Interface Seq<T>
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- Type Parameters:
T
- Component type
- All Superinterfaces:
Foldable<T>
,java.util.function.Function<java.lang.Integer,T>
,Function1<java.lang.Integer,T>
,Iterable<T>
,java.lang.Iterable<T>
,PartialFunction<java.lang.Integer,T>
,java.io.Serializable
,Traversable<T>
,Value<T>
- All Known Subinterfaces:
IndexedSeq<T>
,LinearSeq<T>
- All Known Implementing Classes:
Array
,CharSeq
,List
,List.Cons
,List.Nil
,Queue
,Stream
,Stream.Cons
,Stream.Empty
,Vector
public interface Seq<T> extends Traversable<T>, PartialFunction<java.lang.Integer,T>, java.io.Serializable
Interface for immutable sequential data structures.Basic operations:
append(Object)
appendAll(Iterable)
insert(int, Object)
insertAll(int, Iterable)
prepend(Object)
prependAll(Iterable)
update(int, Object)
remove(Object)
removeAll(Object)
removeAll(Iterable)
removeAt(int)
removeFirst(Predicate)
removeLast(Predicate)
get(int)
indexOf(Object)
indexOf(Object, int)
lastIndexOf(Object)
lastIndexOf(Object, int)
slice(int, int)
subSequence(int)
subSequence(int, int)
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Field Summary
Fields Modifier and Type Field Description static long
serialVersionUID
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Method Summary
Modifier and Type Method Description Seq<T>
append(T element)
Appends an element to this.Seq<T>
appendAll(java.lang.Iterable<? extends T> elements)
Appends all given elements to this.default T
apply(java.lang.Integer index)
Deprecated.Will be removedjava.util.List<T>
asJava()
Creates an immutableList
view on top of thisSeq
, i.e.Seq<T>
asJava(java.util.function.Consumer<? super java.util.List<T>> action)
Creates an immutableList
view on top of thisSeq
that is passed to the givenaction
.java.util.List<T>
asJavaMutable()
Creates a mutableList
view on top of thisSeq
, i.e.Seq<T>
asJavaMutable(java.util.function.Consumer<? super java.util.List<T>> action)
Creates a mutableList
view on top of thisSeq
that is passed to the givenaction
.PartialFunction<java.lang.Integer,T>
asPartialFunction()
Turns thisSeq
into aPartialFunction
which is defined at a specific index, if thisSeq
contains at least index + 1 elements.<R> Seq<R>
collect(PartialFunction<? super T,? extends R> partialFunction)
Collects all elements that are in the domain of the givenpartialFunction
by mapping the elements to typeR
.Seq<? extends Seq<T>>
combinations()
Returns the union of all combinations from k = 0 to length().Seq<? extends Seq<T>>
combinations(int k)
Returns the k-combination of this traversable, i.e.default boolean
containsSlice(java.lang.Iterable<? extends T> that)
Tests whether this sequence contains a given sequence as a slice.default Iterator<Tuple2<T,T>>
crossProduct()
Calculates the cross product (, i.e.Iterator<? extends Seq<T>>
crossProduct(int power)
Calculates the n-ary cartesian power (or cross product or simply product) of this.default <U> Iterator<Tuple2<T,U>>
crossProduct(java.lang.Iterable<? extends U> that)
Calculates the cross productthis x that
.Seq<T>
distinct()
Returns a new version of this which contains no duplicates.Seq<T>
distinctBy(java.util.Comparator<? super T> comparator)
Returns a new version of this which contains no duplicates.<U> Seq<T>
distinctBy(java.util.function.Function<? super T,? extends U> keyExtractor)
Returns a new version of this which contains no duplicates.Seq<T>
drop(int n)
Drops the first n elements of this or all elements, if this length < n.Seq<T>
dropRight(int n)
Drops the last n elements of this or all elements, if this length < n.Seq<T>
dropRightUntil(java.util.function.Predicate<? super T> predicate)
Drops elements until the predicate holds for the current element, starting from the end.Seq<T>
dropRightWhile(java.util.function.Predicate<? super T> predicate)
Drops elements while the predicate holds for the current element, starting from the end.Seq<T>
dropUntil(java.util.function.Predicate<? super T> predicate)
Drops elements until the predicate holds for the current element.Seq<T>
dropWhile(java.util.function.Predicate<? super T> predicate)
Drops elements while the predicate holds for the current element.default boolean
endsWith(Seq<? extends T> that)
Tests whether this sequence ends with the given sequence.Seq<T>
filter(java.util.function.Predicate<? super T> predicate)
Returns a new traversable consisting of all elements which satisfy the given predicate.Seq<T>
filterNot(java.util.function.Predicate<? super T> predicate)
Returns a new traversable consisting of all elements which do not satisfy the given predicate.<U> Seq<U>
flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends U>> mapper)
FlatMaps this Traversable.default <U> U
foldRight(U zero, java.util.function.BiFunction<? super T,? super U,? extends U> f)
Folds this elements from the right, starting withzero
and successively callingcombine
.T
get(int index)
Returns the element at the specified index.<C> Map<C,? extends Seq<T>>
groupBy(java.util.function.Function<? super T,? extends C> classifier)
Groups this elements by classifying the elements.Iterator<? extends Seq<T>>
grouped(int size)
Groups thisTraversable
into fixed size blocks.default int
indexOf(T element)
Returns the index of the first occurrence of the given element or -1 if this does not contain the given element.int
indexOf(T element, int from)
