Is there a reason why ReadWriteProperty interface ...
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Big Chungus
10/26/2020, 5:07 PMIs there a reason why ReadWriteProperty interface does not extend ReadOnlyProperty?
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ephemient
10/26/2020, 5:08 PMyes it does? https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.properties/-read-write-property/
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interface ReadWriteProperty<in T, V> : ReadOnlyProperty<T, V>b
Big Chungus
10/26/2020, 5:09 PMOdd, intellij shows that it doesn't.
Big Chungus
10/26/2020, 5:12 PMimage.png
Big Chungus
10/26/2020, 5:14 PMGradle build is also failing. I'm on kotlin 1.3.72, though as it's a gradle plugin project.
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ephemient
10/26/2020, 5:18 PMhttps://youtrack.jetbrains.com/issue/KT-27729 changed in 1.4
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Big Chungus
10/26/2020, 5:18 PMThanks!
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Vampire
10/26/2020, 5:22 PMIf you target Gradle 6.8, you can use 1.4 🙂
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Big Chungus
10/26/2020, 5:22 PMIs it out yet? 😮
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Vampire
10/26/2020, 5:23 PMAh, no, not yet 😄
Vampire
10/26/2020, 5:23 PM6.7 was released 12 days ago
Vampire
10/26/2020, 5:23 PMBut 6.8 will have 1.4 embedded
👍 1
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Big Chungus
10/26/2020, 5:23 PMHow/where I can check supported kotlin version in each gradle version?
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Vampire
10/26/2020, 5:24 PMWell, at least from the JARs in the class path / distribution
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ephemient
10/26/2020, 5:24 PMalso you generally don't need to think about the ReadOnlyProperty/ReadWriteProperty interfaces. as the docs say, property delegation works with whatever .getValue()/.setValue() operator functions are in scope
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Vampire
10/26/2020, 5:25 PMDunno whether there is some table somewhere, I just know for 6.8 1.4 will be embedded, but I think still using 1.3 syntax for the Kotlin DSL, but you don't have conflicts anymore then when using 1.4 stuff in a pre-compiled script plugin and similar things
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Big Chungus
10/26/2020, 5:25 PM@ephemient I'm aware, however my use-case is taking these delegates as arguments, so I have to use the interfaces.
Big Chungus
10/26/2020, 5:26 PMBasically chained delegates with fallbacks
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internal class ChainedProperty<R, V>(
private var main: ReadWriteProperty<R, V?>,
private val fallback: ReadWriteProperty<R, V>
) : ReadWriteProperty<R, V> {
override fun getValue(thisRef: R, property: KProperty<*>): V {
return main.getValue(thisRef, property) ?: fallback.getValue(thisRef, property)
}
override fun setValue(thisRef: R, property: KProperty<*>, value: V) {
main.setValue(thisRef, property, value)
}
}
internal infix fun <R, V> ReadWriteProperty<R, V?>.or(fallback: ReadWriteProperty<R, V>) = ChainedProperty(this, fallback)Big Chungus
10/26/2020, 5:27 PMNow I'm forced to duplicate all that for ReadOnlyProperty
Big Chungus
10/26/2020, 5:28 PMGonna wait for gradle 6.8 I guess. Thanks guys!
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Vampire
10/26/2020, 5:28 PMUnfortunate that there are no denotable union types yet
Vampire
10/26/2020, 5:28 PMThat would probably also have helped
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Big Chungus
10/26/2020, 5:29 PMAh, yes. Although that'd be more of a hack 😄
type MyProp = ReadWriteProperty<R, V?> | ReadOnlyProperty<R, V?>e
ephemient
10/26/2020, 5:36 PMyou could somewhat reduce repetition by moving the logic out of the class (although you will have to do a bit of name mangling to keep the JVM happy)
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