The Nineteenth Byte

Q: Geiger counter prime generation

10:01 AM

0

This challenge is quite simple to conceptualise, but likely a lot harder to execute. In this challenge, the program will have to detect the number N of its characters that have been randomly changed (at least half of the program will always remain). Then, it will have to output the Nth prime num...

New Sandboxed Posts

10:43 AM

0

A: Sandbox for Proposed Challenges

Calculate a constant from its characteristic function You are given in some language-dependent way (e.g. a lambda parameter) a characteristic function which is basically another way of saying a decision-problem function. This function will take an integer input and return true or false, or 1 or ...

flawr

12:53 PM

@MilkyWay90 Of course we have to mention that every time :D

Alion

1:18 PM

Does anyone remember Formic Functions? That was fun, and for the longest time I had an idea for a tech demo for it in the back of my mind. Now I finally found some time to turn that tech demo into reality - here it is!

@Alion :O for a long time I've also wanted to create something that could draw images, but never got to actually trying to make it. congrats on actually making it work!

Alion

Yeah, it was a major PITA to figure out the details. Ridiculously close to not being possible. I'm really angry that it can't draw the whole board, though - it falls a fifth of the board short of that...

Well, it could, but it would require a major approach overhaul, which I was simply not willing to do, since I've already sunk more time into this than I'd like to admit.

MilkyWay90

2:46 PM

@flawr In the "vjffh tivebr 3" video

Q: Can Jimmy hang on his rope?

3:42 PM

1

Yet another Jimmy challenge by his original father. See these other lovely challenges. As you all know, recently we've been seeing challenges related to Jimmy on platforms. Now, Jimmy is an acrobat as I mentioned before, and he's got other tricks up his sleeve. One of these tricks is hanging ...

code-golf string ascii-art parsing

Q: Counting generalized polyominoes

5:23 PM

1

This challenge will have you count psuedo-polyforms on the snub square tiling. I think that this sequence does not yet exist on the OEIS, so this challenge exists to compute as many terms as possible for this sequence. Definitions The snub square tiling is a semiregular tiling of the plane tha...

code-challenge sequence geometry polyomino

Anonymous

5:42 PM

@TannerSwett I disagree. 0 is a function in Haskell, but it is a built-in function, like id or (+).

5:59 PM

@Mego I'd call a built-in function a function that's pre-defined somewhere, and I doubt that Haskell has over 10^21 predefined functions for numbers. But again, that depends on what you call a builtin

you could call it an "on-demand" or a lazily calculated built-in, but in that case, any function could be called that

Anonymous

6:12 PM

@dzaima My definition of a built-in is a function/method/whatever that exists before your code starts running

@Mego Is 831459437077415617853819099875 also a built-in function?

Anonymous

Yes, as per my definition. If you wrote no code other than calling 831459437077415617853819099875 , it would still work. Therefore, it is built-in.

How about \x->x, is that a built-in function?

Anonymous

No, because you defined it yourself right there

So what's the difference between the two?

Anonymous

6:19 PM

...I just explained that

Anonymous

\x->x is defining a new, anonymous function. Anonymous functions cannot be builtins by definition, because a builtin has to have a name. You can't call it without first defining it, so it is definitively not a builtin.

@Mego to me it seems that a number exists before the code is run just as much as e.g. x=>x in JS. Both obviously aren't defined before (as there are pretty much an infinite number of both functions & numbers), but both exist when set to a variable

Well, I don't understand what you mean by "if you wrote no code other than 831459437077415617853819099875, it would still work".

Anonymous

@TannerSwett If your code consisted solely of calling the function 83, it would work, and the function would return the value 83 (which is itself).

@Mego and if my code consisted solely of calling the function ()=>83, it would work, and the function would return the value 83 - i don't see how that sets anything apart

Anonymous

6:24 PM

@dzaima You can't call that function without first defining it. ()=>83 is an anonymous function definition. It's not the name of a function. It's a function literal that can be assigned to a name.

