Kotlin is fatter, compiler is slower, code completion is slow as hell on large projects, but other than building small applications - there's really no reason to not use kotlin except for the fact that you need to actually learn the language or else you're going to end up with very very slow codebase where opening a file and waiting for syntax highlighting takes 2-3 seconds and typing autocomplete is just painfully slow.
"fatter, compiler is slower, code completion is slow as hell" - if that's all you want out of your programming language, then Java is probably a good choice for you.
For others that value the things that Kotlin brings over Java (even modern Java), and for the ways in which it delivers a simpler experience than Scala - I think it's a pragmatic and sensible decision.
I wonder if that confusion is due to the fact that you haven't yet wrapped your head around the fact that extension functions are "just" syntactic sugar for static functions. The implicit "this" becomes the the first parameter of the static function and function parameters can be null. Now you might ask "why not use static (/first class) functions then? Because those "feel" like less ideomatic to use then extension functions or methods that are defined on the object (hirachy) itself.
But understanding why the extension type can be nullable is not the same is using it on nullable types. I restrict my extension functions to non-nullable types most of the time as well. The best exception to this preference -just to see where it makes sense- is the build-in function [toString](https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/to-stri...), since you want it to return "null" if you invoke it on null.
val a: SomeType? = null
// I’m forced to null check here
if (a != null) {
a.someMethodOnIt()
}
// But I don’t have to null check here
a.someExtensionFn()
Kotlin is fatter, compiler is slower, code completion is slow as hell on large projects, but other than building small applications - there's really no reason to not use kotlin except for the fact that you need to actually learn the language or else you're going to end up with very very slow codebase where opening a file and waiting for syntax highlighting takes 2-3 seconds and typing autocomplete is just painfully slow.
"fatter, compiler is slower, code completion is slow as hell" - if that's all you want out of your programming language, then Java is probably a good choice for you.
For others that value the things that Kotlin brings over Java (even modern Java), and for the ways in which it delivers a simpler experience than Scala - I think it's a pragmatic and sensible decision.
I do like the lack of extension functions. I find them confusing, especially when you can use them on things that are null.
I wonder if that confusion is due to the fact that you haven't yet wrapped your head around the fact that extension functions are "just" syntactic sugar for static functions. The implicit "this" becomes the the first parameter of the static function and function parameters can be null. Now you might ask "why not use static (/first class) functions then? Because those "feel" like less ideomatic to use then extension functions or methods that are defined on the object (hirachy) itself. But understanding why the extension type can be nullable is not the same is using it on nullable types. I restrict my extension functions to non-nullable types most of the time as well. The best exception to this preference -just to see where it makes sense- is the build-in function [toString](https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/to-stri...), since you want it to return "null" if you invoke it on null.
I have wrapped my head around it. I think it's confusing to the reader and creates awkward semantics.
Yeah, extension functions are one of those features that went from 'oh, this is nice' to "this is so overused it's counterproductive".
It makes reading a lot of Kotlin source quite terrible.
Lately they've been shoveling a lot of similar magical "code comes from somewhere" features into a language, slowly giving it a C++ clutter type feel.
What I mean by that is this:
It’s weird.