The APL Orchard

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LdBeth

06:34

I did today's using stencil

3 hours later…

Adám

09:34

A Personal History of APL (1982) on HN

5 hours later…

Stack Exchange Feeds

14:31

-1

Q: Filter a list of list based on data

I'm pretty new in APL(Dyalog), I'm trying it for the Advent of Code, so I've 1 day of experience ^^ I've this data x ← ((1 'data1') (0 'data2') (0 'data3') (1 'data4') ) x ┌─────────┬─────────┬─────────┬─────────┐ │┌─┬─────┐│┌─┬─────┐│┌─┬─────┐│┌─┬─────┐│ ││1│data1│││0│data2│││0│data3...

Ven

15:02

@LdBeth Ah, I was considering stencil too, but I need to figure out how to select the numbers first...

Adám

15:28

@YannickGuern Welcome. Feel free to introduce yourself or just lurk. We're a friendly bunch here.

rabbitgrowth

15:52

Spent way too long trying to solve today's puzzle without remembering ⌺ exists

Yannick Guern

Hello everyone ^^
My name is Yannick, I'm a french guy who love to try new concepts languages and so on
I'm actually doing the Advent of Code in Dyalog-APL, just to try ^^
As the first question ask for parsing. I'm building righ now a parser combinator to help me to beat the first day :D

Stack Exchange Feeds

Q: Apply a list of functions on the same right operand

I have 3 functions which return parse_apple 1 'bpple4578' ┌─┬─────────┐ │0│bpple4578│ └─┴─────────┘ parse_bpple 1 'bpple4578' ┌─┬────┐ │1│4578│ └─┴────┘ parse_45 1 'bpple4578' ┌─┬─────────┐ │0│bpple4578│ └─┴─────────┘ I would like to apply this list of functions on 'bpple4578' And return as so...

apl dyalog

Ven

16:35

There are easier ways to go at it :)

@xpqz I started with your solution, ended up with a better solution using ⍷, though without the parsing step of the string

LdBeth

17:05

Akanoa

Well I'm pretty happy of parser combinator
I just need to do the "map" feature
https://x.com/_Akanoa_/status/1731358784482607353?s=20

LdBeth

@Akanoa how do you parse zoneighteen and get 18?

oops I spoiled part two

@Ven Hint: a stencil window size of 1 5 to get numbers, and 3 3 to handle symbols, then 1 3 to filter our excessive numbers

Ven

@LdBeth That's just specialcasing the input, right?

there's nothing that says a number has to be 3 chars at most

LdBeth

@Ven You can used a iterative flooding of 1 3 window to get the numbers, whiteout assuming the max number length

*without

Ven

Dunno how to do that

Akanoa

17:16

LdBeth

@Ven Start with each location holds its single digit, each iteration, get the number of the two nearby cells, update as necessary, until the map stabilized. Assume max size of 3 would be much efficient than this, of course, and this can be verified easily using regexp search.

Akanoa

minor spoiler on day1 part2

@LdBeth if i've parse the term "eighteen" I can remap it as 18 integer
but as I see, the number in letters or not range between 1 to 9
'7pqrstsixteen', "sixteen" is a fake news because the last number is a 6 not 16 :p

so my parser only need to range "one", "two", .... "nine"
and "1", "2", ..., "9"

Ven

eighteen is a trap

Lucky Chouhan

17:33

Hello,

I'm new to Code Golf, what is APL Orchard, how can I prepare for it and how to find information about it?

Ven

17:53

I don't understand stencil. {⊂≢⍵}⌺ or {⊂⊃⍵}⌺ don't give me the results I expect at all

Adám

@LuckyChouhan Welcome! This chat room is the APL Orchard. See apl.wiki/APL_Orchard

@Ven What is the right operand?

Ven

My day3 advent input, split on space, mixed. 10 10≡⍴

Adám

I don't follow, neither what you are saying, nor AoC, but the right operand to ⌺ should be the windows size and optionally the movement.

Ven

oh no I mean, I called is as {⊂≢⍵}⌺1 5⊢data

that wasn't clear, sorry

Adám

Then ≢⍵ is always 1.

⍵ in the left operand is simply the current window.

Ven

18:10

I'll just 1⌷ then

Adám

Or ,

@Ven How wide is data?

Ven

⍴data is 10 10

Adám

Ah.

Ven

↑' '(≠⊆⊢)'467..114.. ...*...... ..35..633. ......#... 617*...... .....+.58. ..592..... ......755. ...$.*.... .664.598..'

Basically, this, and the task is to find the numbers there, but only when there's a non-dot symbol around it. So I was trying to figure out how to do that.

Adám

Numbers or digits?

Ven

18:24

numbers, digits would be easy

I'd stencil 3 3, check if it's a digit in the middle, and check the rest

Adám

Ah, around it like that.

So why 1 5?

Ven

@LdBeth ^

I considered doing a 3 5 stencil at first.

and 2↓¯1⌽

LdBeth

18:49

 numbermap←{
     parsn←{
         l←,⍵
         ~l[3]∊⎕D:0
         ~∨/l[2 4]∊⎕D:⍎(,⍵)[3]
         s←' .%#*$/-&+@='split l
         3=≢s:⍎2⊃s
         2=≢s:⍎s⊃⍨1+</≢¨s
         1=≢s:⍎⊃s
         0
     }
     parsn⌺1 5⊢⍵
 }

The 3=≢s:⍎2⊃s case won't happen though

Ven

OK, I got {⊂2↓¯1⌽2⌷⍵}⌺, now I need to parse either 2 or 3 digits from what's left there

LdBeth

@Adám Because the number is assumed to be at most 3 digits wide, so a window of width 5 can do the thing in one pass.

Ven

19:04

I do 2↓¯1⌽ on ⍵ and on 2⌷⍵, figure out if any of these is a symbol

Adám

@LdBeth Ah.

LdBeth

@Ven this is just {2 2⌷⍵}⌺3 3 isn't it, also you are getting a vector instead of scalar.

Ven

I guess I can actually just check ,⍵, check if there's anything's besides '.',⎕D

@LdBeth hm?

That only selects an element

LdBeth

Why would you want windows to be 3 5?

Ven

because I can see all the characters around

LdBeth

19:16

...+. ..+..
123.. 23...
..... .....

Now you have these two windows next to each other, how do you determine what number is next to the +?

...+. ..+..
.23.. 23...
..... .....

And differentiate the case above with this one?

LdBeth

19:31

Welp turns out that is quite feasible

Akanoa

Very funny ^^
@LdBeth my mapping is ready, now I need to move my parsing cursor and accumulate
but tomorrow :p
https://x.com/_Akanoa_/status/1731395652637106672?s=20

3 hours later…

Ven

23:01

I got to this, but it's too slow to run in TryAPL:

+/+/{⊂(~×/(,⍵)∊' .',⎕D)×(~(2 1⌷⍵)∊⎕D)×((2 2⌷⍵)∊⎕D)×⍎(v∊⎕D)/v←'0',2↓¯1⌽2⌷⍵}⌺3 5⊢↑' '(≠⊆⊢)input

Mh, that doesn't seem correct, unsure why :(

It works fine with the simpler example...

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