KtIterableExtensions<T> extension
Methods
-
all(bool predicate(T element))
→ bool
-
Returns
true if all elements match the given predicate.
-
any([bool predicate(T element)?])
→ bool
-
Returns
true if at least one element matches the given predicate.
-
asIterable()
→ KtIterable<T>
-
Returns this collection as an Iterable.
-
associate<K, V>(KtPair<K, V> transform(T))
→ KtMap<K, V>
-
Returns a Map containing key-value pairs provided by
transform function
applied to elements of the given collection.
-
associateBy<K>(K keySelector(T))
→ KtMap<K, T>
-
Returns a Map containing the elements from the given collection indexed by the key
returned from
keySelector function applied to each element.
-
associateByTo<K, V, M extends KtMutableMap<K, V>>(M destination, K keySelector(T), [V valueTransform(T)?])
→ 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.
-
associateByTransform<K, V>(K keySelector(T), V valueTransform(T))
→ KtMap<K, V>
-
Returns a Map containing the elements from the given collection indexed by the key
returned from
keySelector function applied to each element. The element can be transformed with valueTransform.
-
associateTo<K, V, M extends KtMutableMap<K, V>>(M destination, KtPair<K, V> transform(T))
→ M
-
Populates and returns the
destination mutable map with key-value pairs
provided by transform function applied to each element of the given collection.
-
associateWith<V>(V valueSelector(T))
→ KtMap<T, V>
-
Returns a Map where keys are elements from the given collection and values are
produced by the
valueSelector function applied to each element.
-
associateWithTo<V, M extends KtMutableMap>(M destination, V valueSelector(T))
→ M
-
Populates and returns the
destination mutable map with key-value pairs for each element of the given collection,
where key is the element itself and value is provided by the valueSelector function applied to that key.
-
averageBy(num selector(T))
→ double
-
Returns an average value produced by
selector function applied to each element in the collection.
-
cast<R>()
→ KtIterable<R>
-
Provides a view of this KtIterable as an iterable of
R instances.
-
chunked(int size)
→ KtList<KtList<T>>
-
Splits this collection into a list of lists each not exceeding the given
size.
-
chunkedTransform<R>(int size, R transform(KtList<T>))
→ KtList<R>
-
Splits this collection into several lists each not exceeding the given
size
and applies the given transform function to an each.
-
contains(T element)
→ bool
-
Returns
true if element is found in the collection.
-
count([bool predicate(T)?])
→ int
-
Returns the number of elements matching the given
predicate or the number of elements when predicate = null.
-
distinct()
→ KtList<T>
-
Returns a list containing only distinct elements from the given collection.
-
distinctBy<K>(K selector(T))
→ KtList<T>
-
Returns a list containing only elements from the given collection
having distinct keys returned by the given
selector function.
-
drop(int n)
→ KtList<T>
-
Returns a list containing all elements except first
n elements.
-
dropWhile(bool predicate(T))
→ KtList<T>
-
Returns a list containing all elements except first elements that satisfy the given
predicate.
-
elementAt(int index)
→ T
-
Returns an element at the given
index or throws an IndexOutOfBoundsException if the index is out of bounds of this collection.
-
elementAtOrElse(int index, T defaultValue(int))
→ 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.
-
elementAtOrNull(int index)
→ T?
-
Returns an element at the given
index or null if the index is out of bounds of this collection.
-
filter(bool predicate(T))
→ KtList<T>
-
Returns a list containing only elements matching the given
predicate.
-
filterIndexed(bool predicate(int index, T))
→ KtList<T>
-
Returns a list containing only elements matching the given
predicate.
@param predicate function that takes the index of an element and the element itself
and returns the result of predicate evaluation on the element.
-
filterIndexedTo<C extends KtMutableCollection>(C destination, bool predicate(int index, T))
→ C
-
Appends all elements matching the given
predicate to the given destination.
@param predicate function that takes the index of an element and the element itself
and returns the result of predicate evaluation on the element.
-
filterIsInstance<R>()
→ KtList<R>
-
Returns a list containing all elements that are instances of specified type parameter R.
-
filterNot(bool predicate(T))
→ KtList<T>
-
Returns a list containing all elements not matching the given
predicate.