Returns the index of the first occurrence of the given element after or at some start index or -1 if this does not contain the given element.default Option<java.lang.Integer>
indexOfOption(T element)
Returns the index of the first occurrence of the given element as anOption
default Option<java.lang.Integer>
indexOfOption(T element, int from)
Returns the index of the first occurrence of the given element, after or at some start index as anOption
default int
indexOfSlice(java.lang.Iterable<? extends T> that)
Finds first index where this sequence contains a given sequence as a slice.int
indexOfSlice(java.lang.Iterable<? extends T> that, int from)
Finds first index after or at a start index where this sequence contains a given sequence as a slice.default Option<java.lang.Integer>
indexOfSliceOption(java.lang.Iterable<? extends T> that)
Finds first index where this sequence contains a given sequence as anOption
of a slice.default Option<java.lang.Integer>
indexOfSliceOption(java.lang.Iterable<? extends T> that, int from)
Finds first index after or at a start index where this sequence contains a given sequence as anOption
of a slice.default int
indexWhere(java.util.function.Predicate<? super T> predicate)
Finds index of first element satisfying some predicate.int
indexWhere(java.util.function.Predicate<? super T> predicate, int from)
Finds index of the first element satisfying some predicate after or at some start index.default Option<java.lang.Integer>
indexWhereOption(java.util.function.Predicate<? super T> predicate)
Finds index of first element satisfying some predicate as anOption
.default Option<java.lang.Integer>
indexWhereOption(java.util.function.Predicate<? super T> predicate, int from)
Finds index of the first element satisfying some predicate after or at some start index as anOption
.Seq<T>
init()
Dual of Traversable.tail(), returning all elements except the last.Option<? extends Seq<T>>
initOption()
Dual of Traversable.tailOption(), returning all elements except the last asOption
.Seq<T>
insert(int index, T element)
Inserts the given element at the specified index.Seq<T>
insertAll(int index, java.lang.Iterable<? extends T> elements)
Inserts the given elements at the specified index.Seq<T>
intersperse(T element)
Inserts an element between all elements of this Traversable.default boolean
isSequential()
Checks if the elements of this Traversable appear in encounter order.default Iterator<T>
iterator(int index)
Returns an iterator of this elements starting at the given index.default int
lastIndexOf(T element)
Returns the index of the last occurrence of the given element or -1 if this does not contain the given element.int
lastIndexOf(T element, int end)
Returns the index of the last occurrence of the given element before or at a given end index or -1 if this does not contain the given element.default Option<java.lang.Integer>
lastIndexOfOption(T element)
Returns the index of the last occurrence of the given element as anOption
.default Option<java.lang.Integer>
lastIndexOfOption(T element, int end)
Returns the index of the last occurrence of the given element before or at a given end index as anOption
.default int
lastIndexOfSlice(java.lang.Iterable<? extends T> that)
Finds last index where this sequence contains a given sequence as a slice.int
lastIndexOfSlice(java.lang.Iterable<? extends T> that, int end)
Finds last index before or at a given end index where this sequence contains a given sequence as a slice.default Option<java.lang.Integer>
lastIndexOfSliceOption(java.lang.Iterable<? extends T> that)
Finds last index where this sequence contains a given sequence as a slice as anOption
.default Option<java.lang.Integer>
lastIndexOfSliceOption(java.lang.Iterable<? extends T> that, int end)
Finds last index before or at a given end index where this sequence contains a given sequence as a slice as anOption
.default int
lastIndexWhere(java.util.function.Predicate<? super T> predicate)
Finds index of last element satisfying some predicate.int
lastIndexWhere(java.util.function.Predicate<? super T> predicate, int end)
Finds index of last element satisfying some predicate before or at given end index.default Option<java.lang.Integer>
lastIndexWhereOption(java.util.function.Predicate<? super T> predicate)
Finds index of last element satisfying some predicate as anOption
.default Option<java.lang.Integer>
lastIndexWhereOption(java.util.function.Predicate<? super T> predicate, int end)
Finds index of last element satisfying some predicate before or at given end index as anOption
.Seq<T>
leftPadTo(int length, T element)
A copy of this sequence with an element prepended until a given target length is reached.default Function1<java.lang.Integer,Option<T>>
lift()
Deprecated.Will be removed<U> Seq<U>
map(java.util.function.Function<? super T,? extends U> mapper)
Maps the elements of thisTraversable
to elements of a new type preserving their order, if any.static <T> Seq<T>
narrow(Seq<? extends T> seq)
Narrows a widenedSeq<? extends T>
toSeq<T>
by performing a type-safe cast.Seq<T>
orElse(java.lang.Iterable<? extends T> other)
Returns thisTraversable
if it is nonempty, otherwise return the alternative.Seq<T>
orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
Returns thisTraversable
if it is nonempty, otherwise return the result of evaluating supplier.Seq<T>
padTo(int length, T element)
A copy of this sequence with an element appended until a given target length is reached.Tuple2<? extends Seq<T>,? extends Seq<T>>
