use

is an extension function on

Closeable

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/use.html

does

Session

implements it?

ah I see how it works. No, it does not. I'll submit a PR to

org.neo4j.driver.v1.Session

Is there a way for a pure java class to implement that?

(I think neo4j core is all Java and Scala, though they use a lot of Kotlin for other modules)

You can write own

use

implementation for this class (or some other interface, implemented by Session)

as an extension? ok yup. But can it be pure java to go in their codebase? So others can benefit?

any example of a use impl? gist or something?

Oh I see, Session implements AutoCloseable, so you already can use

use

just add dependency on

org.jetbrains.kotlin:kotlin-stdlib-jre7

(or jre8 if you use Java 8)

ah right!

thank you

(works now)

Golang got this number down to 3

Are you talking actual CPU register changes? I don't think you'll ever get that low-level on the JVM.

Anyway, #coroutines might be a better fit.

Yeah, just curious

The other guys at golang are all over the place advertising that

:P

you would have to use a debug JVM and ask it to show you the compiled assembly. i doubt anyone has looked at that.

you'd start by getting a feel for the weight of the bytecode.

that said, it seems like an odd benchmark to optimise for. as is so often the case with golang.... seems they picked a single metric and optimised for it like crazy without it being entirely clear why or what the tradeoffs are.

there's a coroutines channel where they might be able to answer that question in more detail

lets say I have this enum

enum class Color(val name: String) {
        RED("red"),
        GREEN("green"),
        BLUE("blue")
}

and I would like to have a function which tells me whether the name corresponds to any of the enum instances:

isContainedInEnum("blue") == true

Any good way to do this? The syntax can be a bit different if needed.

create a companion object inside color with a method that takes a string, iterate over

Color.values

and check each name against the method's argument

yeah so companion object.. 😞

Can't you also just create a function outside of the object?

You could try using sealed classes and implementing an equals method that accepts both

Color

and

String

I would understand not allowing

===

, but

==

seems weird

Has anyone tried creating a Java 9 module that depends on a Kotlin module? The Kotlin module depends on kotlin-stdlib-jre8, but that gives me a lot of these errors:

Error:java: module kotlin.stdlib.jre8 reads package kotlin from both kotlin.stdlib and kotlin.stdlib.jre7.

Not depending on

stdlib-jre8

isn't an option?