-
filterNotNullTo<C extends KtMutableCollection>(C destination)
→ C
-
Appends all elements that are not
null to the given destination.
-
filterNotTo<C extends KtMutableCollection>(C destination, bool predicate(T))
→ C
-
Appends all elements not matching the given
predicate to the given destination.
-
filterTo<C extends KtMutableCollection>(C destination, bool predicate(T))
→ C
-
Appends all elements matching the given
predicate to the given destination.
-
find(bool predicate(T))
→ T?
-
Returns the first element matching the given
predicate, or null if no such element was found.
-
findLast(bool predicate(T))
→ T?
-
Returns the last element matching the given
predicate, or null if no such element was found.
-
first([bool predicate(T)?])
→ T
-
Returns first element.
-
firstNotNullOf<R>(R? transform(T?))
→ R
-
Returns the first non-null value after applying the given
transform
function, throwing a NoSuchElementException exception if there is no
such value.
-
firstNotNullOfOrNull<R>(R? transform(T?))
→ R?
-
Returns the first non-null value after applying the given
transform
function; null will be returned if there is no such value.
-
firstOrNull([bool predicate(T)?])
→ T?
-
Returns the first element (matching
predicate when provided), or null if the collection is empty.
-
flatMap<R>(KtIterable<R> transform(T))
→ KtList<R>
-
Returns a single list of all elements yielded from results of
transform function being invoked on each element of original collection.
-
flatMapIndexed<R>(KtIterable<R> transform(int index, T))
→ KtList<R>
-
Returns a single list of all elements yielded from results of
transform
function being invoked on each element and its index in the original
collection.
-
flatMapIndexedTo<R, C extends KtMutableCollection<R>>(C destination, KtIterable<R> transform(int index, T))
→ C
-
Appends all elements yielded from results of
transform function being
invoked on each element and its index in the original collection, to the
given destination.
-
flatMapTo<R, C extends KtMutableCollection<R>>(C destination, KtIterable<R> transform(T))
→ C
-
Appends all elements yielded from results of
transform function being invoked on each element of original collection, to the given destination.
-
fold<R>(R initial, R operation(R acc, T))
→ R
-
Accumulates value starting with
initial value and applying operation from left to right to current accumulator value and each element.
-
foldIndexed<R>(R initial, R operation(int index, R acc, T))
→ 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.
@param operation function that takes the index of an element, current accumulator value
and the element itself, and calculates the next accumulator value.
-
forEach(void action(T element))
→ void
-
Performs the given
action on each element.
-
forEachIndexed(void action(int index, T element))
→ void
-
Performs the given
action on each element, providing sequential index with the element.
@param action function that takes the index of an element and the element itself
and performs the desired action on the element.
-
groupBy<K>(K keySelector(T))
→ KtMap<K, KtList<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.
-
groupByTo<K, M extends KtMutableMap<K, KtMutableList>>(M destination, K keySelector(T))
→ 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.
-
groupByToTransform<K, V, M extends KtMutableMap<K, KtMutableList<V>>>(M destination, K keySelector(T), V valueTransform(T))
→ 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.
-
groupByTransform<K, V>(K keySelector(T), V valueTransform(T))
→ KtMap<K, KtList<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.
-
indexOf(T element)
→ int
-
Returns first index of
element, or -1 if the collection does not contain element.
-
indexOfFirst(bool predicate(T))
→ int
-
Returns index of the first element matching the given
predicate, or -1 if the collection does not contain such element.
-
indexOfLast(bool predicate(T))
→ int
-
Returns index of the last element matching the given
predicate, or -1 if the collection does not contain such element.
-
intersect(KtIterable<T> other)
→ KtSet<T>
-
Returns a set containing all elements that are contained by both this set and the specified collection.
-
joinToString({String separator = ", ", String prefix = "", String postfix = "", int limit = -1, String truncated = "...", String transform(T)?})
→ String
-
Creates a string from all the elements separated using
separator and using the given prefix and postfix if supplied.
-
last([bool predicate(T)?])
→ T
-
Returns the last element matching the given
predicate.
