crystal-lang/crystal

The Crystal programming language | http://crystal-lang.org | Fund Crystal's development: http://is.gd/X7PRtI | Docs: http://crystal-lang.org/docs/ | API: http://crystal-lang.org/api/

azurelmao

@azurelmao

So in order to skip past indexes I first have to fill the array with some value?

George Dietrich

@Blacksmoke16

there's another overload that allows you to initialize each index to some value if you want

azurelmao

@azurelmao

Yeah ik, I had just hoped there would be a more convienent way to do it

George Dietrich

@Blacksmoke16

more convenient how?

or backing up, what end result are you wanting?

azurelmao

@azurelmao

It's just that I have a class which adds itself to a class var on init

def initialize(@id)
    if id > 0
      @@item_list.insert(@id, self)
    end
  end

so now I have to check whether the id is 0

in order to fill the array

George Dietrich

@Blacksmoke16

are they instantiated in order? i.e. is it possible the first instance has an @id of 10 and the next 1 or is it always going to go in order?

0, 1, 3, ...

0, 1, 2, ...*

azurelmao

@azurelmao

they won't be in order

George Dietrich

@Blacksmoke16

Hash(Int32, self).new then?

azurelmao

@azurelmao

Oh, I haven't thought of that

I'll try it

George Dietrich

@Blacksmoke16

seems like a more reasonable data model if you just want to store objects with a numerical key

azurelmao

@azurelmao

btw, this is unrelated to my previous question I'm just curious, but is there a literal for object instantiation? Something like:

foo = Foo{id: 1}

Which would bypass the initialize method and let you assign the properties by hand

George Dietrich

@Blacksmoke16

azurelmao

@azurelmao

I see

George Dietrich

@Blacksmoke16

unless you make everything nilable and do something like:

foo = Foo.new
foo.id = 1
...

but ofc, having a proper constructor is usually the better way

i.e. Foo.new 1 or Foo.new id: 1

azurelmao

@azurelmao

I usually avoid Nilable types, because of the trouble they cause

Anyways, thank you for helping me!

George Dietrich

@Blacksmoke16

actually, not exactly what you want, but you could look into https://crystal-lang.org/reference/1.6/syntax_and_semantics/literals/hash.html#hash-like-type-literal

From IRC (bridge bot)

@FromIRC

<SamantazFox> For anyone interested: I've been doing my Advent of Code in Crystal this year ^^ https://github.com/SamantazFox/AoC-2022

From IRC (bridge bot)

@FromIRC

<riza> SamantazFox: there are a bunch of us, the Discord server has an aoc channel. But I'm over here at github.com/robacarp/advent_of_code/

<riza> a couple more links from the discord https://github.com/hovsater/aoc-crystal

<riza> https://git.sr.ht/~refi64/AoC-2022

<riza> https://github.com/Daegalus/adventofcode22

<riza> there are probably many others

<riza> oh we have a leaderboard too....uuuummm

<riza> https://adventofcode.com/2022/leaderboard/private/view/659296

re:fi.64 🏳️‍🌈

@refi64:linuxcafe.chat

[m]

Note that mine is not actually in Crystal 😅

From IRC (bridge bot)

@FromIRC

<riza> oh whoops

<riza> i like that they're on sr.ht

<riza> i keep meaning to set up a gittea or something but ...

re:fi.64 🏳️‍🌈

@refi64:linuxcafe.chat

[m]

sr.ht is definitely pretty nice

Hasnep

@hasnep:matrix.org

[m]

Hi, does anyone know if there's a shard or some stdlib functionality to replicate Python's pydantic library? i.e. parsing JSON to a class

George Dietrich

@Blacksmoke16

https://crystal-lang.org/api/JSON/Serializable.html

Hasnep

@hasnep:matrix.org

[m]

Perfect, thanks!

Maurizio De Santis

@mdesantis

hello! I'm confused by type aliases. I can't see why this works:

alias DeviceName = String
alias DeviceFile = Int32
alias DeviceDir = Hash(DeviceName, DeviceFile | DeviceDir)

pp Hash(DeviceName, DeviceDir).new
pp Hash(DeviceName, DeviceFile).new
#=> {}
#=> {}

but this doesn't:

alias DeviceName = String
alias DeviceFile = Int32
alias DeviceDir = Hash(DeviceName, DeviceFile | DeviceDir)

pp Hash(DeviceName, DeviceDir).new
pp Hash(DeviceName, DeviceFile).new
pp DeviceDir.new
#=>  21 | pp DeviceDir.new
#=>                    ^--
#=> Error: undefined method 'new' for DeviceDir.class

if DeviceDir is an alias of Hash(DeviceName, DeviceFile | DeviceDir), why can't I call .new on it?

ShalokShalom

@ShalokShalom

hi there

is there somebody who has tried to run Crystal on the GraalVM?

It has support

George Dietrich

@Blacksmoke16

@mdesantis crystal-lang/crystal#9752

related: crystal-lang/crystal#5155

recursive aliases are usually frowned upon, so might want to go to plan b

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