partition(java.util.function.Predicate<? super T> predicate)
Creates a partition of thisTraversable
by splitting this elements in two in distinct traversables according to a predicate.Seq<T>
patch(int from, java.lang.Iterable<? extends T> that, int replaced)
Produces a new list where a slice of elements in this list is replaced by another sequence.Seq<T>
peek(java.util.function.Consumer<? super T> action)
Performs the givenaction
on the first element if this is an eager implementation.Seq<? extends Seq<T>>
permutations()
Computes all unique permutations.default int
prefixLength(java.util.function.Predicate<? super T> predicate)
Returns the length of the longest prefix whose elements all satisfy some predicate.Seq<T>
prepend(T element)
Prepends an element to this.Seq<T>
prependAll(java.lang.Iterable<? extends T> elements)
Prepends all given elements to this.Seq<T>
reject(java.util.function.Predicate<? super T> predicate)
Deprecated.Seq<T>
remove(T element)
Removes the first occurrence of the given element.Seq<T>
removeAll(java.lang.Iterable<? extends T> elements)
Removes all occurrences of the given elements.Seq<T>
removeAll(java.util.function.Predicate<? super T> predicate)
Deprecated.Please usereject(Predicate)
Seq<T>
removeAll(T element)
Removes all occurrences of the given element.Seq<T>
removeAt(int index)
Removes the element at the specified position in this sequence.Seq<T>
removeFirst(java.util.function.Predicate<T> predicate)
Removes the first occurrence that satisfy predicateSeq<T>
removeLast(java.util.function.Predicate<T> predicate)
Removes the last occurrence that satisfy predicateSeq<T>
replace(T currentElement, T newElement)
Replaces the first occurrence (if exists) of the given currentElement with newElement.Seq<T>
replaceAll(T currentElement, T newElement)
Replaces all occurrences of the given currentElement with newElement.Seq<T>
retainAll(java.lang.Iterable<? extends T> elements)
Keeps all occurrences of the given elements from this.Seq<T>
reverse()
Reverses the order of elements.Iterator<T>
reverseIterator()
An iterator yielding elements in reversed order.Seq<T>
rotateLeft(int n)
Circular rotates the elements by the specified distance to the left direction.Seq<T>
rotateRight(int n)
Circular rotates the elements by the specified distance to the right direction.Seq<T>
scan(T zero, java.util.function.BiFunction<? super T,? super T,? extends T> operation)
Computes a prefix scan of the elements of the collection.<U> Seq<U>
scanLeft(U zero, java.util.function.BiFunction<? super U,? super T,? extends U> operation)
Produces a collection containing cumulative results of applying the operator going left to right.<U> Seq<U>
scanRight(U zero, java.util.function.BiFunction<? super T,? super U,? extends U> operation)
Produces a collection containing cumulative results of applying the operator going right to left.int
search(T element)
Searches this sequence for a specific element.int
search(T element, java.util.Comparator<? super T> comparator)
Searches this sequence for a specific element.int
segmentLength(java.util.function.Predicate<? super T> predicate, int from)
Computes length of longest segment whose elements all satisfy some predicate.Seq<T>
shuffle()
Randomize the order of the elements in the current sequence.Seq<T>
shuffle(java.util.Random random)
Randomize the order of the elements in the current sequence using the given source of randomness.Seq<T>
slice(int beginIndex, int endIndex)
Returns a Seq that is a slice of this.Iterator<? extends Seq<T>>
slideBy(java.util.function.Function<? super T,?> classifier)
Slides a non-overlapping window of a variable size over thisTraversable
.Iterator<? extends Seq<T>>
sliding(int size)
Slides a window of a specificsize
and step size 1 over thisTraversable
by callingTraversable.sliding(int, int)
.Iterator<? extends Seq<T>>
sliding(int size, int step)
Slides a window of a specificsize
andstep
size over thisTraversable
.<U> Seq<T>
sortBy(java.util.Comparator<? super U> comparator, java.util.function.Function<? super T,? extends U> mapper)
Sorts this elements by comparing the elements in a different domain, using the givenmapper
.<U extends java.lang.Comparable<? super U>>
Seq<T>sortBy(java.util.function.Function<? super T,? extends U> mapper)
Sorts this elements by comparing the elements in a different domain, using the givenmapper
.Seq<T>
sorted()
Sorts this elements according to their natural order.Seq<T>
sorted(java.util.Comparator<? super T> comparator)
Sorts this elements according to the providedComparator
.Tuple2<? extends Seq<T>,? extends Seq<T>>
span(java.util.function.Predicate<? super T> predicate)
Returns a tuple where the first element is the longest prefix of elements that satisfy the givenpredicate
and the second element is the remainder.Tuple2<? extends Seq<T>,? extends Seq<T>>
splitAt(int n)
Splits a Seq at the specified index.Tuple2<? extends Seq<T>,? extends Seq<T>>
splitAt(java.util.function.Predicate<? super T> predicate)
Splits a sequence at the first element which satisfies thePredicate
, e.g.Tuple2<? extends Seq<T>,? extends Seq<T>>
splitAtInclusive(java.util.function.Predicate<? super T> predicate)
Splits a sequence at the first element which satisfies thePredicate
, e.g.default boolean
startsWith(java.lang.Iterable<? extends T> that)
Tests whether this list starts with the given sequence.default boolean
