Comparator

expect fun interface Comparator<T>(source)

Provides a comparison function for imposing a total ordering between instances of the type T.

actual typealias Comparator = Comparator<T>

actual fun interface Comparator<T>

Functions

expect abstract fun compare(a: T, b: T): Int

Compares its two arguments for order. Returns zero if the arguments are equal, a negative number if the first argument is less than the second, or a positive number if the first argument is greater than the second.

actual abstract fun compare(a: T, b: T): Int

Extensions

reversed

fun <T> Comparator<T>.reversed(): Comparator<T>

Returns a comparator that imposes the reverse ordering of this comparator.

then

infix fun <T> Comparator<T>.then(comparator: Comparator<in T>): Comparator<T>

Combines this comparator and the given comparator such that the latter is applied only when the former considered values equal.

thenBy

inline fun <T> Comparator<T>.thenBy(crossinline selector: (T) -> Comparable<*>?): Comparator<T>

Creates a comparator comparing values after the primary comparator defined them equal. It uses the function to transform value to a Comparable instance for comparison.

inline fun <T, K> Comparator<T>.thenBy(comparator: Comparator<in K>, crossinline selector: (T) -> K): Comparator<T>

Creates a comparator comparing values after the primary comparator defined them equal. It uses the selector function to transform values and then compares them with the given comparator.

thenByDescending

inline fun <T> Comparator<T>.thenByDescending(crossinline selector: (T) -> Comparable<*>?): Comparator<T>

Creates a descending comparator using the primary comparator and the function to transform value to a Comparable instance for comparison.

inline fun <T, K> Comparator<T>.thenByDescending(comparator: Comparator<in K>, crossinline selector: (T) -> K): Comparator<T>

Creates a descending comparator comparing values after the primary comparator defined them equal. It uses the selector function to transform values and then compares them with the given comparator.

thenComparator

inline fun <T> Comparator<T>.thenComparator(crossinline comparison: (a: T, b: T) -> Int): Comparator<T>

Creates a comparator using the primary comparator and function to calculate a result of comparison.

thenDescending

infix fun <T> Comparator<T>.thenDescending(comparator: Comparator<in T>): Comparator<T>

Combines this comparator and the given comparator such that the latter is applied only when the former considered values equal.