kotlin's `Duration` has no `.between()` to get a d...

# announcements

[TwoClocks]

kotlin's Duration has no .between() to get a duration between instances. which is fine... but once I include the java.time.Duration all the nice kotlin extension functions like Int.inSeconds can't be found. Am I just stuck w/ the java ones if I need between() ?

[Luke]

There is a minus operator: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.time/-duration/minus.html

[TwoClocks]

that's for another duration. not getting a duration between two `instant`s

[TwoClocks]

unless instant extend duration?

[hfhbd]

create a range and use the in operator

[TwoClocks]

I'm not aware of a time-range. Is that maybe a JS thing? I'm targeting JVM.

[hfhbd]

val upper = 5.seconds
val lower = 2.seconds
if (3.seconds in lower..upper) {
    println("true 3")
}
if (1.seconds !in lower..upper) {
    println("true 1")
}

[rocketraman]

I had this issue too, and I need an actual Duration not a range. My solution was to alias import e.g. import java.time.Duration as JavaTimeDuration.

[rocketraman]

You can combine that import with an extension function on kotlin's Duration, so that you only need it one place.

[TwoClocks]

@rocketraman thanks!

[TwoClocks]

@hfhbd There is no use of an instant in your example. I'm trying to do this :
val start = Instant.now()
[... do something, time passes ... ]
val end = Instant.now()
val delta = Duration.between(start,end)
The kotlin duration doesn't have between()

[rocketraman]

@TwoClocks I do it like this:

fun ClosedRange<Instant>.duration(): Duration =
  JavaTimeDuration.between(start, endInclusive).toKotlinDuration()

[rocketraman]

which you can then use like this:

(start..end).duration()

[rocketraman]

As you've noted the Kotlin API so far has no way to subtract or add two `Instant`'s to get a Kotlin Duration, so I believe that is the best approach.

[rocketraman]

BTW, if all you're trying to do is measure how long that "do something" code takes, you could do instead:

val duration = measureTime { ... do something ... }

[rocketraman]

Or if that block returns a value measureTimedValue like this:

val (result, duration) = measureTimedValue { ... do something ... }