startsWith(java.lang.Iterable<? extends T> that, int offset)
Tests whether this list contains the given sequence at a given index.Seq<T>
subSequence(int beginIndex)
Returns a Seq that is a subsequence of this.Seq<T>
subSequence(int beginIndex, int endIndex)
Returns a Seq that is a subsequence of this.Seq<T>
tail()
Drops the first element of a non-empty Traversable.Option<? extends Seq<T>>
tailOption()
Drops the first element of a non-empty Traversable and returns anOption
.Seq<T>
take(int n)
Takes the first n elements of this or all elements, if this length < n.Seq<T>
takeRight(int n)
Takes the last n elements of this or all elements, if this length < n.Seq<T>
takeRightUntil(java.util.function.Predicate<? super T> predicate)
Takes elements until the predicate holds for the current element, starting from the end.Seq<T>
takeRightWhile(java.util.function.Predicate<? super T> predicate)
Takes elements while the predicate holds for the current element, starting from the end.Seq<T>
takeUntil(java.util.function.Predicate<? super T> predicate)
Takes elements until the predicate holds for the current element.Seq<T>
takeWhile(java.util.function.Predicate<? super T> predicate)
Takes elements while the predicate holds for the current element.<T1,T2>
Tuple2<? extends Seq<T1>,? extends Seq<T2>>unzip(java.util.function.Function<? super T,Tuple2<? extends T1,? extends T2>> unzipper)
Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.<T1,T2,T3>
Tuple3<? extends Seq<T1>,? extends Seq<T2>,? extends Seq<T3>>unzip3(java.util.function.Function<? super T,Tuple3<? extends T1,? extends T2,? extends T3>> unzipper)
Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.Seq<T>
update(int index, java.util.function.Function<? super T,? extends T> updater)
Updates the given element at the specified index using the specified function.Seq<T>
update(int index, T element)
Updates the given element at the specified index.default Function1<java.lang.Integer,T>
withDefault(java.util.function.Function<? super java.lang.Integer,? extends T> defaultFunction)
Deprecated.Will be removeddefault Function1<java.lang.Integer,T>
withDefaultValue(T defaultValue)
Deprecated.Will be removed<U> Seq<Tuple2<T,U>>
zip(java.lang.Iterable<? extends U> that)
Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs.<U> Seq<Tuple2<T,U>>
zipAll(java.lang.Iterable<? extends U> that, T thisElem, U thatElem)
Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs.<U,R>
Seq<R>zipWith(java.lang.Iterable<? extends U> that, java.util.function.BiFunction<? super T,? super U,? extends R> mapper)
Returns a traversable formed from this traversable and another Iterable collection by mapping elements.Seq<Tuple2<T,java.lang.Integer>>
zipWithIndex()
Zips this traversable with its indices.<U> Seq<U>
zipWithIndex(java.util.function.BiFunction<? super T,? super java.lang.Integer,? extends U> mapper)
Returns a traversable formed from this traversable and another Iterable collection by mapping elements.-
Methods inherited from interface io.vavr.Function1
andThen, arity, compose, curried, isMemoized, memoized, partial, reversed, tupled
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Methods inherited from interface io.vavr.PartialFunction
isDefinedAt
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Methods inherited from interface io.vavr.collection.Traversable
arrangeBy, average, containsAll, count, equals, existsUnique, find, findLast, fold, foldLeft, forEachWithIndex, get, hasDefiniteSize, hashCode, head, headOption, isDistinct, isEmpty, isOrdered, isSingleValued, isTraversableAgain, iterator, last, lastOption, length, max, maxBy, maxBy, min, minBy, minBy, mkCharSeq, mkCharSeq, mkCharSeq, mkString, mkString, mkString, nonEmpty, product, reduce, reduceLeft, reduceLeftOption, reduceOption, reduceRight, reduceRightOption, single, singleOption, size, spliterator, sum
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Methods inherited from interface io.vavr.Value
collect, collect, contains, corresponds, eq, exists, forAll, forEach, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, getOrNull, isAsync, isLazy, out, out, stderr, stdout, stringPrefix, toArray, toCharSeq, toCompletableFuture, toEither, toEither, toInvalid, toInvalid, toJavaArray, toJavaArray, toJavaArray, toJavaCollection, toJavaList, toJavaList, toJavaMap, toJavaMap, toJavaMap, toJavaOptional, toJavaParallelStream, toJavaSet, toJavaSet, toJavaStream, toLeft, toLeft, toLinkedMap, toLinkedMap, toLinkedSet, toList, toMap, toMap, toOption, toPriorityQueue, toPriorityQueue, toQueue, toRight, toRight, toSet, toSortedMap, toSortedMap, toSortedMap, toSortedMap, toSortedSet, toSortedSet, toStream, toString, toTree, toTree, toTry, toTry, toValid, toValid, toValidation, toValidation, toVector
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Field Detail
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serialVersionUID
static final long serialVersionUID
- See Also:
- Constant Field Values
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Method Detail
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narrow
static <T> Seq<T> narrow(Seq<? extends T> seq)
Narrows a widenedSeq<? extends T>
toSeq<T>
by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.- Type Parameters:
T
- Component type of theSeq
.- Parameters:
seq
- ASeq
.- Returns:
- the given
seq
instance as narrowed typeSeq<T>
.
