MutableList

interface MutableList<E> : List<E>, MutableCollection<E> (source)

A generic ordered collection of elements that supports adding and removing elements.

Parameters

E - the type of elements contained in the list. The mutable list is invariant on its element type.

Inherited Properties

size

abstract val size: Int

Returns the size of the collection.

Functions

add

abstract fun add(element: E): Boolean

Adds the specified element to the collection.

abstract fun add(index: Int, element: E)

Inserts an element into the list at the specified index.

addAll

abstract fun addAll(elements: Collection<E>): Boolean

Adds all of the elements in the specified collection to this collection.

abstract fun addAll(
    index: Int,
    elements: Collection<E>
): Boolean

Inserts all of the elements in the specified collection elements into this list at the specified index.

clear

abstract fun clear()

Removes all elements from this collection.

listIterator

abstract fun listIterator(): MutableListIterator<E>

Returns a list iterator over the elements in this list (in proper sequence).

abstract fun listIterator(index: Int): MutableListIterator<E>

Returns a list iterator over the elements in this list (in proper sequence), starting at the specified index.

remove

abstract fun remove(element: E): Boolean

Removes a single instance of the specified element from this collection, if it is present.

removeAll

abstract fun removeAll(elements: Collection<E>): Boolean

Removes all of this collection's elements that are also contained in the specified collection.

removeAt

abstract fun removeAt(index: Int): E

Removes an element at the specified index from the list.

retainAll

abstract fun retainAll(elements: Collection<E>): Boolean

Retains only the elements in this collection that are contained in the specified collection.

set

abstract operator fun set(index: Int, element: E): E

Replaces the element at the specified position in this list with the specified element.

subList

abstract fun subList(
    fromIndex: Int,
    toIndex: Int
): MutableList<E>

Returns a view of the portion of this list between the specified fromIndex (inclusive) and toIndex (exclusive). The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa.

Inherited Functions

contains

abstract fun contains(element: E): Boolean

Checks if the specified element is contained in this collection.

containsAll

abstract fun containsAll(elements: Collection<E>): Boolean

Checks if all elements in the specified collection are contained in this collection.

get

abstract operator fun get(index: Int): E

Returns the element at the specified index in the list.

indexOf

abstract fun indexOf(element: E): Int

Returns the index of the first occurrence of the specified element in the list, or -1 if the specified element is not contained in the list.

isEmpty

abstract fun isEmpty(): Boolean

Returns true if the collection is empty (contains no elements), false otherwise.

iterator

abstract fun iterator(): Iterator<E>

Returns an iterator over the elements of this object.

lastIndexOf

abstract fun lastIndexOf(element: E): Int

Returns the index of the last occurrence of the specified element in the list, or -1 if the specified element is not contained in the list.

Extension Properties

indices

val Collection<*>.indices: IntRange

Returns an IntRange of the valid indices for this collection.

lastIndex

val <T> List<T>.lastIndex: Int

Returns the index of the last item in the list or -1 if the list is empty.

Extension Functions

addAll

fun <T> MutableCollection<in T>.addAll(
    elements: Iterable<T>
): Boolean

Adds all elements of the given elements collection to this MutableCollection.

fun <T> MutableCollection<in T>.addAll(
    elements: Sequence<T>
): Boolean

Adds all elements of the given elements sequence to this MutableCollection.

fun <T> MutableCollection<in T>.addAll(
    elements: Array<out T>
): Boolean

Adds all elements of the given elements array to this MutableCollection.

all

fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean

Returns true if all elements match the given predicate.

any

fun <T> Iterable<T>.any(): Boolean

Returns true if collection has at least one element.

fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean

Returns true if at least one element matches the given predicate.

asIterable

fun <T> Iterable<T>.asIterable(): Iterable<T>

Returns this collection as an Iterable.

asReversed

fun <T> MutableList<T>.asReversed(): MutableList<T>

Returns a reversed mutable view of the original mutable List. All changes made in the original list will be reflected in the reversed one and vice versa.

asSequence

fun <T> Iterable<T>.asSequence(): Sequence<T>

Creates a Sequence instance that wraps the original collection returning its elements when being iterated.

associate

fun <T, K, V> Iterable<T>.associate(
    transform: (T) -> Pair<K, V>
): Map<K, V>

Returns a Map containing key-value pairs provided by transform function applied to elements of the given collection.

