The Nineteenth Byte

user

00:50

Documentation for (Pharo) Smalltalk is so absolutely terrible

I'm trying to read from a file, and the example in the File class involves calling some methods directly on a File object, but those methods are actually *class-side*/static and take the id of the file as an input, but I have no idea where to get those ids from automatically :(

OldSandboxPosts

Sandbox posts last active a week ago: Convert codepoint to UTF-9, Implement Unix Timestamp to Daytime

Wezl

01:27

wow I never knew, apparently javascript was released the same year as java

history teacher says national history day projects must be about 20+-year-old topics, so I can't do a project on Ultrarisky

Redwolf Programs

Aw :(

Truly a lot of historical events in its 8h of existence

Wezl

I could finally use primary sources

last year (two years ago because 2020 never happened) I researched wikipedia because teachers keep specifically telling us not to use wikipedia

but I can use Ultrarisky as evidence of javascript's capabilities

if it's open-sourced, naturally

lyxal

@Wezl so do it on APL

because APL is cool

5

Wezl

01:44

the theme is Debate and Diplomacy, so I can make a presentation about index origin and stuff

DLosc

@user Weird coincidence: I just came here to say I absolutely love the intro paragraph of Esolangs's page on Lisp!

Adám

@Wezl I'll help if you need it.

Wezl

you can write the diplomacy section :P

Adám

Relevant

Wezl

perhaps I shouldn't research a topic that I am so biased(/knowledgeable :P) about

Redwolf Programs

01:54

Researching a topic you're already biased and knowledgeable about just means an easy A :p

Adám

Why not? Then you can add an opinion section.

Redwolf Programs

(At least, according to my friend who's turned in the same english essay for the last four years)

DLosc

02:14

CMQ: I have four list operations: head returns the first element of a list; tail returns all elements but the first; last returns the last element. What should I name the operation that returns all elements but the last?

Adám

@DLosc neck

user

@DLosc The entire article is a treat

Bubbler

@DLosc Haskell calls it init. It agrees with all other three names too

DLosc

@Bubbler Ah, perfect!

Adám

@DLosc However, I disagree with your current naming. Should be head for first, behead for all-but-first, tail for last, and curtail for all-but-last.

DLosc

02:18

@Adám I've definitely considered that.

Bubbler

^^ It is J's naming if anyone's wondering

Adám

:-)

Bubbler

Factor: first, rest, last, but-last

Adám

So inconsistent. Why isn't it but-first?

Bubbler

head and tail are reserved for what APL calls take and drop

@Adám Well, I didn't name it :P

Adám

02:21

Gotta love it when the implementation in APL is shorter than the shortest meaningful names: 1∘↑ and 1∘↓ and ¯1∘↑ and ¯1∘↓

user

@Adám Makes sense, but I’d feel a bit queasy writing that in my code

Perhaps body instead of beheD?

Bubbler

Obligatory reference to no A, just CAPS LOCK

user

@DLosc dropRight 1

Adám

@user But the idea is that the remainder after removing X is prefixX.

DLosc

For some reason, I thought I got head and tail from some Lisp dialect, but neither Common Lisp nor Scheme appear to use those names (preferring to stick with the traditional but today meaningless car and cdr).

lyxal

02:26

@DLosc sans-tail

Bubbler

Ocaml has shorter hd and tl, but no equivalent for the other two

Adám

How about a and bc and z and xy?

user

@DLosc Where did Haskell and Scala get head, tail, last, and init from?

DLosc

In Brachylog, it's head, behead, tail, and... knife. Possibly a Three Blind Mice reference, more likely an attempt at shoehorning a mnemonic around the command k

Adám

init really sounds like something entirely different.

user

02:29

head and tail in linux refers to the first few and last few elems iirc

@Adám initial elems (but yeah, sounds like pythons init)

Bubbler

For whatever naming, you eventually get used to it anyway

assuming you don't give up entirely

DLosc

@user Not sure. I think in my CS classes the terms head and tail were always used in that sense when talking about linked lists, though.

Adám

And all these names are so ambiguous. You can't tell from the names head and init what is what.

same with tail vs last.

DLosc

Maybe it should be first, unfirst, last, unlast

Bubbler

In strictly typed langs, you're supposed to (at least partially) figure out what it does by looking at its type

DLosc

02:32

Or non instead of un, since un sort of implies an action

Bubbler

head and init have different type ([a] -> a vs [a] -> [a]) so Haskellers don't have problem differentiating the two

Adám

How about first dropfirst last droplast?