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append
Seq<T> append(T element)
Appends an element to this.- Parameters:
element
- An element- Returns:
- A new Seq containing the given element appended to this elements
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appendAll
Seq<T> appendAll(java.lang.Iterable<? extends T> elements)
Appends all given elements to this.- Parameters:
elements
- An Iterable of elements- Returns:
- A new Seq containing the given elements appended to this elements
- Throws:
java.lang.NullPointerException
- ifelements
is null
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apply
@Deprecated default T apply(java.lang.Integer index)
Deprecated.Will be removedASeq
is a partial function which returns the element at the specified index by calling get(int).- Specified by:
apply
in interfacejava.util.function.Function<java.lang.Integer,T>
- Specified by:
apply
in interfaceFunction1<java.lang.Integer,T>
- Specified by:
apply
in interfacePartialFunction<java.lang.Integer,T>
- Parameters:
index
- an index- Returns:
- the element at the given index
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
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asJava
@GwtIncompatible java.util.List<T> asJava()
Creates an immutableList
view on top of thisSeq
, i.e. calling mutators will result inUnsupportedOperationException
at runtime.The difference to conversion methods
toJava*()
is that- A view is created in O(1) (constant time) whereas conversion takes O(n) (linear time), with n = collection size.
- The operations on a view have the same performance characteristics than the underlying persistent Vavr collection whereas the performance characteristics of a converted collection are those of the Java standard collections.
java.util.List
view throwsUnsupportedOperationException
before checking method arguments. Java does handle this case inconsistently.- Returns:
- A new immutable
Collection
view on thisTraversable
.
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asJava
@GwtIncompatible Seq<T> asJava(java.util.function.Consumer<? super java.util.List<T>> action)
Creates an immutableList
view on top of thisSeq
that is passed to the givenaction
.- Parameters:
action
- A side-effecting unit of work that operates on an immutablejava.util.List
view.- Returns:
- this instance
- See Also:
asJava()
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asJavaMutable
@GwtIncompatible java.util.List<T> asJavaMutable()
Creates a mutableList
view on top of thisSeq
, i.e. all mutator methods of theList
are implemented.- Returns:
- A new mutable
Collection
view on thisTraversable
. - See Also:
asJava()
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asJavaMutable
@GwtIncompatible Seq<T> asJavaMutable(java.util.function.Consumer<? super java.util.List<T>> action)
Creates a mutableList
view on top of thisSeq
that is passed to the givenaction
.- Parameters:
action
- A side-effecting unit of work that operates on a mutablejava.util.List
view.- Returns:
- this instance, if only read operations are performed on the
java.util.List
view or a new instance of this type, if write operations are performed on thejava.util.List
view. - See Also:
asJavaMutable()
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asPartialFunction
PartialFunction<java.lang.Integer,T> asPartialFunction() throws java.lang.IndexOutOfBoundsException
Turns thisSeq
into aPartialFunction
which is defined at a specific index, if thisSeq
contains at least index + 1 elements. When applied to a defined index, the partial function will return the value of thisSeq
at the specified index.- Returns:
- a new
PartialFunction
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
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collect
<R> Seq<R> collect(PartialFunction<? super T,? extends R> partialFunction)
Description copied from interface:Traversable
Collects all elements that are in the domain of the givenpartialFunction
by mapping the elements to typeR
.More specifically, for each of this elements in iteration order first it is checked
If the elements makes it through that filter, the mapped instance is added to the result collectionpartialFunction.isDefinedAt(element)
Note:If thisR newElement = partialFunction.apply(element)
Traversable
is ordered (i.e. extendsOrdered
, the caller ofcollect
has to ensure that the elements are comparable (i.e. extendComparable
).- Specified by:
collect
in interfaceTraversable<T>
- Type Parameters:
R
- The new element type- Parameters:
partialFunction
- A function that is not necessarily defined of all elements of this traversable.- Returns:
- A new
Traversable
instance containing elements of typeR
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combinations
Seq<? extends Seq<T>> combinations()
Returns the union of all combinations from k = 0 to length().Examples:
[].combinations() = [[]] [1,2,3].combinations() = [ [], // k = 0 [1], [2], [3], // k = 1 [1,2], [1,3], [2,3], // k = 2 [1,2,3] // k = 3 ]
- Returns:
- the combinations of this
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combinations
Seq<? extends Seq<T>> combinations(int k)
Returns the k-combination of this traversable, i.e. all subset of this of k distinct elements.- Parameters:
k
- Size of subsets- Returns:
- the k-combination of this elements
- See Also:
- Combination
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containsSlice
default boolean containsSlice(java.lang.Iterable<? extends T> that)
Tests whether this sequence contains a given sequence as a slice.Note: may not terminate for infinite sequences.
- Parameters:
that
- the sequence to test- Returns:
- true if this sequence contains a slice with the same elements as that, otherwise false.
- Throws:
java.lang.NullPointerException
- ifthat
is null.
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crossProduct
default Iterator<Tuple2<T,T>> crossProduct()
Calculates the cross product (, i.e. square) ofthis x this
.Example:
// = List of Tuples (1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3) List.of(1, 2, 3).crossProduct();
- Returns:
- a new Iterator containing the square of
this
-
crossProduct
Iterator<? extends Seq<T>> crossProduct(int power)
Calculates the n-ary cartesian power (or cross product or simply product) of this.Example:
// = ((A,A), (A,B), (A,C), ..., (B,A), (B,B), ..., (Z,Y), (Z,Z)) CharSeq.rangeClosed('A', 'Z').crossProduct(2);
Cartesian power of negative value will return empty iterator.
