Kotlin Duration API: custom DurationUnit

Language Design
1

Currently we can only use existing extensions: Int.minutes, Int.seconds, etc. What if I want to declare my own DurationUnit? For example, in Minecraft development everything is measured in ticks, 1 second == 20 ticks. There’s no way to do this right now. Duration constructor is internal, and Int.toDuration accepts fixed enum values. In Java 8 Date/Time API we can implement TemporalUnit interface and use, for example, Instant#truncatedTo with our custom TemporalUnit. Can this be achieved in Kotlin Duration and time measurement API?

2

If you introduce Int.ticks and Duration.inTicks extension properties, would that be enough to cover your use case?

1 Like
3

Yes, but I couldn’t find a way to do this

4

Just look at how these extensions are defined for Duration type and declare your own in your package, e.g.:

import kotlin.time.*

@ExperimentalTime
val Int.ticks: Duration get() = this.seconds / 20
@ExperimentalTime
val Duration.inTicks: Double get() = this.inSeconds * 20

fun main() {
    println(15.ticks)
    println(1.milliseconds.inTicks)
}
5

Didn’t think about using existing extensions. Thanks!