@Bubbler Oh, so they aren't 1∘↑ and ¯1∘↑

Bubbler

head is more like ⊣/ and init is like ¯1∘↓

Adám

I'd say head is ⊃ and tail is ⊃⌽

Bubbler

@Adám s/tail/last

tail is 1∘↓

Adám

02:36

Oof, well, proves my point :-)

Bubbler

Learning names is hard, really

Adám

Learning symbols is much easier.

DLosc

Ehh... the experience varies from person to person, I'd say

Bubbler

@Adám It... doesn't exactly help when you have specific names attached to each symbol (though it would help with building intuition as you go)

Adám

Who has specific names attached to symbols?

Bubbler

02:39

... my English isn't perfect

Adám

?

Bubbler

I mean like, ∊ has at least three names attached to it

epsilon (the symbol), enlist, member-of

Adám

That's the symbol, the monadic function, and the dyadic function. Sure, those are the official names – I think.

But monadic ∊ is "flatten" and dyadic ∊ is "in" or "element of" too.

- is dash/hyphen/bar, negate/negative/invert/opposite-sign/minus, minus/subtract/lessen-by…

Symbols are clear and unambiguous.

Bubbler

But you need to eventually know the official names to be effective, at least IMO

Adám

Huh. Why?

DLosc

02:52

I tend to want to pronounce stuff in my head (or out loud, if there's no one around to look at me funny).

Bubbler

Or it's just my bias from me depending on the official docs too much (and it isn't too helpful when you don't know the official name)

Adám

Oh wow. I don't associate the APL symbols with words until I actively try to.

Bubbler

Also yeah, verbal communication stuff

emanresu A

@pxeger What's match, that doesn't work...

Unrelated String

i forget if it's a 3.10 or a 3.11 thing

emanresu A

03:05

Oh I need to update Python

When you run python3 -v instead of python3 -V

Seriously...

Everything else uses -v...

@pxeger Oh well, you still missed a tab and now it's mostly unreachable

lyxal

Fun thought for the day: putting bread into a toaster makes it toast. Does that mean putting toast into a breader makes it bread?

9

Bubbler

03:29

Any last-minute feedback on river crossing puzzle thingy?

emanresu A

Looks good

Niko

03:44

Sounds good

New Posts

0

Q: Crossing a river with weird animals

Background One kind of river-crossing problems involves two kinds of animals. One such problem reads like this: (all wordings, including animal species, are arbitrary) A farmer has to cross a river with three chickens and three dogs. There's a boat which can only fit the farmer and at most two a...

Huỳnh Trần Khanh

03:59

when i see a bubbler post, i upvote

bubbler is such a god

Bubbler

Thanks for upvote, but lol no I'm not a god :)

lyxal

duh

you're Bubbler

Bubbler

^

Redwolf Programs

04:17

I think I might have found an interesting property of hamming codes

emanresu A

What?

Redwolf Programs

You can make a 2d grid, with hamming codes on both axes, and they'll make sense with each other

That probably doesn't make sense

emanresu A

Hm

I have an idea of what you're saying but it's probably wrong

Redwolf Programs

Here:

lyxal

Redwolf Programs

04:18

This is a bunch of 15,11 hamming codes, and they overlap

Everything green (the color is hard to see) is the data

PyGamer0

@RedwolfPrograms didnt 3b1b make 2 videos on hamming codes?

Redwolf Programs

The gray and blue are the redundant bits, and they correspond with the parities of both the rows and the columns

It's quite cool

@PyGamer0 Yep, that's how I learned about them :p

This could actually be a pretty good error correction system, since you could lose a burst of up to like 16 bits in a row and repair it

PyGamer0

@RedwolfPrograms didnt he also display them in the grid form?

Redwolf Programs

This is different

PyGamer0

how?

Redwolf Programs

04:20

These are 22 (or 32, depending on how you count) hamming codes

They're arranged in rows and columns

E.g., row 7 would be a hamming code all on its own

And you could fit it into the 4x4 grid 3b1b used as an example

With this system, if a bit is flipped, you could fix it either by row or by column. That means you can fix long stripes of missing data by approaching them from the opposite side

It comes at a cost though. This one fits 121 bits of data in a 256 bit block, but it'd be more efficient if you scaled it up.

It feels extremely elegant though

Sandbox Posts

0

A: Sandbox for Proposed Challenges

Build the stove controller (physically) atomic-code-golf logic-gates Challenge Build the Wheat Wizard's stove using 2-input NAND gates. The solution with the fewest NAND gates wins. Externally, it works in the following way: (the first line is added from the original spec for physical output) It...

PyGamer0

04:37

CMQ: I have plans to be able to do: Þ∑÷L for average, instead of ≡∑⍨L÷, also it depends on the arity of the 3 operators after Þ, so if i have Þ∑L÷, it will be: ÷L∑.

^ for stack based

^ is it a good idea??