Example:
// = () CharSeq.rangeClosed('A', 'Z').crossProduct(-1);
- Parameters:
power
- the number of cartesian multiplications- Returns:
- A new Iterator representing the n-ary cartesian power of this
-
crossProduct
default <U> Iterator<Tuple2<T,U>> crossProduct(java.lang.Iterable<? extends U> that)
Calculates the cross productthis x that
.Example:
// = List of Tuples (1, 'a'), (1, 'b'), (2, 'a'), (2, 'b'), (3, 'a'), (3, 'b') List.of(1, 2, 3).crossProduct(List.of('a', 'b');
- Type Parameters:
U
- Component type- Parameters:
that
- Another iterable- Returns:
- a new Iterator containing the cross product
this x that
- Throws:
java.lang.NullPointerException
- if that is null
-
endsWith
default boolean endsWith(Seq<? extends T> that)
Tests whether this sequence ends with the given sequence.Note: If the both the receiver object this and the argument that are infinite sequences this method may not terminate.
- Parameters:
that
- the sequence to test- Returns:
- true if this sequence has that as a suffix, false otherwise.
-
get
T get(int index)
Returns the element at the specified index.- Parameters:
index
- an index- Returns:
- the element at the given index
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
-
indexOf
default int indexOf(T element)
Returns the index of the first occurrence of the given element or -1 if this does not contain the given element.- Parameters:
element
- an element- Returns:
- the index of the first occurrence of the given element
-
indexOfOption
default Option<java.lang.Integer> indexOfOption(T element)
Returns the index of the first occurrence of the given element as anOption
- Parameters:
element
- an element- Returns:
Some(index)
orNone
if not found.
-
indexOf
int indexOf(T element, int from)
Returns the index of the first occurrence of the given element after or at some start index or -1 if this does not contain the given element.- Parameters:
element
- an elementfrom
- start index- Returns:
- the index of the first occurrence of the given element
-
indexOfOption
default Option<java.lang.Integer> indexOfOption(T element, int from)
Returns the index of the first occurrence of the given element, after or at some start index as anOption
- Parameters:
element
- an elementfrom
- start index- Returns:
Some(index)
orNone
if not found.
-
indexOfSlice
default int indexOfSlice(java.lang.Iterable<? extends T> that)
Finds first index where this sequence contains a given sequence as a slice.Note: may not terminate for infinite sequences.
- Parameters:
that
- the sequence to test- Returns:
- the first index such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such slice exists.
- Throws:
java.lang.NullPointerException
- ifthat
is null.
-
indexOfSliceOption
default Option<java.lang.Integer> indexOfSliceOption(java.lang.Iterable<? extends T> that)
Finds first index where this sequence contains a given sequence as anOption
of a slice.Note: may not terminate for infinite sequences.
- Parameters:
that
- the sequence to test- Returns:
Some(index)
orNone
if not found.
-
indexOfSlice
int indexOfSlice(java.lang.Iterable<? extends T> that, int from)
Finds first index after or at a start index where this sequence contains a given sequence as a slice. Note: may not terminate for infinite sequences.- Parameters:
that
- the sequence to testfrom
- the start index- Returns:
- the first index >= from such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such slice exists.
- Throws:
java.lang.NullPointerException
- ifthat
is null.
-
indexOfSliceOption
default Option<java.lang.Integer> indexOfSliceOption(java.lang.Iterable<? extends T> that, int from)
Finds first index after or at a start index where this sequence contains a given sequence as anOption
of a slice. Note: may not terminate for infinite sequences.- Parameters:
that
- the sequence to testfrom
- the start index- Returns:
Some(index)
orNone
if not found.
-
indexWhere
default int indexWhere(java.util.function.Predicate<? super T> predicate)
Finds index of first element satisfying some predicate.- Parameters:
predicate
- the predicate used to test elements.- Returns:
- the index of the first element of this Seq that satisfies the given
predicate
, or-1
, if none exists.
-
indexWhereOption
default Option<java.lang.Integer> indexWhereOption(java.util.function.Predicate<? super T> predicate)
Finds index of first element satisfying some predicate as anOption
.- Parameters:
predicate
- the predicate used to test elements.- Returns:
Some(index)
orNone
if not found.
-
indexWhere
int indexWhere(java.util.function.Predicate<? super T> predicate, int from)
Finds index of the first element satisfying some predicate after or at some start index.- Parameters:
predicate
- the predicate used to test elements.from
- the start index- Returns:
- the index
>= from
of the first element of this Seq that satisfies the givenpredicate
, or-1
, if none exists.
-
indexWhereOption
default Option<java.lang.Integer> indexWhereOption(java.util.function.Predicate<? super T> predicate, int from)
Finds index of the first element satisfying some predicate after or at some start index as anOption
.- Parameters:
predicate
- the predicate used to test elements.from
- the start index- Returns:
Some(index)
orNone
if not found.
-
insert
Seq<T> insert(int index, T element)
Inserts the given element at the specified index.- Parameters:
index
- an indexelement
- an element- Returns:
- a new Seq, where the given element is inserted into this at the given index
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
-
insertAll
Seq<T> insertAll(int index, java.lang.Iterable<? extends T> elements)
Inserts the given elements at the specified index.- Parameters:
index
- an indexelements
- An Iterable of elements- Returns:
- a new Seq, where the given elements are inserted into this at the given index
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
-
intersperse
Seq<T> intersperse(T element)
Inserts an element between all elements of this Traversable.- Parameters:
element
- An element.- Returns:
- an interspersed version of this
-
iterator
default Iterator<T> iterator(int index)
Returns an iterator of this elements starting at the given index. The result is equivalent tothis.subSequence(index).iterator()
.- Parameters:
index
- an index- Returns:
- a new Iterator, starting with the element at the given index or the empty Iterator, if index = length()
- Throws:
java.lang.IndexOutOfBoundsException
- if index < 0 or index > length()
-
lastIndexOf
default int lastIndexOf(T element)
Returns the index of the last occurrence of the given element or -1 if this does not contain the given element.- Parameters:
element
- an element- Returns:
- the index of the last occurrence of the given element
-
lastIndexOfOption
default Option<java.lang.Integer> lastIndexOfOption(T element)
Returns the index of the last occurrence of the given element as anOption
.- Parameters:
element
- an element- Returns:
Some(index)
orNone
if not found.