associateBy

fun <T, K> Iterable<T>.associateBy(
    keySelector: (T) -> K
): Map<K, T>

Returns a Map containing the elements from the given collection indexed by the key returned from keySelector function applied to each element.

fun <T, K, V> Iterable<T>.associateBy(
    keySelector: (T) -> K,
    valueTransform: (T) -> V
): Map<K, V>

Returns a Map containing the values provided by valueTransform and indexed by keySelector functions applied to elements of the given collection.

associateByTo

fun <T, K, M : MutableMap<in K, in T>> Iterable<T>.associateByTo(
    destination: M,
    keySelector: (T) -> K
): M

Populates and returns the destination mutable map with key-value pairs, where key is provided by the keySelector function applied to each element of the given collection and value is the element itself.

fun <T, K, V, M : MutableMap<in K, in V>> Iterable<T>.associateByTo(
    destination: M,
    keySelector: (T) -> K,
    valueTransform: (T) -> V
): M

Populates and returns the destination mutable map with key-value pairs, where key is provided by the keySelector function and and value is provided by the valueTransform function applied to elements of the given collection.

associateTo

fun <T, K, V, M : MutableMap<in K, in V>> Iterable<T>.associateTo(
    destination: M,
    transform: (T) -> Pair<K, V>
): M

Populates and returns the destination mutable map with key-value pairs provided by transform function applied to each element of the given collection.

binarySearch

fun <T : Comparable<T>> List<T?>.binarySearch(
    element: T?,
    fromIndex: Int = 0,
    toIndex: Int = size
): Int

Searches this list or its range for the provided element using the binary search algorithm. The list is expected to be sorted into ascending order according to the Comparable natural ordering of its elements, otherwise the result is undefined.

fun <T> List<T>.binarySearch(
    element: T,
    comparator: Comparator<in T>,
    fromIndex: Int = 0,
    toIndex: Int = size
): Int
fun <T> List<T>.binarySearch(
    element: T,
    comparator: Comparator<in T>,
    fromIndex: Int = 0,
    toIndex: Int = size
): Int

Searches this list or its range for the provided element using the binary search algorithm. The list is expected to be sorted into ascending order according to the specified comparator, otherwise the result is undefined.

fun <T> List<T>.binarySearch(
    fromIndex: Int = 0,
    toIndex: Int = size,
    comparison: (T) -> Int
): Int

Searches this list or its range for an element for which comparison function returns zero using the binary search algorithm. The list is expected to be sorted into ascending order according to the provided comparison, otherwise the result is undefined.

binarySearchBy

fun <T, K : Comparable<K>> List<T>.binarySearchBy(
    key: K?,
    fromIndex: Int = 0,
    toIndex: Int = size,
    selector: (T) -> K?
): Int

Searches this list or its range for an element having the key returned by the specified selector function equal to the provided key value using the binary search algorithm. The list is expected to be sorted into ascending order according to the Comparable natural ordering of keys of its elements. otherwise the result is undefined.

chunked

fun <T> Iterable<T>.chunked(size: Int): List<List<T>>

Splits this collection into a list of lists each not exceeding the given size.

fun <T, R> Iterable<T>.chunked(
    size: Int,
    transform: (List<T>) -> R
): List<R>

Splits this collection into several lists each not exceeding the given size and applies the given transform function to an each.

component1

operator fun <T> List<T>.component1(): T

Returns 1st element from the collection.

component2

operator fun <T> List<T>.component2(): T

Returns 2nd element from the collection.

component3

operator fun <T> List<T>.component3(): T

Returns 3rd element from the collection.

component4

operator fun <T> List<T>.component4(): T

Returns 4th element from the collection.

component5

operator fun <T> List<T>.component5(): T

Returns 5th element from the collection.

contains

operator fun <T> Iterable<T>.contains(element: T): Boolean

Returns true if element is found in the collection.

containsAll

fun <T> Collection<T>.containsAll(
    elements: Collection<T>
): Boolean

Checks if all elements in the specified collection are contained in this collection.

count

fun <T> Iterable<T>.count(predicate: (T) -> Boolean): Int

Returns the number of elements matching the given predicate.

distinct

fun <T> Iterable<T>.distinct(): List<T>

Returns a list containing only distinct elements from the given collection.

distinctBy

fun <T, K> Iterable<T>.distinctBy(
    selector: (T) -> K
): List<T>

Returns a list containing only elements from the given collection having distinct keys returned by the given selector function.

drop

fun <T> Iterable<T>.drop(n: Int): List<T>

Returns a list containing all elements except first n elements.