And in any case, couldn't I just as well argue that 831459437077415617853819099875 is defining a new, anonymous function (one whose behavior is to take the given Num method dictionary, look up its fromInteger method, apply it to a particular Integer value, and return the result)?

Anonymous

No, because that's not how Haskell works. 83 has the type Int, which is equivalent to () -> Int (a zero-arg function that returns an Int). Haskell is special in that regard because there are no true value types - all value types can be treated as nullary functions which return the given value.

@Mego 83 also isn't the name of a function. If we assume that ()=>83 can be used in exactly the same contexts as just 83 (or maybe in parens or whatever, i have no idea what's the case for the haskell equivalents), then, by definition, as far as anything can be observed about the two, they work exactly identically

I'm pretty sure the type of 83 is not Int.

It's Num a => a, isn't it?

general Haskell question: so if Int → ()->Int, does that mean that ()->Int → Int?

Anonymous

6:28 PM

@dzaima There is no other syntax in Haskell. The nullary function ()=>83 in JS is just 83 in Haskell. Sure, you can tack on other stuff like toInteger 83 or id 83, but those both simplify to 83.

Anonymous

@TannerSwett Splitting hairs

And () -> Int and Int are different types with different behavior.

Anonymous

@TannerSwett No they are not

Anonymous

@dzaima Int -> () -> Int would be parsed as Int -> (() -> Int), which would simplify to Int -> Int

Okay, go to a REPL and type in 83 :: () -> Int. You'll get an error. Type 83 :: Int and it will print 83.

6:30 PM

@Mego sorry, I meant → as "can be replaced by/cast to. ._.

Anonymous

@TannerSwett My point is, the actual type doesn't matter for the purposes of this discussion.

Anonymous

@dzaima Oh, then yes.

Anyway, this discussing is making me want to go do crazy stuff with Haskell. :D

suppose in some language where the Int type can always be replaced with () => Int and vice versa, meaning that 83 can always be replaced by () => 83 and vice verse, then, by definition, 83 and () => 83 are the exact same thing. Is one of those considered a built-in? Are both? Are none?

(of course, for the purposes of the challenge, both would have to be preceded by x= but that's beside the question)

Anonymous

That would be more complicated to determine. Thankfully, that's not an issue in Haskell, because you write both the Int form and the () -> Int form as 83.

6:40 PM

You seem to think that in Haskell, 83 can have the type () -> Int without any special effort from the programmer...

Or maybe you're using "() -> Int" to mean something other than the type that that expression denotes in Haskell.

Anonymous

A nullary function that returns an Int

↑ yep, that's what I expected () -> Int to mean

@Mego the fact that you can't write () => 83 in Haskell shouldn't change that my theoretical language's builtin-ness of 83 should be equal to haskell's. If you say that 83 in haskell is a builtin, 83 in my language must also be a builtin. Does the fact that in my lang 83 ≡ ()=>83 for all intents and purposes everywhere then mean that ()=>83 is also a built-in?

Anonymous

Like I said, it would be complicated. I don't know what my answer would be. But we were originally talking about Haskell here, where it is not an issue.

() -> Int is a unary function that takes a thunk of type () and returns a thunk of type Int.

(Or maybe it returns a value of type Int rather than a thunk. I don't know, but I don't think it matters.)

hmm, google doesn't seem to say that "programming language philosophy" is a thing

6:50 PM

Say, I really need to come up with some more esolangs.

I wonder if I can come up with one based on aviation. 🤔

8:04 PM

@NewMainPosts decided to see how would a Jelly answer port of my APL look for that, and wrote my first Jelly code that actually does something: Ṗn⁶§ċ3

Erik the Outgolfer

@dzaima this actually ties Jonathan Allan's approach, Ṗ<”|ṀẠ

flawr

@Mego @TannerSwett @dzaima there is chat.stackexchange.com/rooms/66515/of-monads-and-men and you're invited to join:)