Comparator

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

Functions

compare

Common

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.

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

Extensions

reversed

Common

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

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

then

Common

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

Common

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

Common

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

Common

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

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

thenDescending

Common

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.