The Nineteenth Byte

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22:03

@thejonymyster Generally speaking, sqrt only has one solution, but x^2 = a has 2. Convention is that sqrt takes the positive branch

thejonymyster

right of course

but even if you do say "sqrt has two solutions", thats not the same as "sqrt has one solution which isnt equal to itself"

which is what that message is saying

caird coinheringaahing

"isn't equal to itself" is non-sensical

thejonymyster

(exactly!)

see the message i was responding to:

1 hour ago, by forest

@WheatWizard sqrt(-1) = sqrt(-1) is false though?

DLosc

@cairdcoinheringaahing Let's talk about... JavaScript

thejonymyster

complete and utter NaNsense

caird coinheringaahing

22:09

@DLosc Javascript is non-sensical :P

DLosc

Actually, as much as I would love to poke fun at JavaScript, I think it must be part of the official standard for floats. Python does it too.

att

22:33

677

A: What is the rationale for all comparisons returning false for IEEE754 NaN values?

I was a member of the IEEE-754 committee, I'll try to help clarify things a bit. First off, floating-point numbers are not real numbers, and floating-point arithmetic does not satisfy the axioms of real arithmetic. Trichotomy is not the only property of real arithmetic that does not hold for fl...

caird coinheringaahing

Any final feedback?

Radvylf Programs

Yeah a lot of complains about JS are actually complaints about IEEE floats

Sandbox Posts

A: Sandbox for Proposed Challenges

Make a Brainfuck Interpreter code-golfinterpreter There already is a Brainfuck interpreter question, but it is from 2011 and not up to date with current site standards and vague in places. I have proposed reposting this in chat, and it was well-received. Here goes. Objective Given the Brainfuck c...

Neil

@thejonymyster x => (x => y) is equivalent to !x || (!x || y) but || is associative so that's just (!x || !x) || y or !x || y which is x => y as desired

Steffan

22:50

@DLosc It's even worse in Java, where a string is not equal to itself.

user

It's not a string thing

The value of something is a reference, and reference equality causes that

Which is really really annoying

Steffan

I know

user

But sometimes a string literal can equal itself

@Steffan My bad lol

Try it online!

Steffan

I guess lyal is today. Did we learn Coconut yet or not?

We kind of did like 2 hours before it ended (kind of)

user

Actually wait this one is more bizarre: Try it online!

String interning is wack

@Steffan +1 to learning Coconut again

Bubbler

23:03

@cairdcoinheringaahing Now that the first answer has size 2, "The nth answer should be a starting configuration of cells within an n×n bounding box" is incorrect :P

In the meantime I discovered max(p3) >= 175 and max(p4) >= 431

@Bubbler Or I guess you can just start your first answer with # 2. p2=1 or something

caird coinheringaahing

@Bubbler Yeah, I was planning on this

Otherwise, it requires me to post two starting answers, and I don't really need to do that

Bubbler

Yeah, it also violates the second rule

caird coinheringaahing

And the first :P

Bubbler

lol yeah :P

and since 4x4 so many random starting states result in one or more free gliders

caird coinheringaahing

How many unique starting configs are there for a given n x n grid? It's bounded by \$n^2\$ below and above by \$n!n^2\$, but I can't think of a better approximation

Bubbler

23:21

How did you get the upper bound of n!n^2? I'd say more like 2^(n^2)

caird coinheringaahing

@Bubbler There's \$n^2\$ configs for each \$i = 1, 2, ..., n\$ living starting cells, with each former \$i\$ configs being counted for each \$i\$

I think

But \$2^{n^2}\$ sounds more accurate

Bubbler

2^(n^2) is simply "on or off for each of n^2 grid cells"

Bubbler

23:37

The exact number of configs w.r.t. reflection/rotation is oeis.org/A054247

and I somehow got the correct initial terms using Burnside's lemma. This is so cool

Neil

23:54

@user string literals always equal themselves because they're interned

Number Basher

lyal?

Steffan

yes

Welcome to the twenty-fifth Learn You A Lang for Great Good! Today, we'll be learning Coconut. During the event, feel free to post CMCs to practice Coconut (CoMCs), ask questions about the language, and so on.

Number Basher

nope

its 3 minutes early

Steffan

whatever