work, specifically the c# and golf script answers which seem to use a similar technique

Nathan Merrill

also

is there another term like yield or return?

(like a synonym)

it sets the return value

but doesn't actually stop the flow

oooh

keep

no, report

yeah, that's the way to do it

Cᴏɴᴏʀ O'Bʀɪᴇɴ

4:58 PM

@Quill or @Downgoat -- in node js, I have an array of RGB values. How do I save that to a file/convert that to base64 as a PNG?

Quill

no idea

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