The Third Stack

Wheat Wizard

15:17

@Christopher Hello from the Third Stack!

Christopher

Hello

Wheat Wizard

Ok so you understand how Miniflak works right?

Christopher

Yeah Brain-Flak without some operators

<> and [] (and the subsets)

Wheat Wizard

Ok the crutial thing to remember is that Miniflak does not have arbitrary access to its stack. Any access must be determined at compile time.

Christopher

Wait what.

So you cannot access the stack pre-compile?

Wheat Wizard

15:20

In Brain-Flak you can write a program to take n off the stack and remove the nth element from the stack

Christopher

Ok. But in Mini you can't

Wheat Wizard

yes precisely

Christopher

Also you can't cycle stacks correct?

Wheat Wizard

yeah

Christopher

Sweet

Wheat Wizard

15:21

The problem is that that functionality is really useful for quines

Do you know the general quine strategy?

Christopher

Encode half of it and print both halves?

Wheat Wizard

Yes

Christopher

Ok yes

Wheat Wizard

The problem with that for miniflak is that you cant perform an operation on every element of the stack because of the lack of random access, so decoding is not really possible

Christopher

can? Or can't?

Wheat Wizard

15:23

(there is a way but its not simple and really slow)

Christopher

Ok dang. That is interesting

Wheat Wizard

Instead we write an encoding function

Christopher

Huh

Wheat Wizard

This works just like a dictionary in an other language

Christopher

So it has the values of {}[]() in it

Wheat Wizard

15:25

No not quite

we have that too but that is later

Christopher

Oh yay.

Wheat Wizard

this is a chunk of code that takes n off the top of the stack and replaces it with the nth character

Christopher

Is there a way to get input? I cannot find one.

Wheat Wizard

what?

Input to what?

Christopher

Input for the program (aka , for bf)

Double checking I am not blind

Wheat Wizard

15:27

Are you using TIO?

or desktop?

Christopher

Yes

(TIO)

Wheat Wizard

just put it in the input box

Christopher

That makes sense.

Wheat Wizard

there is no way to take input once the program has started

Christopher

So the input just is the start of the stack. Sounds good and please continue

Wheat Wizard

15:29

Ok so we are going to write a function that takes n and gets the nth character

Do you know how an if works in Brain-Flak

Christopher

If top of stack is not 0 run this

Like in BF

Wheat Wizard

I should probably tell you that <...> while banned is the same as ([...]){}

Christopher

Clever

Wheat Wizard

The iff idiom is (({})){(<...>)}{}

this will run ... once if the tos is truthy and no times iff it is false

Christopher

Wow.

Wheat Wizard

15:31

Do you get how that works?

Christopher

Starting to decode it

Wheat Wizard

Ok I'll give you a bit

Christopher

pops stack and adds it twice then while stack is not zero evaluate foo and push 0. Pops stack

Wheat Wizard

yep

Christopher

This is really cool

Wheat Wizard

15:34

another important idiom is not ({}<(())>){((<{}{}>))}{}

this will take the logical not of the TOS

Do you get that one?

Ok I have to take a short break to move

Christopher

Ok I will keep working on understanding

Wow this is making my head hurt.

Wheat Wizard

Ok I'm back

Understanding the idioms is not crucial, it is a good idea but they do what I claim they do.

Christopher

Can you help me understand this. What I got from the first half was you added the result of popping the stack and adding one then evaluate to 0

Wheat Wizard

Ok ({}<(())>) will put a 1 under neath whatever is on top of the stack

Christopher

That is what I figured

The next part was the real problem

@WheatWizard (Totally didn't just run that to realize what it did)

Wheat Wizard

15:44

{((<{}{}>))} is a modified if, if the tos it will replace both the tos and the 1 with zeros

So if the tos is true we will get 0 0 but if it is false we will get 0 1

so {} removes the extra zero on top

Christopher

That is clever

Ah makes sense

Wheat Wizard

I think it is one of the few programs proven optimal in Brain-Flak

anyway we can make a composite of the two idioms if x == 0 do ... with (({})<(())>){((<{}{}>))}{}{(<{}...>)}{}

Christopher

So logical not of input and then the if

Wheat Wizard

exactly

Christopher

I like this language

Wheat Wizard

15:47

:D

Christopher

Is there a number limit?