-
lastIndexWhere
default int lastIndexWhere(java.util.function.Predicate<? super T> predicate)
Finds index of last element satisfying some predicate.- Parameters:
predicate
- the predicate used to test elements.- Returns:
- the index of the last element of this Seq that satisfies the given
predicate
, or-1
, if none exists.
-
lastIndexWhereOption
default Option<java.lang.Integer> lastIndexWhereOption(java.util.function.Predicate<? super T> predicate)
Finds index of last element satisfying some predicate as anOption
.- Parameters:
predicate
- the predicate used to test elements.- Returns:
Some(index)
orNone
if not found.
-
lastIndexWhere
int lastIndexWhere(java.util.function.Predicate<? super T> predicate, int end)
Finds index of last element satisfying some predicate before or at given end index.- Parameters:
predicate
- the predicate used to test elements.end
- the maximum index of the search- Returns:
- the index
<= end
of the last element of this Seq that satisfies the givenpredicate
, or-1
, if none exists.
-
lastIndexWhereOption
default Option<java.lang.Integer> lastIndexWhereOption(java.util.function.Predicate<? super T> predicate, int end)
Finds index of last element satisfying some predicate before or at given end index as anOption
.- Parameters:
predicate
- the predicate used to test elements.end
- the maximum index of the search- Returns:
Some(index)
orNone
if not found.
-
lift
@Deprecated default Function1<java.lang.Integer,Option<T>> lift()
Deprecated.Will be removedTurns this sequence into a plain function returning an Option result.- Specified by:
lift
in interfacePartialFunction<java.lang.Integer,T>
- Returns:
- a function that takes an index i and returns the value of this sequence in a Some if the index is within bounds, otherwise a None.
-
lastIndexOf
int lastIndexOf(T element, int end)
Returns the index of the last occurrence of the given element before or at a given end index or -1 if this does not contain the given element.- Parameters:
element
- an elementend
- the end index- Returns:
- the index of the last occurrence of the given element
-
lastIndexOfOption
default Option<java.lang.Integer> lastIndexOfOption(T element, int end)
Returns the index of the last occurrence of the given element before or at a given end index as anOption
.- Parameters:
element
- an elementend
- the end index- Returns:
Some(index)
orNone
if not found.
-
lastIndexOfSlice
default int lastIndexOfSlice(java.lang.Iterable<? extends T> that)
Finds last index where this sequence contains a given sequence as a slice.Note: will not terminate for infinite sequences.
- Parameters:
that
- the sequence to test- Returns:
- the last index such that the elements of this sequence starting a this index match the elements of sequence that, or -1 of no such slice exists.
- Throws:
java.lang.NullPointerException
- ifthat
is null.
-
lastIndexOfSliceOption
default Option<java.lang.Integer> lastIndexOfSliceOption(java.lang.Iterable<? extends T> that)
Finds last index where this sequence contains a given sequence as a slice as anOption
.- Parameters:
that
- the sequence to test- Returns:
Some(index)
orNone
if not found.
-
lastIndexOfSlice
int lastIndexOfSlice(java.lang.Iterable<? extends T> that, int end)
Finds last index before or at a given end index where this sequence contains a given sequence as a slice.- Parameters:
that
- the sequence to testend
- the end index- Returns:
- the last index <= end such that the elements of this sequence starting at this index match the elements of sequence that, or -1 of no such slice exists.
- Throws:
java.lang.NullPointerException
- ifthat
is null.
-
lastIndexOfSliceOption
default Option<java.lang.Integer> lastIndexOfSliceOption(java.lang.Iterable<? extends T> that, int end)
Finds last index before or at a given end index where this sequence contains a given sequence as a slice as anOption
.- Parameters:
that
- the sequence to testend
- the end index- Returns:
Some(index)
orNone
if not found.
-
padTo
Seq<T> padTo(int length, T element)
A copy of this sequence with an element appended until a given target length is reached.Note: lazily-evaluated Seq implementations need to process all elements in order to gather the overall length.
- Parameters:
length
- the target lengthelement
- the padding element- Returns:
- a new sequence consisting of all elements of this sequence followed by the minimal number
of occurrences of
element
so that the resulting sequence has a length of at leastlength
.
-
leftPadTo
Seq<T> leftPadTo(int length, T element)
A copy of this sequence with an element prepended until a given target length is reached.Note: lazily-evaluated Seq implementations need to process all elements in order to gather the overall length.
- Parameters:
length
- the target lengthelement
- the padding element- Returns:
- a new sequence consisting of all elements of this sequence prepended by the minimal number
of occurrences of
element
so that the resulting sequence has a length of at leastlength
.