@throws NoSuchElementException if no such element is found.
-
lastIndexOf(T element)
→ int
-
Returns last index of
element, or -1 if the collection does not contain element.
-
lastOrNull([bool predicate(T)?])
→ T?
-
Returns the last element matching the given
predicate, or null if no such element was found.
-
map<R>(R transform(T))
→ KtList<R>
-
Returns a list containing the results of applying the given
transform function
to each element in the original collection.
-
mapIndexed<R>(R transform(int index, T))
→ KtList<R>
-
Returns a list containing the results of applying the given
transform function
to each element and its index in the original collection.
@param transform function that takes the index of an element and the element itself
and returns the result of the transform applied to the element.
-
mapIndexedNotNull<R>(R? transform(int index, T))
→ KtList<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.
@param transform function that takes the index of an element and the element itself
and returns the result of the transform applied to the element.
-
mapIndexedNotNullTo<R, C extends KtMutableCollection<R>>(C destination, R? transform(int index, T))
→ 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.
@param transform function that takes the index of an element and the element itself
and returns the result of the transform applied to the element.
-
mapIndexedTo<R, C extends KtMutableCollection<R>>(C destination, R transform(int index, T))
→ C
-
Applies the given
transform function to each element and its index in the original collection
and appends the results to the given destination.
@param transform function that takes the index of an element and the element itself
and returns the result of the transform applied to the element.
-
mapNotNull<R>(R? transform(T))
→ KtList<R>
-
Returns a list containing the results of applying the given
transform function
to each element in the original collection.
-
mapNotNullTo<R, C extends KtMutableCollection<R>>(C destination, R? transform(T))
→ 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<R, C extends KtMutableCollection<R>>(C destination, R transform(T))
→ C
-
Applies the given
transform function to each element of the original collection
and appends the results to the given destination.
-
maxBy<R extends Comparable>(R selector(T))
→ T?
-
Returns the first element yielding the largest value of the given function or
null if there are no elements.
-
maxOf<R extends Comparable>(R selector(T))
→ R
-
Returns the largest value among all values produced by selector function applied to each element in the collection.
-
maxWith(Comparator<T> comparator)
→ T?
-
Returns the first element having the largest value according to the provided
comparator or null if there are no elements.
-
minBy<R extends Comparable>(R selector(T))
→ T?
-
Returns the first element yielding the smallest value of the given function or
null if there are no elements.
-
minOf<R extends Comparable>(R selector(T))
→ R
-
Returns the smallest value among all values produced by selector function applied to each element in the array.
-
minus(KtIterable<T> elements)
→ KtList<T>
-
Returns a list containing all elements of the original collection except the elements contained in the given
elements collection.
-
minusElement(T element)
→ KtList<T>
-
Returns a list containing all elements of the original collection without the first occurrence of the given
element.
-
minWith(Comparator<T> comparator)
→ T?
-
Returns the first element having the smallest value according to the provided
comparator or null if there are no elements.
-
none([bool predicate(T)?])
→ bool
-
Returns
true if the collection has no elements or no elements match the given predicate.
-
partition(bool predicate(T))
→ KtPair<KtList<T>, KtList<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(KtIterable<T> elements)
→ KtList<T>
-
Returns a list containing all elements of the original collection and then all elements of the given
elements collection.
-
plusElement(T element)
→ KtList<T>
-
Returns a list containing all elements of the original collection and then the given
element.
-
reduce<S>(S operation(S acc, T))
→ S
-
Accumulates value starting with the first element and applying
operation from left to right to current accumulator value and each element.
-
reduceIndexed<S>(S operation(int index, S acc, T))
→ 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.
@param operation function that takes the index of an element, current accumulator value
and the element itself and calculates the next accumulator value.
-
reduceIndexedOrNull<S>(S operation(int index, S acc, T))
→ 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.
-
reduceOrNull<S>(S operation(S acc, T))
→ S?
-
Accumulates value starting with the first element and applying
operation from left to right to current accumulator value and each element.
-
reversed()
→ KtList<T>
-
Returns a list with elements in reversed order.
