kotlinlang #announcements

val onDone: () -> Unit = when (side) {
    LEFT -> {
        refreshLeftText.set(refreshText)
        {refreshLeftText.set("")}
    }
    RIGHT -> {
        refreshRightText.set(refreshText)
        {refreshRightText.set("")}
    }
}

So I have to do this:

Copy code

val onDone: () -> Unit

when (side) {
    LEFT -> {
        refreshLeftText.set(refreshText)
        onDone = {refreshLeftText.set("")}
    }
    RIGHT -> {
        refreshRightText.set(refreshText)
        onDone = {refreshRightText.set("")}
    }
}

I’m interested in making a contribution to fix this if you like. (if you guys help me!)

Olekss

02/14/2018, 9:27 AM

Where can I get example of kotlin serialization library doing kotlin map serialization into protobuf or something non JSON

gildor

02/14/2018, 9:28 AM

@Olekss https://github.com/Kotlin/kotlinx.serialization and #serialization

Olekss

02/14/2018, 9:30 AM

and which will be shorter protobuf or cbor?

aidanvii

02/14/2018, 10:33 AM

is there any way to make only certain warnings appear as errors? as opposed to using:

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kotlinOptions {
    allWarningsAsErrors = true
}

aidanvii

02/14/2018, 10:33 AM

for example, I don’t want to have to suppress all deprecation warnings

👍 1

Jimmy Alvarez

02/14/2018, 11:20 AM

Hello guys there is some Functional Programming channel?

Jimmy Alvarez

02/14/2018, 11:20 AM

For kotlin

dh44t

02/14/2018, 11:22 AM

#functional and #arrow

sindrenm

02/14/2018, 1:29 PM

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setOf(1, 2, 3).map { it * 0 } // # => List(0, 0, 0)

Is this intentional? It sounds counter-intuitive that the collection type changes when calling

map

from a

Set

sindrenm

02/14/2018, 1:30 PM

To be clear, I'd expect to get a

Set(0)

back, not a

List(0, 0, 0)

menegatti

02/14/2018, 1:32 PM

map

always returns a

List

marstran

02/14/2018, 1:32 PM

map

is an extension function on

Iterable<T>

which always returns a

List

sindrenm

02/14/2018, 1:33 PM

Yeah, but why? Languages like Haskell or Scala will return a set, AFAIK?

sindrenm

02/14/2018, 1:33 PM

Doesn't that sound more correct?

karelpeeters

02/14/2018, 1:33 PM

And think about it: what if map returned a list? It would automatically delete duplicate elements.

spand

02/14/2018, 1:33 PM

Because an order preserving map is nice

kevinmost

02/14/2018, 1:34 PM

LinkedHashSet

would preserve order too

bennofs

02/14/2018, 1:34 PM

order preserving? if you map over a hashset, there is no order to begin with

spand

02/14/2018, 1:34 PM

There is always an iteration order

marstran

02/14/2018, 1:35 PM

I think part of the contract of the

map

function is that the resulting collection has to have the same number of elements.

karelpeeters

02/14/2018, 1:36 PM

You can always

mapTo(mutableSetOf()) { ... }

robstoll

02/14/2018, 1:36 PM

@sindrenm you can use

setOf(1, 2, 3).asSequence().map { it * 0 }.toSet()

(in case you shouldn't know)

sindrenm

02/14/2018, 1:42 PM

And yeah, you may be right, @marstran.

sindrenm

02/14/2018, 1:43 PM

Apparently, Haskell doesn't have a core Set, but the one from Data seems to return a Set from a map.

Efe

02/14/2018, 1:51 PM

@Efe uploaded a file: Untitled

-.txt

menegatti

02/14/2018, 1:54 PM

you can use

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interface <in T> TaskListener {
    fun onTaskComplete(results: Map<Int, List<T>>)
}

which will prevent
T
from being erased at runtime, as opposed to the star projection which will give the compiler a tip that

is safe to be used as the type you passed

🤘 1

Efe

02/14/2018, 1:58 PM

I do not want to change the interface, because some java classes are also implementing it. But thanks, I think that will be the implementation that we should use at the end of the day

karelpeeters

02/14/2018, 2:01 PM

@menegatti

which will prevent
T
from being erased at runtime, as opposed to the star projection

What? Don't generics always get erased?