dropLast

fun <T> List<T>.dropLast(n: Int): List<T>

Returns a list containing all elements except last n elements.

dropLastWhile

fun <T> List<T>.dropLastWhile(
    predicate: (T) -> Boolean
): List<T>

Returns a list containing all elements except last elements that satisfy the given predicate.

dropWhile

fun <T> Iterable<T>.dropWhile(
    predicate: (T) -> Boolean
): List<T>

Returns a list containing all elements except first elements that satisfy the given predicate.

elementAtOrElse

fun <T> Iterable<T>.elementAtOrElse(
    index: Int,
    defaultValue: (Int) -> T
): T

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this collection.

fun <T> List<T>.elementAtOrElse(
    index: Int,
    defaultValue: (Int) -> T
): T

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this list.

fill

fun <T> MutableList<T>.fill(value: T)

Fills the list with the provided value.

filter

fun <T> Iterable<T>.filter(
    predicate: (T) -> Boolean
): List<T>

Returns a list containing only elements matching the given predicate.

filterIndexed

fun <T> Iterable<T>.filterIndexed(
    predicate: (index: Int, T) -> Boolean
): List<T>

Returns a list containing only elements matching the given predicate.

filterIndexedTo

fun <T, C : MutableCollection<in T>> Iterable<T>.filterIndexedTo(
    destination: C,
    predicate: (index: Int, T) -> Boolean
): C

Appends all elements matching the given predicate to the given destination.

filterIsInstance

fun <R> Iterable<*>.filterIsInstance(): List<R>

Returns a list containing all elements that are instances of specified type parameter R.

fun <R> Iterable<*>.filterIsInstance(
    klass: Class<R>
): List<R>

Returns a list containing all elements that are instances of specified class.

filterIsInstanceTo

fun <R, C : MutableCollection<in R>> Iterable<*>.filterIsInstanceTo(
    destination: C
): C

Appends all elements that are instances of specified type parameter R to the given destination.

fun <C : MutableCollection<in R>, R> Iterable<*>.filterIsInstanceTo(
    destination: C,
    klass: Class<R>
): C

Appends all elements that are instances of specified class to the given destination.

filterNot

fun <T> Iterable<T>.filterNot(
    predicate: (T) -> Boolean
): List<T>

Returns a list containing all elements not matching the given predicate.

filterNotNull

fun <T : Any> Iterable<T?>.filterNotNull(): List<T>

Returns a list containing all elements that are not null.

filterNotNullTo

fun <C : MutableCollection<in T>, T : Any> Iterable<T?>.filterNotNullTo(
    destination: C
): C

Appends all elements that are not null to the given destination.

filterNotTo

fun <T, C : MutableCollection<in T>> Iterable<T>.filterNotTo(
    destination: C,
    predicate: (T) -> Boolean
): C

Appends all elements not matching the given predicate to the given destination.

filterTo

fun <T, C : MutableCollection<in T>> Iterable<T>.filterTo(
    destination: C,
    predicate: (T) -> Boolean
): C

Appends all elements matching the given predicate to the given destination.

find

fun <T> Iterable<T>.find(predicate: (T) -> Boolean): T?

Returns the first element matching the given predicate, or null if no such element was found.

findLast

fun <T> Iterable<T>.findLast(predicate: (T) -> Boolean): T?
fun <T> List<T>.findLast(predicate: (T) -> Boolean): T?

Returns the last element matching the given predicate, or null if no such element was found.

first

fun <T> Iterable<T>.first(predicate: (T) -> Boolean): T

Returns the first element matching the given predicate.

firstOrNull

fun <T> Iterable<T>.firstOrNull(
    predicate: (T) -> Boolean
): T?

Returns the first element matching the given predicate, or null if element was not found.

flatMap

fun <T, R> Iterable<T>.flatMap(
    transform: (T) -> Iterable<R>
): List<R>

Returns a single list of all elements yielded from results of transform function being invoked on each element of original collection.

flatMapTo

fun <T, R, C : MutableCollection<in R>> Iterable<T>.flatMapTo(
    destination: C,
    transform: (T) -> Iterable<R>
): C

Appends all elements yielded from results of transform function being invoked on each element of original collection, to the given destination.

fold

fun <T, R> Iterable<T>.fold(
    initial: R,
    operation: (acc: R, T) -> R
): R

Accumulates value starting with initial value and applying operation from left to right to current accumulator value and each element.

