Hi all, I'm learning Kotlin through koans and I saw this code (not my, part of the exercise). The code is here: https://pastebin.com/A7vwUqiy I don't understand why the extension method set (at the bottom of the snippet) was written as an extension method? why not just write it as a normal method inside the Tag class? Is this just more idiomatic in Kotlin, or do you achieve something here that cannot be achieved with normal methods?

One could argue that

set

is part of the DSL and if you put it in a different package then you have isolated the DSL related methods from the class itself

Ok, thanks for info 👍 So it doesn't make sanse to have it like this in the same file, but rather having it totally separated from the class itslef

Sometimes it does. Check out @elizarov's article about extension-oriented design: https://medium.com/@elizarov/extension-oriented-design-13f4f27deaee

Thanks, will do