07:04 <quazimodo> holler

07:05 <quazimodo> i have a question about crystal's type system; can i say "argument x is anything that implements a method that takes an arg of type whatever, and returns some other type

07:05 <quazimodo> basically without referencing a class or an interface, i jst want to tell it any instance/object with a method 'foo' that takes some y and returns some z

07:06 <quazimodo> this is a common approach in typescript, and i know crystal isn't typescript, but i'm having trouble wrapping my head around how crystal does structural types

07:07 <quazimodo> or do you define an abstract class and then let crystal figure out if some other class 'fits' the definition of that abstract class?

08:53 <jhass[m]> As for method arguments, just don't put any type restriction at all. You'll get a compile time error when something is passed that doesn't respond to the methods you call inside. This is called duck typing

08:54 <jhass[m]> As for instance variables, unfortunately doesn't exist. Your two options are to define a union for all types you wanna allow (potentially as an alias) or to define a module with that method (potentially abstract) and include it in all types you wanna pass (potentially by reopening them if they're not yours)

09:50 <quazimodo> jhass[m]: i disconnected

09:50 <quazimodo> did you say anything befor ethat?

09:50 <quazimodo> ah nvm i found the gitter

14:56 <FromGitter> <moe:busyloop.net> once you learn the crystal way you'll realize how awfully broken the typescript approach is

14:57 <FromGitter> <moe:busyloop.net> (in their defense, shoehorning types onto an untyped language - and the language being javascript of all things - gotta cut them some slack for even trying...)

18:52 <_dave> is there a way to have module-level methods defined in one file applied to files required further down the chain? or should i just have those methods put in another submodule and then require it in the files i'll use those in?

20:04 <FromGitter> <Blacksmoke16> 🤔

20:06 <FromGitter> <Blacksmoke16> in order to use methods in a module you have to include the module somewhere, or `extend self` which will make them act as class methods using the module's name as the type

20:06 <FromGitter> <Blacksmoke16> just defining a module with methods in it and requiring that file in other files isnt enough

20:07 <FromGitter> <Blacksmoke16> id like to know more of what you're wanting to do before i give more suggestions

21:02 <_dave> @Blacksmoke16: basically i have a module for my program, let's call it `Game`. in it, i have a die roller method `roll`. i was having problems trying to use that method in other classes *within the same module*, errored as "missing".

21:03 <_dave> i can tell that means that it's not namespacing the way i'm looking.

21:58 <FromGitter> <moe:busyloop.net> best put some sample code on https://carc.in/#/cr

22:01 <FromGitter> <Blacksmoke16> modules are class scope, so you prob need to do like `def self.roll` then could call it anywhere as `Game.roll` if that helps?

22:01 <FromGitter> <Blacksmoke16> but yea, an example would be 💯

22:05 <FromGitter> <Blacksmoke16> to clarify w/o `self.` prefix, you'd have to import the module its defined in somewhere in order to actually use it

22:20 <FromGitter> <may> Is there a way to determine if there is data in STDIN at runtime? I'm writing a script that may or may not have data at runtime, but I don't want it to hang on a `gets` call while waiting for input since there isn't going to be any. ⏎ ⏎ I've tried `STDIN.nil? STDIN.peek` and similar but haven't been able to figure it out.

22:35 <FromGitter> <moe:busyloop.net> it's a bad idea. you could in theory use select() to check if there's data - but that fails if the writer hasn't already written

22:35 <FromGitter> <Blacksmoke16> i cant really think of a good way to do it, other than hacking in something with `select` to allow `STDIN` to block in a diff fiber:

22:35 <FromGitter> <Blacksmoke16> ```code paste, see link``` ⏎ ⏎ something like this [https://gitter.im/crystal-lang/crystal?at=63c08b4e51d2482e9105b6a7]

22:36 <FromGitter> <moe:busyloop.net> you can also use #isatty to see if stdin is connected to a tty, but that has problems of its own

22:37 <FromGitter> <Blacksmoke16> or maybe this is something you could do with `STDIN.raw`

22:37 <FromGitter> <moe:busyloop.net> @Blacksmoke16: but when do you exit? :)

22:38 <FromGitter> <moe:busyloop.net> it may work for long-running process, but that would be quite a weird contraption. could maybe make sense if it's a log forwarder or such

22:59 <FromGitter> <Blacksmoke16> *never*

23:19 <FromGitter> <abduct> hello all. i am running into a weird behavior and i am curious if anyone has any input. https://carc.in/#/r/edw1

23:20 <FromGitter> <abduct> im of the understanding that tan-1(0/ANYTHING) should always be 0, but crystal returns PI or 180 degrees for negative divisions

23:27 <FromGitter> <may> Thank you all for the thoughts, I appreciate it!

23:28 <FromGitter> <Blacksmoke16> @abduct you get the same output in Ruby so prob safe to say its expected output?

23:30 <FromGitter> <Blacksmoke16> also realize you're printing both the `atan2` value and then the rest. so the 2nd values are ultimately what you want yea?

23:32 <FromGitter> <Blacksmoke16> same output in PHP

23:33 <FromGitter> <Blacksmoke16> also https://www.wolframalpha.com/input?i=atan2%280%2C-14.8%29*%28180%2Fpi%29