do nested functions have any extra overhead? No, right?

# announcements

[Andrew Gazelka]

do nested functions have any extra overhead? No, right?

[gildor]

Yes, object will be created, same like for lambda

[Fudge]

Unless you use inline, in which case no object is created.

[Fudge]

https://stackoverflow.com/questions/44471284/when-to-use-an-inline-function-in-kotlin

[Andrew Gazelka]

these do not exist

[Fudge]

That's a different, specific case

[Fudge]

It's a local inline function

[Andrew Gazelka]

ah alright, makes sense

[Fudge]

Will your function still work not as a local function? i.e. does it use local variables?

[Andrew Gazelka]

yeah it uses local variables and I can separate it out into multiple non-local functinos but it gets messy

[Fudge]

Wait, when you say a nested function you don't mean a higher order function do you? you mean a local function?

[Andrew Gazelka]

I mean a local function

[Fudge]

In that case there are no objects created, It's just like a normal function afaik nope that is wrong

[Andrew Gazelka]

aight... well that would be nice because making functions like this is really messy https://gist.github.com/andrewgazelka/b11555496e289ced537ad281ecc95280

[Andrew Gazelka]

where the local func would require zero params

[Andrew Gazelka]

oooof

[Fudge]

It does create an object, but you shouldn't worry about performance too much

[Andrew Gazelka]

it is already a computationally expensive function, so yea I agree w/ you

[Andrew Gazelka]

it is not something which is going to be called with high frequency

[tseisel]

I guess that depends on the platform.
For the JVM, a subclass of Function will be created just like with lambdas (if the function is non capturing, a single instance of the function is reused, otherwise a new one is created each time the wrapping function is called).
For JS, nested functions are natively allowed in JavaScript, so this should not introduce more overhead than the JavaScript way to define nested functions.
As for Kotlin Native, I have no idea.

[Fudge]

I would expect it to be 30 times slower in Kotlin Native like everything else 😂

[Dico]

Yeah... K/N is indeed about a magnitude slower...