kotlinlang #announcements

I think the reason is that nested functions can capture variables, and it needs it be defined before it it used otherwise it would capture undeclared variables.

👍 2

karelpeeters

04/14/2018, 7:26 AM

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fun foo() {
    val a = 3
    bar()
    val b = 7
    fun bar() { println(a+b) }
}

nfrankel

04/14/2018, 7:26 AM

perfect explanation thanks!

nfrankel

04/14/2018, 7:28 AM

i’ve changed it so now i have the reading order that i want:

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val client = Client("api", "key", "secret")

fun main(args: Array<String>) {

    ListVolume().run()
    ListFirewallRules().run()
}

fun Command.run() = client.execute(this).third.fold(
        { println(it) },
        { throw it })

it leaks more but is more readable imho

Diarmuid

04/14/2018, 8:03 AM

whats the best channel to discuss Gradle Kotlin DSL ?

Diarmuid

04/14/2018, 8:04 AM

anyone know of a good example of gradle kotlin dsl building a spring boot app?

karelpeeters

04/14/2018, 8:06 AM

#gradle probably

Diarmuid

04/14/2018, 8:17 AM

awkward 🙂

Diarmuid

04/14/2018, 8:17 AM

hehe

Diarmuid

04/14/2018, 8:18 AM

thanks

Nikita Kulikov

04/14/2018, 9:33 AM

Why Kotlin transform java interface to lambda, but not Kotlin Interface?

SiebelsTim

04/14/2018, 9:38 AM

Because you would want to use a higher order function for that. e.g.

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fun f(arg: () -> Unit) =...

However, there is a ticket open for SAM conversion for kotlin classes I believe.

Nikita Kulikov

04/14/2018, 9:40 AM

Where i can vote up for this?)

Nikita Kulikov

04/14/2018, 9:41 AM

Declare all interface body wherever we use listener - bad idea :3

SiebelsTim

04/14/2018, 9:59 AM

Declare all interface body wherever we use listener - bad idea :3

I don't think I understand what you mean. I do think that you can achieve what you want with higher order functions. Anyway, here's a Ticket for SAM for kotlin classes. https://youtrack.jetbrains.com/issue/KT-7770

karelpeeters

04/14/2018, 10:34 AM

You can also use typealiases, basically

typealias Runnable = () -> Unit

would be the equivalent to

java.lang.Runnable

Kulwinder Singh

04/14/2018, 11:34 AM

@Kulwinder Singh uploaded a file: why this function can't be `inlined` ?

why_this_function_can_t_be__inlined___.kt

Marcel Overdijk

04/14/2018, 11:36 AM

I'm assigning a

val

like:

val countryOfBirth: CountryResource? = if (person.countryOfBirth != null) CountryResource(person.countryOfBirth!!) else null

Marcel Overdijk

04/14/2018, 11:36 AM

the

person

is here a variable I get from the primary constructor

user

04/14/2018, 11:36 AM

@karelpeeters commented on @Kulwinder Singh’s file https://kotlinlang.slack.com/files/U5FHN1J7L/FA70DE0MB/why_this_function_can_t_be__inlined___.kt: What does it say?

why_this_function_can_t_be__inlined___.kt

Kulwinder Singh

04/14/2018, 11:42 AM

@karelpeeters

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can't inline onClicked here: it may conatain non-local returns, add crossinline modifier to parameter declaration onClicked

SiebelsTim

04/14/2018, 11:44 AM

person.countryOfBirth?.let { CountryResource(it) }

karelpeeters

04/14/2018, 11:52 AM

@Kulwinder Singh You "leak" the lamda out of the function, right? So it can't be inline. Mark the parameter

crossinline

or don't inline the function at all.

Kulwinder Singh

04/14/2018, 11:53 AM

ok, so is it worth to do

crossinline

or should i keep function simple

karelpeeters

04/14/2018, 11:58 AM

With crossinline your function will not inline anything in this case.

Kulwinder Singh

04/14/2018, 12:05 PM

so i only have one parameter as High-order function therefore it is not useful to use

crossinline

Kulwinder Singh

04/14/2018, 12:05 PM

thanks for help