Conversation

Notices

1. Embed this notice
   Helge Heß (helge@mastodon.social)'s status on Friday, 20-Sep-2024 07:19:47 JST Helge Heß

   • Paul Cantrell

   @inthehands I think the bigger issue/question is that properties are supposed to be idempotent. That's what makes it a property to me.

   • Embed this notice
     Paul Cantrell (inthehands@hachyderm.io)'s status on Friday, 20-Sep-2024 07:19:46 JST Paul Cantrell

     in reply to

     @helge
     Wow, that’s an interpretation of the word that’s new to me!

   • Embed this notice
     Helge Heß (helge@mastodon.social)'s status on Friday, 20-Sep-2024 07:28:51 JST Helge Heß

     in reply to

     • Paul Cantrell

     @inthehands Interesting. A property to me should have no meaningful side effects. I've seen people doing KVC properties and wondering when they run into issues because a property setter also set like 10 other unrelated things.

   • Embed this notice
     Paul Cantrell (inthehands@hachyderm.io)'s status on Friday, 20-Sep-2024 07:28:51 JST Paul Cantrell

     in reply to

     @helge
     Does this mean that “to change a property” or “set a property” is ill-defined in your lexicon?

   • Embed this notice
     Helge Heß (helge@mastodon.social)'s status on Friday, 20-Sep-2024 07:36:18 JST Helge Heß

     in reply to

     • Paul Cantrell

     @inthehands No, the operation should just be idempotent, i.e. have no side effects. Like this:
     ```
     final class Mehr {
     var _x = 0
     var y = 0

     var x: Int {
     set {
     _x = newValue
     y += 1
     }
     get { _x }
     }
     }
     ```
     I wouldn't consider `x` a "property" here because calling it 10 times will have side effects unrelated to it. This would be fine:
     ```
     final class Meer {
     var _x = 0

     var x: Int {
     set { _x = newValue * 2 }
     get { _x / 2 }
     }
     }
     ```

   • Embed this notice
     Paul Cantrell (inthehands@hachyderm.io)'s status on Friday, 20-Sep-2024 07:36:18 JST Paul Cantrell

     in reply to

     @helge
     Ah, no side effects •other than the property state itself• — yes, agreed!

   • Embed this notice
     Helge Heß (helge@mastodon.social)'s status on Friday, 20-Sep-2024 07:39:49 JST Helge Heß

     in reply to

     • Paul Cantrell

     @inthehands Essentially this:
     ```
     thing.a = 5
     thing.a = 5
     thing.a = 5
     ```
     should modify nothing but `a`. But those could also be composed values, the key thing is that you can assign as often as you want w/o side effects.
     That's what makes a property to me, not whether it is computed or stored.

   • Embed this notice
     Paul Cantrell (inthehands@hachyderm.io)'s status on Friday, 20-Sep-2024 07:39:49 JST Paul Cantrell

     in reply to

     @helge
     Yeah, then in that case, I think our personal definitions are very close.