foldIndexed

fun <T, R> Iterable<T>.foldIndexed(
    initial: R,
    operation: (index: Int, acc: R, T) -> R
): R

Accumulates value starting with initial value and applying operation from left to right to current accumulator value and each element with its index in the original collection.

foldRight

fun <T, R> List<T>.foldRight(
    initial: R,
    operation: (T, acc: R) -> R
): R

Accumulates value starting with initial value and applying operation from right to left to each element and current accumulator value.

foldRightIndexed

fun <T, R> List<T>.foldRightIndexed(
    initial: R,
    operation: (index: Int, T, acc: R) -> R
): R

Accumulates value starting with initial value and applying operation from right to left to each element with its index in the original list and current accumulator value.

forEach

fun <T> Iterable<T>.forEach(action: (T) -> Unit)

Performs the given action on each element.

forEachIndexed

fun <T> Iterable<T>.forEachIndexed(
    action: (index: Int, T) -> Unit)

Performs the given action on each element, providing sequential index with the element.

getOrElse

fun <T> List<T>.getOrElse(
    index: Int,
    defaultValue: (Int) -> T
): T

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this list.

getOrNull

fun <T> List<T>.getOrNull(index: Int): T?

Returns an element at the given index or null if the index is out of bounds of this list.

groupBy

fun <T, K> Iterable<T>.groupBy(
    keySelector: (T) -> K
): Map<K, List<T>>

Groups elements of the original collection by the key returned by the given keySelector function applied to each element and returns a map where each group key is associated with a list of corresponding elements.

fun <T, K, V> Iterable<T>.groupBy(
    keySelector: (T) -> K,
    valueTransform: (T) -> V
): Map<K, List<V>>

Groups values returned by the valueTransform function applied to each element of the original collection by the key returned by the given keySelector function applied to the element and returns a map where each group key is associated with a list of corresponding values.

groupByTo

fun <T, K, M : MutableMap<in K, MutableList<T>>> Iterable<T>.groupByTo(
    destination: M,
    keySelector: (T) -> K
): M

Groups elements of the original collection by the key returned by the given keySelector function applied to each element and puts to the destination map each group key associated with a list of corresponding elements.

fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Iterable<T>.groupByTo(
    destination: M,
    keySelector: (T) -> K,
    valueTransform: (T) -> V
): M

Groups values returned by the valueTransform function applied to each element of the original collection by the key returned by the given keySelector function applied to the element and puts to the destination map each group key associated with a list of corresponding values.

groupingBy

fun <T, K> Iterable<T>.groupingBy(
    keySelector: (T) -> K
): Grouping<T, K>

Creates a Grouping source from a collection to be used later with one of group-and-fold operations using the specified keySelector function to extract a key from each element.

indexOf

fun <T> Iterable<T>.indexOf(element: T): Int

Returns first index of element, or -1 if the collection does not contain element.

fun <T> List<T>.indexOf(element: T): Int

Returns first index of element, or -1 if the list does not contain element.

indexOfFirst

fun <T> Iterable<T>.indexOfFirst(
    predicate: (T) -> Boolean
): Int

Returns index of the first element matching the given predicate, or -1 if the collection does not contain such element.

fun <T> List<T>.indexOfFirst(predicate: (T) -> Boolean): Int

Returns index of the first element matching the given predicate, or -1 if the list does not contain such element.

indexOfLast

fun <T> Iterable<T>.indexOfLast(
    predicate: (T) -> Boolean
): Int

Returns index of the last element matching the given predicate, or -1 if the collection does not contain such element.

fun <T> List<T>.indexOfLast(predicate: (T) -> Boolean): Int

Returns index of the last element matching the given predicate, or -1 if the list does not contain such element.

intersect

infix fun <T> Iterable<T>.intersect(
    other: Iterable<T>
): Set<T>

Returns a set containing all elements that are contained by both this set and the specified collection.

isNotEmpty

fun <T> Collection<T>.isNotEmpty(): Boolean

Returns true if the collection is not empty.

joinTo

fun <T, A> Iterable<T>.joinTo(
    buffer: A,
    separator: CharSequence = ", ",
    prefix: CharSequence = "",
    postfix: CharSequence = "",
    limit: Int = -1,
    truncated: CharSequence = "...",
    transform: (T) -> CharSequence = null
): A

Appends the string from all the elements separated using separator and using the given prefix and postfix if supplied.

