Kotlin Multiplatform Bounded Open/Closed Generic Intervals

Represent closed, open, or half-open, bounded intervals in Kotlin and perform common operations on them. Values covered by the interval can be of a different type than distances between those values.

For example, IntInterval has Int values and UInt distances:

val interval: IntInterval = interval( 0, 10, isEndIncluded = false )
val areIncluded = 0 in interval && 5 in interval // true
val areExcluded = 10 !in interval && 15 !in interval // true
val size: UInt = interval.size // 10

This protects against overflows (e.g. if size > Int.MAX_VALUE) but also offers better semantics. For example, this library supports kotlinx datetime Instant values which are a Duration apart.

val now = Clock.System.now()
val interval: InstantInterval = interval( now, now + 100.seconds )
val areIncluded = now + 50.seconds in interval // true
val size: Duration = interval.size // 100 seconds

Interval Types

This library includes a generic base class Interval<T, TSize> which can be used to create intervals for any type. To achieve this, it directs type operations to IntervalTypeOperations which the constructor takes as a parameter.

The following interval types are included in io.github.whathecode.kotlinx.interval:kotlinx-interval on Maven:

Type	Values (T)	Distances (TSize)
ByteInterval	Byte	UByte
ShortInterval	Short	UShort
IntInterval	Int	UInt
LongInterval	Long	ULong
FloatInterval	Float	Double
DoubleInterval	Double	Double
UByteInterval	UByte	UByte
UShortInterval	UShort	UShort
UIntInterval	UInt	UInt
ULongInterval	ULong	ULong
CharInterval	Char	UShort

Date/time intervals

Date/time intervals are implemented as InstantInterval using the kotlinx datetime library. Since you may not always want to pull in this dependency, this class is published separately in io.github.whathecode.kotlinx.interval:kotlinx-interval-datetime.