The APL Orchard

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preaburn

02:23

I am using aspx files to build a website application and have an APL workspace as code behind where I reference a Class which has a page_load function. I am trying to tie to an external APL component file vis-a-vis the apl workspace. The component file is on my hard drive and I am using IIS as the server. I want to be able to read and write to the component file so I can store and update data.

The system does not let me do the file tie and I end up with a value error. I have researched the web but cannot find the obvious solution.

2 hours later…

B. Wilson

04:35

Dealing with so much Java and Groovy at work. Really tempted to casually add in Dzaima APL.

Adám

04:56

@user1782004 Hi Alexea Marie Nieves, if you want to participate here, please email [email protected]

Adám

05:09

@preaburn What error do you get from ⎕FTIE?

Who can find (or brute-force!) the 3-char solution to this?

Q: Split string on first occurrence of each character

Related. Given a printable ASCII string, split it into a list of non-empty strings with a new sub-string beginning every time a character, which has not previously been seen in the same case, occurs. Examples "mississippi" → ["m","i","ssissi","ppi"] "P P & C G" → ["P"," P ","& ","C ","G"] "A...

B. Wilson

06:02

Can't find the link for syntax here. There was a cute hack for making spoilers.

@Adám spoiler

Aiden Chow

@B.Wilson i think u do [spoiler](https://google.com "spoiler text")

Adám

@B.Wilson You don't have a link to apl.wiki/APL_Orchard on the right? it is there under Basic_formatting.

B. Wilson

@AidenChow Finally got there :P There was actually about a 5s delay until the link rendered, where it showed literally, so the last two deletions are even more spurious than the first two!

Adám

@AidenChow That makes a link rather than a spoiler.

Aiden Chow

@Adám u r supposed to hover on top of the link to see the spoiler text

Adám

06:09

yes.

ofc, that means touch devices have an accessibility problem...

B. Wilson

@Adám I do but am just dumb. Was looking for an SE link.

preaburn

I get a value error because it doesn't allow me to tie the file. I am not totally clear on the reason but it has to do with the fact that a new workspace is called everytime a page load event occurs.

Adám

@preaburn I don't follow. If you cannot tie the file, ⎕FTIE should error, but not with a value error.

5 hours later…

Richard

11:47

@Adám What time was the Quest today?

Adám

15:00 UTC, i.e. in 3 hours and 11 minutes.

2 hours later…

Silas

13:22

huh, why the time change?

Adám

Because it clashes with my schedule every Friday.

B. Wilson

14:02

@Adám BTW, the APL Quest banner announcement still seems like it's set for the old time.

Adám

14:13

@B.Wilson oops.

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Adám

@Richard @att @BrianBED user1175060 @lyxal @user287218 @user287218 @user19874054 @user19874054 @user19758417 @user19758417 @user1275760 @user1275760 consider signing up for reminders at the new time.

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LdBeth

14:31

in 30 mins

Seggan

14:52

noice the time change works better with my schedule too

Adám

Welcome to APL Quest 2018-9! Today's quest is Earlier, Later, or the Same?:

> Write an APL expression that given left and right arguments of Y M D h m s f vector timestamps returns a ¯1, 1, or 0 if the left argument represents a time that is respectively, earlier than, later than, or simultaneous with the right argument.

Richard

I wsa very proud of my solution, until you pointed me to APLchart :)

{⍺≡⍵:0 ⋄ -/⍋⍺ ⍵}

Adám

That is nice, but you can combine the guard expression and the main expression, the APL way.

Silas

oh, that makes sense - i had {×-/¯1 1⎕dt ⍺ ⍵}

Adám

You don't need to specify ¯1 — that's the default for vectors.

rabbitgrowth

15:02

I had ⊃0~⍨×⍤-

Adám

That's beautiful.

I had (>-<)⍥(1⎕DT⊂)

Seggan

@rabbitgrowth wow that ~ trick is nice

Adám

And using ⊃ to coerce a new 0 if they are all equal.

Silas

@Adám really? That seems to have domain error in tests:×-/ 1⎕dt ⍺ ⍵ caused DOMAIN ERROR with (3345 4 16 14 11 12) as left argument and (4337 2 12 17 54 7) as right argument

Seggan

~~time to rework one of my problem solving competition entries~~

Adám

15:04

Shh!

@Silas I get the same error if I have the ¯1 there.

Silas

huh, with the ¯1 says passed basic tests but not (7⍴0) as arguments

rabbitgrowth

I had ⊃0,⍨0~⍨×⍤- at first, then realized the 0,⍨ could be dropped

Adám

I'm at a loss here. I get "should have returned" with {-/1⎕dt ⍺ ⍵} but a domain error when inserting ×. How can × domain error on a number or -/ return a non-number‽

Shh!

Richard

@Adám how? You cannot distinguish between two same entries and two following up ones

Adám

{(⍺≡⍵)×-/⍋⍺ ⍵}

Richard

15:10

ah ok :)

Adám

Or train it to be ≡×{-/⍋⍺ ⍵}

Here's a fun one: ×-⍥(1000∘⊥)

Richard

@Adám how precise is this one? Will give huge numbers

Adám

Ah yes, we'll need ⎕FR←1287 for it.

Richard

I also tried to make {-/⍋⍺ ⍵} tacit.
Probably not usefull but got stuck at (-/⍒,⍥⊂)

Adám

You can do -/⍤⍒⍤,⍥⊂ but…

Anyone up for an industrial solution?

Richard

15:24

yes

Adám

{⎕USING←'System' ⋄ DateTime.Compare{⎕NEW DateTime ⍵}¨⍺⍵}

Won't work online because the Linux server has no .NET installed :-)

Seggan

dyalog apl can access .net?

Adám

Yes, it was on Microsoft's official list of .NET programming languages back when .NET was new.

Seggan

huh

Adám

Anyway, with this abomination, shall we say see you next week for 2018-10: Anagrammatically Correct?

Shh!

2 hours later…

Slimey

17:54

ive got two bqn functions:
MedianOfSortedLists ← ({𝕩{2|≠𝕨 ? ⊑𝕩⊏𝕨 ; ÷⟜2+´𝕨⊏˜𝕩-1‿0}⌊2÷˜≠𝕩}∘∧∘∾)
FirstMissingPositiveInteger ← {⌊´1+/¬𝕩∊˜1+↕≠𝕩}
both as solutions to these leetcode challenges respectively:
https://leetcode.com/problems/median-of-two-sorted-arrays/
https://leetcode.com/problems/first-missing-positive/

im new to bqn, coming from apl and im wondering about some ways to refactor these expressions.

median-function:
first off, im not proud of the algorithm in and of itself. its quite imperative by nature and requires the ? if-like statement (which i love as bqns response t…

2 hours later…

dzaima

19:31

@Slimey BQN is 0-indexed, so /𝕩 is just the thing you use for APLs ⍸⍵ with ⎕IO←0. If you require 1-indexing, you indeed just 1+ that, same thing you'd do for anything you want to make 1-indexed

an alternative way to write the second function might be {⌊´ ¬∘∊⟜𝕩⊸/ 1+↕≠𝕩}, avoiding one of the 1+es by "reusing" it

and {(+´÷≠) 𝕩⊏˜ (⌊⋈⌈) 2÷˜¯1+≠𝕩}∘∧∘∾ is one option for avoiding the branching for the median

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