joinToString

fun <T> Iterable<T>.joinToString(
    separator: CharSequence = ", ",
    prefix: CharSequence = "",
    postfix: CharSequence = "",
    limit: Int = -1,
    truncated: CharSequence = "...",
    transform: (T) -> CharSequence = null
): String

Creates a string from all the elements separated using separator and using the given prefix and postfix if supplied.

last

fun <T> Iterable<T>.last(predicate: (T) -> Boolean): T
fun <T> List<T>.last(predicate: (T) -> Boolean): T

Returns the last element matching the given predicate.

lastIndexOf

fun <T> Iterable<T>.lastIndexOf(element: T): Int

Returns last index of element, or -1 if the collection does not contain element.

fun <T> List<T>.lastIndexOf(element: T): Int

Returns last index of element, or -1 if the list does not contain element.

lastOrNull

fun <T> Iterable<T>.lastOrNull(predicate: (T) -> Boolean): T?
fun <T> List<T>.lastOrNull(predicate: (T) -> Boolean): T?

Returns the last element matching the given predicate, or null if no such element was found.

map

fun <T, R> Iterable<T>.map(transform: (T) -> R): List<R>

Returns a list containing the results of applying the given transform function to each element in the original collection.

mapIndexed

fun <T, R> Iterable<T>.mapIndexed(
    transform: (index: Int, T) -> R
): List<R>

Returns a list containing the results of applying the given transform function to each element and its index in the original collection.

mapIndexedNotNull

fun <T, R : Any> Iterable<T>.mapIndexedNotNull(
    transform: (index: Int, T) -> R?
): List<R>

Returns a list containing only the non-null results of applying the given transform function to each element and its index in the original collection.

mapIndexedNotNullTo

fun <T, R : Any, C : MutableCollection<in R>> Iterable<T>.mapIndexedNotNullTo(
    destination: C,
    transform: (index: Int, T) -> R?
): C

Applies the given transform function to each element and its index in the original collection and appends only the non-null results to the given destination.

mapIndexedTo

fun <T, R, C : MutableCollection<in R>> Iterable<T>.mapIndexedTo(
    destination: C,
    transform: (index: Int, T) -> R
): C

Applies the given transform function to each element and its index in the original collection and appends the results to the given destination.

mapNotNull

fun <T, R : Any> Iterable<T>.mapNotNull(
    transform: (T) -> R?
): List<R>

Returns a list containing only the non-null results of applying the given transform function to each element in the original collection.

mapNotNullTo

fun <T, R : Any, C : MutableCollection<in R>> Iterable<T>.mapNotNullTo(
    destination: C,
    transform: (T) -> R?
): C

Applies the given transform function to each element in the original collection and appends only the non-null results to the given destination.

mapTo

fun <T, R, C : MutableCollection<in R>> Iterable<T>.mapTo(
    destination: C,
    transform: (T) -> R
): C

Applies the given transform function to each element of the original collection and appends the results to the given destination.

max

fun <T : Comparable<T>> Iterable<T>.max(): T?

Returns the largest element or null if there are no elements.

maxBy

fun <T, R : Comparable<R>> Iterable<T>.maxBy(
    selector: (T) -> R
): T?

Returns the first element yielding the largest value of the given function or null if there are no elements.

maxWith

fun <T> Iterable<T>.maxWith(comparator: Comparator<in T>): T?
fun <T> Iterable<T>.maxWith(comparator: Comparator<in T>): T?

Returns the first element having the largest value according to the provided comparator or null if there are no elements.

min

fun <T : Comparable<T>> Iterable<T>.min(): T?

Returns the smallest element or null if there are no elements.

minBy

fun <T, R : Comparable<R>> Iterable<T>.minBy(
    selector: (T) -> R
): T?

Returns the first element yielding the smallest value of the given function or null if there are no elements.

minWith

fun <T> Iterable<T>.minWith(comparator: Comparator<in T>): T?
fun <T> Iterable<T>.minWith(comparator: Comparator<in T>): T?