Wheat Wizard

Nope! :)

Christopher

Yes! Going to answer challenge

Wait. Must infinite loop first

Wheat Wizard

Ok so we can use this new idiom to create our lookup table/function

Christopher

Ah

Wheat Wizard

15:50

All we have to do is implement the following psuedo code
x--
if x == 0 push thing
x--
if x == 0 push thing
x--
if x == 0 push thing
x--
if x == 0 push thing
x--
if x == 0 push thing

Christopher

Clever. Side question. Should `(()){(()){}}` print
4...
3
2
1

Wheat Wizard

No

that will loop without end

Christopher

That was the idea. Ohhhh,

So it will never show the stack

Wheat Wizard

yeah

Christopher

I wanted it to always loop but if it always loops you never see stack

Wheat Wizard

15:53

yeah just like you can't take input any time you can output any time either

Christopher

Curse you challenge!

Wheat Wizard

Ok I'm going to go get lunch with a friend. Hopefully that will give you some time to digest what I have said and give me some time to figure out how I hope to explain the rest.

Christopher

Ok I will be on later today

Around 5:00 PM EST roughly

Riley

If you have questions now, I can answer a few.

Christopher

Thanks for all the help. (P.S I gave you a few deserving upvotes on some challenges)

@Riley Thanks but I have to eat lunch (lasagna brought from home)

Wheat Wizard

16:37

@Christopher I have graph theory then so I will definitely be available then

Riley

19:16

@WheatWizard 115 bytes :)

Wheat Wizard

@Riley Good job, I think you win, I'm not coming back from that

Riley

That's as far as I'm going to be able to go with it. There is probably a way to shave off a few bytes, but I've already spent way too much time on it.

Wheat Wizard

> I'm not coming back from that

113 bytes

I couldn't help myself

Riley

19:39

113 bytes not quite the same as yours.

Wheat Wizard

Yeah I moved ()() when I didn't have to but otherwise they are the same

Riley

Okay. I figured it was something like that.

Wheat Wizard

20:04

@Riley 111

109

PhiNotPi

@DJMcMayhem Prependix or Appendix? Dependix

Wheat Wizard

@Christopher My laptop's battery is going to die before 5 so I wont be able to help you with anything until I get back to my dorm around 10:00 EST.

Riley

@WheatWizard Did you ever figure out why -d isn't working on TIO?

Wheat Wizard

I misspelled something in my code.

I fixed it but it has not been pulled.

Riley

Nice. I could definitely used it for this/

Wheat Wizard

20:13

-d still works @df and output with -d doesn't work

you can do things like @dh, @dv and @dc

We could also ask Dennis to pull

Christopher

20:27

@WheatWizard Oh wow

That sucks

Wheat Wizard

I can help you now. I still have 10%

Christopher

Sadly I have some work to get done :(

Riley

20:40

@WheatWizard Is there still a way to print ASCII (wrapping)?

Wheat Wizard

Craneflak will do it

other than that no

Christopher

How do you print any ascii?

Wheat Wizard

-A

-a to take in ASCII

-c to do both

Christopher

Thanks

Riley

Did Brain-Flueue ever have an interpreter that would print ASCII

Nevermind. It isn't going to work anyway

Christopher

20:47

How do you use flags in tio?

Riley

Click "Arguments", click "add". For example: TIO

Christopher

Thanks

@Riley good challenge for first answer in Mini-Flak?

Riley

@Christopher I'd go through a bunch of examples on the wiki and solve them without looking at the snippet.

Riley

21:09

@WheatWizard 103 bytes

Christopher

@Riley Ok thanks. Uhh i think i broke everything

([()]) should push -1 to stack right?