Redwolf Programs

I wish my stove was interesting. For controls all it has is a regular old lever-and-flamethrower arrangement where you use the lever to put the transmission into the right gear, then trigger the flamethrower, lighting the gas in the combustion engine and cooking the food.

2

PyGamer0

levelup.gitconnected.com/…

^ what is that dumb list

^ they dont even mention haskell / apl

Redwolf Programs

TBF those are not particularly practical to learn as a regular old dev

Bubbler

> We often meet .NET, and Java experts. But, we rarely see programmers who master multiple languages.

It's very opposite here

PyGamer0

@Bubbler lol

Redwolf Programs

04:39

@RedwolfPrograms Almost nobody uses them for actual business stuff

I do sort of disagree with the list though. C/C++ don't seem like they're exactly gaining in usage

And bash seems more like the sort of thing you can get away with picking up little bits of here and there

PyGamer0

then s/c\+\+/rust

and then c != c++

Redwolf Programs

Yeah, C and Rust seem like the two lower level languages to learn

PyGamer0

why c??

its much harder

Redwolf Programs

C++ just seems like the awkward middle child between C and Java

If you want something low level without many distractions as a learning experience, C is pretty nice

PyGamer0

@RedwolfPrograms but in fact java is a kid of c++ , and why are we talking about families

Redwolf Programs

04:45

I'm not using the metaphor as in their siblings in what they were based off of, just C++ seems like it takes the middle ground between C and Java and I think it has some of the worst stuff from both (and adds in its own unique quirks)

Bubbler

Learning C is meaningful for 1) the memory model and 2) the inner workings of basic data structures found in the stdlib of other languages

C++ is just frick

Unrelated String

yeah

Redwolf Programs

Multiplying cout by 2 ** x should output x

For consistency's sake

Unrelated String

true

@PyGamer0 why would they choose go over haskell or apl

PyGamer0

@UnrelatedString idk

Unrelated String

04:59

it's like go is the most "different" thing the author has ever interacted with

which is just
sad

lyxal

@NewPosts I've tried for half an hour to solve this using codex (GPT-3) but with no luck

There's been some real interesting solutions, including creating a DFS helper function inside the submission

but none have worked

and now I've accidentally lost the prompt I was working with

so now I can't keep trying what I had

Bubbler

inb4 Jelly solution: construct all possible paths and check if any of them is covered by the input

AviFS

05:16

@cairdcoinheringaahing I'm sure you've already addressed your intentions on running in a much more grown up way, but... don't you dare not run for election, caird!

Oh wait, now I realize the election is for SO. I'm the worst, smh

lyxal

Lol

AviFS

(To clarify, I didn't understand anything. I thought we were electing one more person, and caird was the only honorary mod TNB guy who didn't win. But I didn't see his name in the running, so I feared the worst. Does that make any sense?!)

PyGamer0

lol

AviFS

But but but, do you get it though?

I just had a notification for an election (which I figured was CGCC adding an additional moderator), so I clicked it and didn't see caird. That's how you know the world is ending.

hyper-neutrino

05:36

lol

PyGamer0

CMQ: I have plans to be able to do: Þ∑÷L for average, instead of ≡∑⍨L÷, also it depends on the arity of the 3 operators after Þ, so if i have Þ∑L÷, it will be: ÷L∑. Is this a good idea for dinoux?

hyper-neutrino

i mean if there were a CGCC election

you would've been hearing about it for a while now

with discussions on who's running, candidates, the election room generated for every election, etc, and it'd have been pinned like 8 times here

emanresu A

Bubbler

Protip: Before reacting to anything in your inbox, check the site icon first

hyper-neutrino

^ lol

also there's like no way caird wouldn't run. at least without like 17 people asking why here

Bubbler

05:44

I think moderator elections are announced to all users, ignoring whether they're actual members of that specific site or not

lyxal

@PyGamer0 just parallel apply sum and length then divide

PyGamer0

@lyxal ?

hyper-neutrino

well all eligible voters i think

definitely not every user otherwise everyone would be getting spammed all the time

lyxal

@PyGamer0 ₌∑L/ but dinoux

emanresu A

@hyper-neutrino Agreed

PyGamer0

05:47

@lyxal wdyM

lyxal

@PyGamer0 Try it Online!