Returns the first element having the smallest value according to the provided comparator or null if there are no elements.

minus

operator fun <T> Iterable<T>.minus(element: T): List<T>

Returns a list containing all elements of the original collection without the first occurrence of the given element.

operator fun <T> Iterable<T>.minus(
    elements: Array<out T>
): List<T>

Returns a list containing all elements of the original collection except the elements contained in the given elements array.

operator fun <T> Iterable<T>.minus(
    elements: Iterable<T>
): List<T>

Returns a list containing all elements of the original collection except the elements contained in the given elements collection.

operator fun <T> Iterable<T>.minus(
    elements: Sequence<T>
): List<T>

Returns a list containing all elements of the original collection except the elements contained in the given elements sequence.

minusAssign

operator fun <T> MutableCollection<in T>.minusAssign(
    element: T)

Removes a single instance of the specified element from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    elements: Iterable<T>)

Removes all elements contained in the given elements collection from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    elements: Array<T>)

Removes all elements contained in the given elements array from this mutable collection.

operator fun <T> MutableCollection<in T>.minusAssign(
    elements: Sequence<T>)

Removes all elements contained in the given elements sequence from this mutable collection.

minusElement

fun <T> Iterable<T>.minusElement(element: T): List<T>

Returns a list containing all elements of the original collection without the first occurrence of the given element.

none

fun <T> Iterable<T>.none(): Boolean

Returns true if the collection has no elements.

fun <T> Iterable<T>.none(predicate: (T) -> Boolean): Boolean

Returns true if no elements match the given predicate.

partition

fun <T> Iterable<T>.partition(
    predicate: (T) -> Boolean
): Pair<List<T>, List<T>>

Splits the original collection into pair of lists, where first list contains elements for which predicate yielded true, while second list contains elements for which predicate yielded false.

plus

operator fun <T> Iterable<T>.plus(element: T): List<T>
operator fun <T> Collection<T>.plus(element: T): List<T>

Returns a list containing all elements of the original collection and then the given element.

operator fun <T> Iterable<T>.plus(
    elements: Array<out T>
): List<T>
operator fun <T> Collection<T>.plus(
    elements: Array<out T>
): List<T>

Returns a list containing all elements of the original collection and then all elements of the given elements array.

operator fun <T> Iterable<T>.plus(
    elements: Iterable<T>
): List<T>
operator fun <T> Collection<T>.plus(
    elements: Iterable<T>
): List<T>

Returns a list containing all elements of the original collection and then all elements of the given elements collection.

operator fun <T> Iterable<T>.plus(
    elements: Sequence<T>
): List<T>
operator fun <T> Collection<T>.plus(
    elements: Sequence<T>
): List<T>

Returns a list containing all elements of the original collection and then all elements of the given elements sequence.

plusAssign

operator fun <T> MutableCollection<in T>.plusAssign(
    element: T)

Adds the specified element to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    elements: Iterable<T>)

Adds all elements of the given elements collection to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    elements: Array<T>)

Adds all elements of the given elements array to this mutable collection.

operator fun <T> MutableCollection<in T>.plusAssign(
    elements: Sequence<T>)

Adds all elements of the given elements sequence to this mutable collection.

plusElement

fun <T> Iterable<T>.plusElement(element: T): List<T>
fun <T> Collection<T>.plusElement(element: T): List<T>

Returns a list containing all elements of the original collection and then the given element.

reduce

fun <S, T : S> Iterable<T>.reduce(
    operation: (acc: S, T) -> S
): S

Accumulates value starting with the first element and applying operation from left to right to current accumulator value and each element.

reduceIndexed

fun <S, T : S> Iterable<T>.reduceIndexed(
    operation: (index: Int, acc: S, T) -> S
): S

Accumulates value starting with the first element and applying operation from left to right to current accumulator value and each element with its index in the original collection.

reduceRight

fun <S, T : S> List<T>.reduceRight(
    operation: (T, acc: S) -> S
): S

Accumulates value starting with last element and applying operation from right to left to each element and current accumulator value.

reduceRightIndexed

fun <S, T : S> List<T>.reduceRightIndexed(
    operation: (index: Int, T, acc: S) -> S
): S

Accumulates value starting with last element and applying operation from right to left to each element with its index in the original list and current accumulator value.

remove

fun <T> MutableCollection<out T>.remove(element: T): Boolean

Removes a single instance of the specified element from this collection, if it is present.

removeAll

fun <T> MutableList<T>.removeAll(
    predicate: (T) -> Boolean
): Boolean

Removes all elements from this MutableList that match the given predicate.

fun <T> MutableCollection<out T>.removeAll(
    elements: Collection<T>
): Boolean

Removes all of this collection's elements that are also contained in the specified collection.

fun <T> MutableIterable<T>.removeAll(
    predicate: (T) -> Boolean
): Boolean

Removes all elements from this MutableIterable that match the given predicate.

