Duration utils in Kotlin

Duration+Ext.kt

val Int.nano: Duration
    get() = ofNanos(this.toLong())
val Int.nanos: Duration
    get() = ofNanos(this.toLong())
val Long.nano: Duration
    get() = ofNanos(this)
val Long.nanos: Duration
    get() = ofNanos(this)

val Int.milli: Duration
    get() = ofMillis(this.toLong())
val Int.millis: Duration
    get() = ofMillis(this.toLong())
val Long.milli: Duration
    get() = ofMillis(this)
val Long.millis: Duration
    get() = ofMillis(this)

val Int.second: Duration
    get() = ofSeconds(this.toLong())
val Int.seconds: Duration
    get() = ofSeconds(this.toLong())
val Long.second: Duration
    get() = ofSeconds(this)
val Long.seconds: Duration
    get() = ofSeconds(this)

val Int.minute: Duration
    get() = ofMinutes(this.toLong())
val Int.minutes: Duration
    get() = ofMinutes(this.toLong())
val Long.minute: Duration
    get() = ofMinutes(this)
val Long.minutes: Duration
    get() = ofMinutes(this)

private val unitLabels = listOf(
    NANOS to "ns",
    MICROS to "µs",
    MILLIS to "ms",
    SECONDS to "s",
    MINUTES to "min",
    HOURS to "h",
    DAYS to " days",
    MONTHS to " months",
    YEARS to " years",
    CENTURIES to " centuries",
    FOREVER to " ∞"
)

fun Duration.humanize(depth: Int = 2): String {
    require(depth > 0) { "Require a depth strictly positive" }

    tailrec fun aux(depth: Int, duration: Duration, acc: String): String =
        if (depth == 0 || duration.isZero) acc
        else {
            val (tu, unit) = unitLabels.lastOrNull() { (tu, _) ->
                tu.duration < duration
            } ?: unitLabels.last()
            val value = duration.toNanos() / tu.duration.toNanos()
            val rest = duration.toNanos() % tu.duration.toNanos()
            aux(depth - 1, ofNanos(rest), if (acc.isEmpty()) "$value$unit" else "$acc $value$unit")
        }
    return aux(depth, this, "")
}


inline fun <T> elapsed(consumer: (Duration) -> Unit = { println("Took ${it.humanize()}") }, block: () -> T): T {
    val start = System.nanoTime()
    try {
        return block()
    } finally {
        val duration = ofNanos(System.nanoTime() - start)
        consumer(duration)
    }
}