Hello I have an `object` with constants defined as `const va kotlinlang #getting-started

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Title

Vitali Plagov

09/28/2021, 10:15 AM

Hello. I have an

object

with constants defined as

const val

. I want to get a list of all constants available in this object. Is there a convenient way to get them? I tried with reflection:

MyObjectWithConstant::class.declaredMemberProperties

Joffrey

09/28/2021, 10:17 AM

You could define your constants using a property delegate that registers them in a list or map. Something like this: https://kotlinlang.slack.com/archives/C0B8MA7FA/p1632152724002800?thread_ts=1632151317.001400&cid=C0B8MA7FA

ephemient

09/28/2021, 10:27 AM

can't have delegates with

const val

, so if that's important to you, you'll need to use other approaches like reflection or codegen

👍 1

Vitali Plagov

09/28/2021, 10:29 AM

Thanks! What is “Peter approaches”?

Joffrey

09/28/2021, 10:30 AM

Might be an auto-corrected "other" 😄

Vitali Plagov

09/28/2021, 10:31 AM

Don’t think that

const val

is so important

Thanks @Joffrey! I think your proposed solution will work for me!

ephemient

09/28/2021, 3:52 PM

autocorrect whyyyyy

anyhow, reflection isn't too hard:

MyObjectWithConstant::class.declaredMemberProperties.filter { it.isConst }.associate { it.name to it.call() }

but does have a downside of being limited to JVM only

👍 1

the delegate trick is interesting, you might want to make it

private

so nobody else can mess with it. I'd probably choose to do something with kapt/ksp to generate a table of constants at compile-time if I had to (it would work with

const

too)

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