Should I extend java math Biginteger and alias that Edit hmm kotlinlang #multiplatform

Should I extend java.math.Biginteger and alias that? Edit; hmm that doesnt seem to work out, return types etc are different class because of extending. Don't see how I add this companion object values to the type-alias...

Dico

12/27/2018, 9:52 AM

You have to remove the expected declaration for NEGATIVE_ONE to use the typealias

Robert

12/27/2018, 5:46 PM

But if I want to add it? I guess I would not have to do the whole Java implementation of BigInteger myself? Should be some way to just extend it right?

Dico

12/27/2018, 8:24 PM

This is something I've wondered as well.

Robert

12/27/2018, 8:45 PM

Ah, I see. Hopefully someone comes around who knows. Otherwise I should just open an issue with YouTrack I guess?

If only this was possible, I would be very close

Copy code

actual typealias BigInteger = java.math.BigInteger
actual val BigInteger.Companion.NEGATIVE_ONE: BigInteger = BigInteger("-1")

Dico

12/28/2018, 12:46 AM

I suggest that you define them as such in common code.

Robert

12/28/2018, 5:45 AM

I don't have Java

java.math.BigInteger

in the common code. Also tried extending the companion object on the

java.math.BigInteger

in the JVM code, but it is unknown

Dico

12/28/2018, 2:57 PM

Well, there is a workaround, it's right in front of you, it's just a little bit ugly

For example you can move NEGATIVE_ONE to a top level extension property and make it expect if you have platform specific implementation

Robert

12/28/2018, 5:25 PM

How would that look like? I told I tried everything. I'll put it on GitHub later.

Do you mean in the expected class or in the actual (jvm) "class"/typealias. I tried all these variants in the jvm file: https://gist.github.com/RdeWilde/3c76bd09360132dd611dc23cd21b2c2c but ofc none matches the compagnion object (which is unavaible for the extension). I put it in the companion object for efficienty

For now I added this

expect inline fun Int.toBigInteger() : BigInteger

as a workaround. It is syntactical almost same or better

-1.toBigInteger()

but I think it is way less efficient. Not sure if I can check/solve that

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