PyGamer0

@lyxal idk

lyxal

Para apply seems more useful than tacit chaining for stack based

PyGamer0

@lyxal docs?

lyxal

@PyGamer0 apply sum and length using the same stack

PyGamer0

05:50

so parallel apply applies 2 functions on one element?

lyxal

3 4₌+- pushes 7 and -1

@PyGamer0 almost

3 4 ₌+d pushes 7 and 8

emanresu A

Runs both, one on a duplicated copy of the stack, then push the top of the duplicated stack to the main stack

PyGamer0

@emanresuA ?

emanresu A

Look at the transpiled python

Bubbler

I have an idea... Factor's "stack effect checker" concept hasn't been in any stack-based esolang I think

lyxal

05:54

@PyGamer0 It's as if it created two different processes with the same stack, ran both processes at once, and merged their results into the main stack in order of process creation

PyGamer0

@lyxal oh

Bubbler

It basically computes how many items a function consumes from / outputs on the stack, so it can be seen as different "arity" of functions

which in turn allows a combinator to act differently based on that arity

emanresu A

So Factor's fixed-arity?

Bubbler

Mostly for named functions, though there are certain escape hatches

PyGamer0

i dont understand factor's combinators

Bubbler

06:07

:/

PyGamer0

:\

it doesnt say how it works

@lyxal is hardcoded arrays (this) counted as structures?

Bubbler

@PyGamer0 Summary articles are a bit unkind, but specific words (bi, 2bi, bi*, 2bi*, bi@, 2bi@) have a more concrete description

lyxal

@PyGamer0 a list is considered a structure internally

@Adám when curating the snippets for APLCart, how did you choose what problems/subtasks/idioms to include?

Bubbler

There were a few existing compilation of APL snippets

like FinnAPL idioms (warning: extremely slow to load... sometimes)

PyGamer0

06:26

@Bubbler what it loaded very quickly for me

New Posts

0

Q: Magic square for odd numbers challenge

Challenge Create a magic square generator for odd numbers with python 3. The user should enter an odd number(n) and the program should output a magic square with dimensions n x n. You cannot use any imported modules. Test cases The user can input any character. Only the program should decline the...

matrix python

emanresu A

> It should be very efficient

Definitely a homework question

Bubbler

Well, it can be done in O(n^2) (linear in the output size) because a simple cell-filling procedure will do it

lyxal

@NewPosts so tempted to answer with what codex generated

Bubbler

06:42

And I'm again tempted to argue "CGCC newbies are required to read all the FAQs and related meta posts, and lurk for a month before participating"

5

Huỳnh Trần Khanh

lurking is an underrated skill

Bubbler

Also we already have "efficient" python code that does odd magic square

Dupe?

Huỳnh Trần Khanh

07:13

lol

Newly Featured Posts

07:36

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Q: Surround a string with hashes

I've already made this in Python, but it seems that it could be shortened a lot: txt = input("Type something.. ") c = "#" b = " " print(c * (len(txt) + 4)) print(c, b * len(txt), c) print(c, txt, c) print(c, b * len(txt), c) print(c * (len(txt) + 4)) So if the user types: Hello World The pr...

code-golf string

caird coinheringaahing

07:47

@AviFS After much consideration, I've decided not to run in the SO mod election, as I think Ryan M would be a much better candidate than I would :P

Although at least I know I'd have support if/when I do run for mod here :P

PyGamer0

looks like haskell

Bubbler

Looks more like typed Factor to me

PyGamer0

08:02

f(x,y) = h(x)(y)

^ thats currying?

Bubbler

Yes

h is the curried function, f is uncurried one

PyGamer0

how is it useful??

@lyxal does vyxal have dip?

Unrelated String

@PyGamer0 from which perspective

PyGamer0

@UnrelatedString stack based

Unrelated String

...i may or may not have been thinking on and off about making a stack language that leverages currying extensively and failed to actually think of something

emanresu A

08:08

What is quot in that contextt?

PyGamer0

@emanresuA a function

Unrelated String

if it's like a builtin that curries things that aren't by default curried then it could be helpful for partial application and the like

emanresu A

In that case, $†$

Bubbler

@PyGamer0 Then forget currying and just think of it as partial application

PyGamer0

@emanresuA for dip?

emanresu A

08:10

Ye - swap, call, swap

PyGamer0

but what if the function called pops more than one value

Bubbler

But the point of dip is that the called function can take more than one argument

ninjad

1 2 3 [ + ] dip -> 3 3

Unrelated String

otherwise you could just flank with swaps

emanresu A

Oh

Bubbler

it's more like you move the top to a hidden stack, call it, and then move back

emanresu A

08:12

£†¥ then, assuming no register use

Or →x†←x with variables

Or even →†← using the ghost variable

PyGamer0

what about keep

looks like dup;store;call;recall

Bubbler

Usefulness of partial application: { 1 2 } 3 [ [a,b] ] curry map -> { { 1 2 3 } { 2 3 } } (things wrapped in curly braces make a list)

@PyGamer0 you got it right

PyGamer0

in factor: bi / tri just are like parallel applies?

Bubbler

yes, apply 2 or 3 functions to a single data

PyGamer0