yes

hmm, good to know. So all those

toXXX()

basically does the copy thing, I suppose? 🤔

as far as I know, all

toXX()

create a shallow copy

and it’s a bit weird that mutableSet has

length

and Set has

size

it doesn't

are you sure you're not seeing a more specific type?

oh, wait, looks like I got some char set…

And a follow up question: what if I want to have a Table data structure to get and put data with multiple keys like this:

table.get(key1, key2)
table.save(key1, key2, value)

deepTable.get(key1, key2, key3)
deepTable.save(key1, key2, key3, value)

Is there some data format I could use in kotlin? 🤔

there is nothing native, but ultimately that's just a map with a composite key

and then add things like

typealias <K1, K2, V> Table<K1, K2, V> = Map<Pair<K1, K2>, V>

Why I cann’t do the same on put method? :S

In this code snippet, I define a listener via an anonymous class below my init block (which references it) and it won't compile, because

textWatcherListener

has not been defined yet:

init {
        TextView(applicationContext).addTextChangedListener(textWatcherListener)
    }

    val textWatcherListener = object: TextWatcher {
        override fun beforeTextChanged(a: CharSequence?, b: Int, c: Int, d: Int) {
        }

        override fun onTextChanged(a: CharSequence?, b: Int, c: Int, d: Int) {
        }

        override fun afterTextChanged(a: Editable?) {
        }

    }

However, if I put

textWatcherListener

first, it works fine. That's okay, but I'm just trying to understand the technical explanation for why it has to be first and why it can't resolve it at compile time?

A file was commented on

Oh also this is a super dumbed down example I'm not actually creating a textview with the app context, I just did it to get a snippet to show

@thatadamedwards `because they are initialized in the order they are defined inside the class https://kotlinlang.org/docs/reference/classes.html#constructors

Got it. I thought that was the case (as that's how it worked in practice) but I couldn't put my finger on the right documentation. Thanks.

Guys, a quick question. Is the

kotlin-stdlib

package preferred instead of

kotlin-stdlib-jdk8

if we would like compatibility with the latest Java version? https://mvnrepository.com/artifact/org.jetbrains.kotlin/kotlin-stdlib https://mvnrepository.com/artifact/org.jetbrains.kotlin/kotlin-stdlib-jdk8

the latter depends on the former

also maven central is search.maven.org. that is some random third-party website that is frequently out-of-date

looks like the spring startr is using https://jcenter.bintray.com

Is this the preferred one?

preferred for what?

`Hi! Anyone have workaround with parametrized Annotation in kotlin? Here is the problem: When you use annotations from dependencies they all goes throw Java Proxy with AnnotationInvocationHandler. In Java you don't have problem, cause you call annotationInstance.value(), but in Kotlin it converts into annotationInstance.value, so Proxy does not have that field, and Proxy:invokeHandler:invoke() is not called. Any ideas (except processing annotations with Java)?

Is it good practice to read test resource files via

File("src/test/resources/file.txt")

?

Yeah, unfortunately Kotlin doesn't have a "this type".

Are there any nice workarounds for this problem?

You can use extension functions in some cases:

fun <T : MyBaseClass> T.someFunction(): T

But you use polymorphism

No requirement to use inheritance, haven't though of this. Thanks! 🙂

Or rather, you loose dynamic dispatch.

Hi guys.