To simplify the compiler code.

# getting-started

[karelpeeters]

To simplify the compiler code.

[Florian]

I mean why do normal operators need these functions in the first place

[Florian]

Java doesnt have that

[karelpeeters]

Another way to think about it: there are no normal operators, there is only operator overloading.

[karelpeeters]

Java doesn't have operator overloading so they were forced to create special cases for primitives and strings.

[karelpeeters]

Kotlin can go the elegant route and define everything in Kotlin source code, which simplifies compiler code.

[Florian]

Ok, I think I get it

[Florian]

Thank you

[Florian]

Just one more thing I don't get

[Florian]

where are the implementation for these methods?

[Florian]

they are just declared in the file

[karelpeeters]

I can't really find it, but it's just somewhere deep in the compiler source code.

[karelpeeters]

But there's no real "implementation", it just converts to an iadd bytecode operation on the JVM or a + on JS.

[Florian]

I want to pick this up one more time

[Florian]

I understand WHY they don't have bodies, but how can they be DECLARED inside a kt file without a body

[Florian]

If the class is not abstract

[Florian]

Do those files not follow the same compiler rules?

[karelpeeters]

Okay I spent some time tracking it down in the compiler source, here it is for the JVM:
https://github.com/JetBrains/kotlin/blob/5e3a11db8e2f525dc43a722fa4d8cf7e7858a409/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/intrinsics/IrIntrinsicMethods.kt#L113

[karelpeeters]

If you follow that down it expands to a list of intrinsics, one for each primitive type.

[karelpeeters]

So no, they don't follow the normal rules.

[karelpeeters]

(IADD is literally just an integer, so that's what it actually ends up as, bytecode)

[Florian]

Oh wow, thank you for the effort!

[karelpeeters]

I wanted to know as well!

[karelpeeters]

It had been on my todo list for 3 months 😄

[karelpeeters]

Out of curiosity, why do you care so much? (not trying to be discouraging, being curious is good)

[Florian]

Because I have a Kotlin beginner tutorial running on my YouTube channel

[Florian]

So I need to know some details that I usually wouldn't care about

[karelpeeters]

Hmm I see. I void just avoid it entirely, no one asks why + in Java works either, or Object.hashcode or that kind of stuff. Same in Pyhton.

[Florian]

In one of the 1st parts we have looked into the Primitives.kt file and now we learn about functions, so I want to clarify why the functions in there don't have bodies

[Florian]

To avoid confusion

[Florian]

I don't want to explain it in detail, I just want to mention it

[Florian]

Often, these small details require most of the research time

[Florian]

And I am not a professional, I always just learn in the process

[Florian]

As you can tell from my noob questions

[karelpeeters]

I see.