I'm curious, why was `-Xir-generate-inline-anonymo...

# javascript

[Edoardo Luppi]

I'm curious, why was -Xir-generate-inline-anonymous-functions introduced? I can't find resources on it on the internet.

[Artem Kobzar]

From the commit that introduced this flag:

Previously we always generated factories for contextful lambdas like this:

fun foo(a: Int) = { a }

function foo(a_38) {
  return foo$lambda(a_38);
}

// factory!
function foo$lambda($a) {
  return function () {
    return $a;
  };
}

After this patch, the generated code for foo is more concise:

function foo(a) {
  return function() { return a; };
}

[turansky]

Is it available in Kotlin 1.9.23?

[Artem Kobzar]

Yes, it should be available since 1.9.20

[turansky]

Is there -Xir-generate-js-arrow-functions-please option? 🙂

[Edoardo Luppi]

Thank you!

[Edoardo Luppi]

Btw, it seems it's not enabled by default. I wonder why not if it gives us a benefit.

[turansky]

It can be assumption of Gradle plugins, which process js-file before Webpack for example

[turansky]

I had such plugins before

[turansky]

@Artem Kobzar It works fine for parameters, but doesn't work for variables - is it expected?

[Edoardo Luppi]

Mmm interesting. You mean it doesn't capture local variables?

[turansky]

fun fn1() {
    doCall {} // works fine, local function created

    val fn2 = {} // top-level function created
}