-
runningReduce<S>(S operation(S acc, T))
→ KtList<S>
-
Returns a list containing successive accumulation values generated by applying
operation from left to right to each element and current accumulator value that starts with the first element of this collection.
-
runningReduceIndexed<S>(S operation(int index, S acc, T))
→ KtList<S>
-
Returns a list containing successive accumulation values generated by applying
operation from left to right
to each element, its index in the original collection and current accumulator value that starts with the first
element of this collection.
-
shuffled([Random? random])
→ KtList<T>
-
Returns a new list with the elements of this list randomly shuffled.
-
single([bool predicate(T)?])
→ T
-
Returns the single element matching the given
predicate, or throws an exception if the list is empty or has more than one element.
-
singleOrNull([bool predicate(T)?])
→ T?
-
Returns the single element matching the given
predicate, or null if element was not found or more than one element was found.
-
sorted()
→ KtList<T>
-
Returns a list of all elements sorted according to their natural sort order.
-
sortedBy<R extends Comparable>(R selector(T))
→ KtList<T>
-
Returns a list of all elements sorted according to natural sort order of the value returned by specified
selector function.
-
sortedByDescending<R extends Comparable>(R selector(T))
→ KtList<T>
-
Returns a list of all elements sorted descending according to natural sort order of the value returned by specified
selector function.
-
sortedDescending()
→ KtList<T>
-
Returns a list of all elements sorted descending according to their natural sort order.
-
sortedWith(Comparator<T> comparator)
→ KtList<T>
-
Returns a list of all elements sorted according to the specified
comparator.
-
subtract(KtIterable<T> other)
→ KtSet<T>
-
Returns a set containing all elements that are contained by this collection and not contained by the specified collection.
-
sumBy<R extends num>(R selector(T))
→ R
-
Returns the sum of all values produced by
selector function applied to each element in the collection.
-
sumByDouble(double selector(T))
→ double
-
Returns the sum of all values produced by
selector function applied to each element in the collection.
-
take(int n)
→ KtList<T>
-
Returns a list containing first
n elements.
-
takeWhile(bool predicate(T))
→ KtList<T>
-
Returns a list containing first elements satisfying the given
predicate.
-
toCollection<C extends KtMutableCollection>(C destination)
→ C
-
Appends all elements to the given
destination collection.
-
toHashSet()
→ KtMutableSet<T>
-
Returns a HashSet of all elements.
-
toList()
→ KtList<T>
-
Returns a KtList containing all elements.
-
toMutableList()
→ KtMutableList<T>
-
Returns a KtMutableList filled with all elements of this collection.
-
toMutableSet()
→ KtMutableSet<T>
-
Returns a mutable set containing all distinct elements from the given collection.
-
toSet()
→ KtSet<T>
-
Returns a KtSet of all elements.
-
union(KtIterable<T> other)
→ KtSet<T>
-
Returns a set containing all distinct elements from both collections.
-
windowed(int size, {int step = 1, bool partialWindows = false})
→ KtList<KtList<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.
-
windowedTransform<R>(int size, R transform(KtList<T>), {int step = 1, bool partialWindows = false})
→ KtList<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.
-
zip<R>(KtIterable<R> other)
→ KtList<KtPair<T, R>>
-
Returns a list of pairs built from the elements of
this collection and other collection with the same index.
The returned list has length of the shortest collection.
-
zipTransform<R, V>(KtIterable<R> other, V transform(T a, R b))
→ KtList<V>
-
Returns a list of values built from the elements of
this collection and the other collection with the same index
using the provided transform function applied to each pair of elements.
The returned list has length of the shortest collection.
-
zipWithNext()
→ KtList<KtPair<T, T>>
-
Returns a list of pairs of each two adjacent elements in this collection.
-
zipWithNextTransform<R>(R transform(T a, T b))
→ KtList<R>
-
Returns a list containing the results of applying the given
transform function
to an each pair of two adjacent elements in this collection.
Operators
-
operator +(KtIterable<T> elements)
→ KtList<T>
-
Returns a list containing all elements of the original collection and then all elements of the given
elements collection.
-
operator -(KtIterable<T> elements)
→ KtList<T>
-
Returns a list containing all elements of the original collection except the elements contained in the given
elements collection.