fun <T> MutableCollection<in T>.removeAll(
    elements: Iterable<T>
): Boolean

Removes all elements from this MutableCollection that are also contained in the given elements collection.

fun <T> MutableCollection<in T>.removeAll(
    elements: Sequence<T>
): Boolean

Removes all elements from this MutableCollection that are also contained in the given elements sequence.

fun <T> MutableCollection<in T>.removeAll(
    elements: Array<out T>
): Boolean

Removes all elements from this MutableCollection that are also contained in the given elements array.

retainAll

fun <T> MutableList<T>.retainAll(
    predicate: (T) -> Boolean
): Boolean

Retains only elements of this MutableList that match the given predicate.

fun <T> MutableCollection<out T>.retainAll(
    elements: Collection<T>
): Boolean

Retains only the elements in this collection that are contained in the specified collection.

fun <T> MutableIterable<T>.retainAll(
    predicate: (T) -> Boolean
): Boolean

Retains only elements of this MutableIterable that match the given predicate.

fun <T> MutableCollection<in T>.retainAll(
    elements: Iterable<T>
): Boolean

Retains only elements of this MutableCollection that are contained in the given elements collection.

fun <T> MutableCollection<in T>.retainAll(
    elements: Array<out T>
): Boolean

Retains only elements of this MutableCollection that are contained in the given elements array.

fun <T> MutableCollection<in T>.retainAll(
    elements: Sequence<T>
): Boolean

Retains only elements of this MutableCollection that are contained in the given elements sequence.

reverse

fun <T> MutableList<T>.reverse()

Reverses elements in the list in-place.

reversed

fun <T> Iterable<T>.reversed(): List<T>

Returns a list with elements in reversed order.

shuffle

fun <T> MutableList<T>.shuffle()

Randomly shuffles elements in this mutable list.

fun <T> MutableList<T>.shuffle(random: Random)

Randomly shuffles elements in this mutable list using the specified random instance as the source of randomness.

shuffled

fun <T> Iterable<T>.shuffled(): List<T>

Returns a new list with the elements of this list randomly shuffled.

fun <T> Iterable<T>.shuffled(random: Random): List<T>

Returns a new list with the elements of this list randomly shuffled using the specified random instance as the source of randomness.

single

fun <T> Iterable<T>.single(predicate: (T) -> Boolean): T

Returns the single element matching the given predicate, or throws exception if there is no or more than one matching element.

singleOrNull

fun <T> Iterable<T>.singleOrNull(
    predicate: (T) -> Boolean
): T?

Returns the single element matching the given predicate, or null if element was not found or more than one element was found.

slice

fun <T> List<T>.slice(indices: IntRange): List<T>

Returns a list containing elements at indices in the specified indices range.

fun <T> List<T>.slice(indices: Iterable<Int>): List<T>

Returns a list containing elements at specified indices.

sort

fun <T : Comparable<T>> MutableList<T>.sort()

Sorts elements in the list in-place according to their natural sort order.

sortBy

fun <T, R : Comparable<R>> MutableList<T>.sortBy(
    selector: (T) -> R?)

Sorts elements in the list in-place according to natural sort order of the value returned by specified selector function.

sortByDescending

fun <T, R : Comparable<R>> MutableList<T>.sortByDescending(
    selector: (T) -> R?)

Sorts elements in the list in-place descending according to natural sort order of the value returned by specified selector function.

sortDescending

fun <T : Comparable<T>> MutableList<T>.sortDescending()

Sorts elements in the list in-place descending according to their natural sort order.

sortWith

fun <T> MutableList<T>.sortWith(comparator: Comparator<in T>)
fun <T> MutableList<T>.sortWith(comparator: Comparator<in T>)

Sorts elements in the list in-place according to the order specified with comparator.

sorted

fun <T : Comparable<T>> Iterable<T>.sorted(): List<T>

Returns a list of all elements sorted according to their natural sort order.

sortedBy

fun <T, R : Comparable<R>> Iterable<T>.sortedBy(
    selector: (T) -> R?
): List<T>

Returns a list of all elements sorted according to natural sort order of the value returned by specified selector function.

sortedByDescending

fun <T, R : Comparable<R>> Iterable<T>.sortedByDescending(
    selector: (T) -> R?
): List<T>

Returns a list of all elements sorted descending according to natural sort order of the value returned by specified selector function.

sortedDescending

fun <T : Comparable<T>> Iterable<T>.sortedDescending(): List<T>

Returns a list of all elements sorted descending according to their natural sort order.