Riley

@Christopher Yes

Christopher

@Riley tio.run/nexus/brain-flak#@68RraEZq/n//38A

what did i do wrong?

Riley

You have the arguments open. Hit remove on the left.

Christopher

WHAT. Lamest problem ever

Riley

21:15

101 bytes

If you open Debug, you can see why that happens.

Christopher

Thanks

Using mini-flak is hard

Cuz i cannot cycle stack

I am trying to make a counter

For checking equality

({}[{}]) <- subtraction

Riley

Yep

Christopher

Hmm. To multiply first i will figure out cycling x,y -> y,x

Wheat Wizard

Do you want me to tell you?

Christopher

Yes/no

I want to figure it out but I don't know if i can

a hint?

Wait

nvm. idea

Actually a hint would be nice

Wheat Wizard

21:28

@Riley You are a madman. I don't think I can beat 100 but I will try.

Christopher

My idea failed as it needed me to be able to cylce x,y to y,x...

Wheat Wizard

I meant do you want to know how to cycle x,y to y,x

Christopher

Is there a builtin? If not a hint would be what i need

Riley

I was really happily surprised when ({}[][]) happened to produce the number I was looking for at end.

Wheat Wizard

bultin? miniflak only has 6 builtins

it is quite short

Christopher

21:30

@WheatWizard Ok fine give me it

Wheat Wizard

(({}({}))[({}[{}])])

It is also the best know cycle in Brain-Flak as well

Christopher

Gah!

Half way trough my code i forgot what each section does

Wheat Wizard

Nov 30 '16 at 0:16, by Wheat Wizard

Brain-Flak Syndrome: The act of forgetting what your code does before you've even written it.

Christopher

NOO

I thought what i had was working

But the first number cannot be odd

Wheat Wizard

Here is a hint for multiplication. {...} will evaluate to the sum of the values of the iterations.

Christopher

21:43

tio.run/nexus/…

What i have so far

Wheat Wizard

That will find n*2^m

probably not what you wanted

Each time you run you're doubling the second item on the stack

also remember if you want to manipulate the second item you can always just do ({}<...>)

well actually ({}[(...)]{})

DJMcMayhem

What's the shortest 2^n we have? (Stack clean or not)

It seems like it should be shorter than multiplication, but I can't beat 36

Wheat Wizard

32

DJMcMayhem

Sorry, 34

Crap

I meant n^2 haha

I've got (({})){({}<(({}))>[()])}{}{}({{}}) but that's not stack clean and only two shorter

Wheat Wizard

18

^ 1000000000 and I have proven that is the shortest program that squares a number

DJMcMayhem

21:50

Damn

Wheat Wizard

It is imo the most beautiful brain-flak program ever written

DJMcMayhem

I don't even understand how it works

Wheat Wizard

I have to go but I would love to explain it later. It is really cool

DJMcMayhem

It is beautiful though

So I guess n^2 == n + 2 * sum(0, n-1)

Or in other words, n^2 == n + 2 * triangle(n-1)

Ooooooh

That actually makes sens

If you rotate the triangle upside down and attach it to the other triangle, you'd get a polygon of NxN-1 so then you just add N to fill out the top row

Wheat Wizard

Exactly!

DJMcMayhem

21:59

Oh, an even simpler explanation: n^2 == triangle(n) + triangle(n-1) which is well known

That's truly incredible, how did you first find it?

Christopher

22:47

hmmm

hmmmmmmmmmmmmm

Christopher

23:02

YES! ({}({} ({}...) ([{}]))([{}])) allows you to manipulate the third item on the stack. Only problem is it makes the 2nd and third item negative. Fixing that :P

({}([{}] ([{}...]) ([{}]))([{}])) NOW DOES IT. Super happy. It lets you change the 3rd stack item. @WheatWizard

@Riley any ideas on golfing that?

Ofc the new problem is getting the first stack item :P

Riley

23:59

@Christopher ({}(({}( ... )[{}]))[{}]) lets you manipulate the third item. This addes 1 to the third item: TIO

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