sortedWith

fun <T> Iterable<T>.sortedWith(
    comparator: Comparator<in T>
): List<T>
fun <T> Iterable<T>.sortedWith(
    comparator: Comparator<in T>
): List<T>

Returns a list of all elements sorted according to the specified comparator.

subtract

infix fun <T> Iterable<T>.subtract(
    other: Iterable<T>
): Set<T>

Returns a set containing all elements that are contained by this collection and not contained by the specified collection.

sumBy

fun <T> Iterable<T>.sumBy(selector: (T) -> Int): Int

Returns the sum of all values produced by selector function applied to each element in the collection.

sumByDouble

fun <T> Iterable<T>.sumByDouble(
    selector: (T) -> Double
): Double

Returns the sum of all values produced by selector function applied to each element in the collection.

take

fun <T> Iterable<T>.take(n: Int): List<T>

Returns a list containing first n elements.

takeLast

fun <T> List<T>.takeLast(n: Int): List<T>

Returns a list containing last n elements.

takeLastWhile

fun <T> List<T>.takeLastWhile(
    predicate: (T) -> Boolean
): List<T>

Returns a list containing last elements satisfying the given predicate.

takeWhile

fun <T> Iterable<T>.takeWhile(
    predicate: (T) -> Boolean
): List<T>

Returns a list containing first elements satisfying the given predicate.

toCollection

fun <T, C : MutableCollection<in T>> Iterable<T>.toCollection(
    destination: C
): C

Appends all elements to the given destination collection.

toHashSet

fun <T> Iterable<T>.toHashSet(): HashSet<T>

Returns a HashSet of all elements.

toList

fun <T> Iterable<T>.toList(): List<T>

Returns a List containing all elements.

toMutableSet

fun <T> Iterable<T>.toMutableSet(): MutableSet<T>

Returns a mutable set containing all distinct elements from the given collection.

toSet

fun <T> Iterable<T>.toSet(): Set<T>

Returns a Set of all elements.

toSortedSet

fun <T : Comparable<T>> Iterable<T>.toSortedSet(): SortedSet<T>
fun <T> Iterable<T>.toSortedSet(
    comparator: Comparator<in T>
): SortedSet<T>

Returns a SortedSet of all elements.

toTypedArray

fun <T> Collection<T>.toTypedArray(): Array<T>

Returns a typed array containing all of the elements of this collection.

union

infix fun <T> Iterable<T>.union(other: Iterable<T>): Set<T>

Returns a set containing all distinct elements from both collections.

windowed

fun <T> Iterable<T>.windowed(
    size: Int,
    step: Int = 1,
    partialWindows: Boolean = false
): List<List<T>>

Returns a list of snapshots of the window of the given size sliding along this collection with the given step, where each snapshot is a list.

fun <T, R> Iterable<T>.windowed(
    size: Int,
    step: Int = 1,
    partialWindows: Boolean = false,
    transform: (List<T>) -> R
): List<R>

Returns a list of results of applying the given transform function to an each list representing a view over the window of the given size sliding along this collection with the given step.

withIndex

fun <T> Iterable<T>.withIndex(): Iterable<IndexedValue<T>>

Returns a lazy Iterable of IndexedValue for each element of the original collection.

zip

infix fun <T, R> Iterable<T>.zip(
    other: Array<out R>
): List<Pair<T, R>>
infix fun <T, R> Iterable<T>.zip(
    other: Iterable<R>
): List<Pair<T, R>>

Returns a list of pairs built from elements of both collections with same indexes. List has length of shortest collection.

fun <T, R, V> Iterable<T>.zip(
    other: Array<out R>,
    transform: (a: T, b: R) -> V
): List<V>
fun <T, R, V> Iterable<T>.zip(
    other: Iterable<R>,
    transform: (a: T, b: R) -> V
): List<V>

Returns a list of values built from elements of both collections with same indexes using provided transform. List has length of shortest collection.

zipWithNext

fun <T> Iterable<T>.zipWithNext(): List<Pair<T, T>>

Returns a list of pairs of each two adjacent elements in this collection.

fun <T, R> Iterable<T>.zipWithNext(
    transform: (a: T, b: T) -> R
): List<R>

Returns a list containing the results of applying the given transform function to an each pair of two adjacent elements in this collection.

Inheritors

AbstractMutableList

abstract class AbstractMutableList<E> : 
    MutableList<E>,
    AbstractList<E>

Provides a skeletal implementation of the MutableList interface.