-
patch
Seq<T> patch(int from, java.lang.Iterable<? extends T> that, int replaced)
Produces a new list where a slice of elements in this list is replaced by another sequence.- Parameters:
from
- the index of the first replaced elementthat
- sequence for replacementreplaced
- the number of elements to drop in the original list- Returns:
- a new sequence.
-
permutations
Seq<? extends Seq<T>> permutations()
Computes all unique permutations.Example:
[].permutations() = [] [1,2,3].permutations() = [ [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1] ]
- Returns:
- this unique permutations
-
prefixLength
default int prefixLength(java.util.function.Predicate<? super T> predicate)
Returns the length of the longest prefix whose elements all satisfy some predicate. Note: may not terminate for infinite-sized collections.- Parameters:
predicate
- the predicate used to test elements.- Returns:
- the length of the longest prefix of this general sequence such that every element of the segment satisfies the predicate p.
-
prepend
Seq<T> prepend(T element)
Prepends an element to this.- Parameters:
element
- An element- Returns:
- A new Seq containing the given element prepended to this elements
-
prependAll
Seq<T> prependAll(java.lang.Iterable<? extends T> elements)
Prepends all given elements to this.- Parameters:
elements
- An Iterable of elements- Returns:
- A new Seq containing the given elements prepended to this elements
-
remove
Seq<T> remove(T element)
Removes the first occurrence of the given element.- Parameters:
element
- An element to be removed from this Seq.- Returns:
- a Seq containing all elements of this without the first occurrence of the given element.
-
removeAll
Seq<T> removeAll(T element)
Removes all occurrences of the given element.- Parameters:
element
- An element to be removed from this Seq.- Returns:
- a Seq containing all elements of this but not the given element.
-
removeAll
Seq<T> removeAll(java.lang.Iterable<? extends T> elements)
Removes all occurrences of the given elements.- Parameters:
elements
- Elements to be removed from this Seq.- Returns:
- a Seq containing all elements of this but none of the given elements.
- Throws:
java.lang.NullPointerException
- ifelements
is null
-
removeAll
@Deprecated Seq<T> removeAll(java.util.function.Predicate<? super T> predicate)
Deprecated.Please usereject(Predicate)
Returns a new Seq consisting of all elements which do not satisfy the given predicate.- Parameters:
predicate
- the predicate used to test elements- Returns:
- a new Seq
- Throws:
java.lang.NullPointerException
- ifpredicate
is null
-
removeAt
Seq<T> removeAt(int index)
Removes the element at the specified position in this sequence. Shifts any subsequent elements to the left (subtracts one from their indices).- Parameters:
index
- position of element to remove- Returns:
- a sequence containing all elements of this without the element at the specified position.
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
-
removeFirst
Seq<T> removeFirst(java.util.function.Predicate<T> predicate)
Removes the first occurrence that satisfy predicate- Parameters:
predicate
- an predicate- Returns:
- a new Seq
-
removeLast
Seq<T> removeLast(java.util.function.Predicate<T> predicate)
Removes the last occurrence that satisfy predicate- Parameters:
predicate
- an predicate- Returns:
- a new Seq
-
reverseIterator
Iterator<T> reverseIterator()
An iterator yielding elements in reversed order.Note:
xs.reverseIterator()
is the same asxs.reverse().iterator()
but might be more efficient.- Returns:
- an iterator yielding the elements of this Seq in reversed order
-
rotateLeft
Seq<T> rotateLeft(int n)
Circular rotates the elements by the specified distance to the left direction.// = List(3, 4, 5, 1, 2) List.of(1, 2, 3, 4, 5).rotateLeft(2);
- Parameters:
n
- distance of left rotation- Returns:
- the rotated elements.
-
rotateRight
Seq<T> rotateRight(int n)
Circular rotates the elements by the specified distance to the right direction.// = List(4, 5, 1, 2, 3) List.of(1, 2, 3, 4, 5).rotateRight(2);
- Parameters:
n
- distance of right rotation- Returns:
- the rotated elements.
-
segmentLength
int segmentLength(java.util.function.Predicate<? super T> predicate, int from)
Computes length of longest segment whose elements all satisfy some predicate.Note: may not terminate for infinite sequences.
- Parameters:
predicate
- the predicate used to test elements.from
- the index where the search starts.- Returns:
- the length of the longest segment of this sequence starting from index from such that every element of the segment satisfies the predicate p.
-
shuffle
Seq<T> shuffle()
Randomize the order of the elements in the current sequence.- Returns:
- a sequence with the same elements as the current sequence in a random order.
-
shuffle
Seq<T> shuffle(java.util.Random random)
Randomize the order of the elements in the current sequence using the given source of randomness.- Parameters:
random
- A random number generator- Returns:
- a sequence with the same elements as the current sequence in a random order.
-
slice
Seq<T> slice(int beginIndex, int endIndex)
Returns a Seq that is a slice of this. The slice begins with the element at the specifiedbeginIndex
and extends to the element at indexendIndex - 1
.Examples:
List.of(1, 2, 3, 4).slice(1, 3); // = (2, 3) List.of(1, 2, 3, 4).slice(0, 4); // = (1, 2, 3, 4) List.of(1, 2, 3, 4).slice(2, 2); // = () List.of(1, 2).slice(1, 0); // = () List.of(1, 2).slice(-10, 10); // = (1, 2)
subSequence(int, int)
which throws in some cases instead of returning a sequence.- Parameters:
beginIndex
- the beginning index, inclusiveendIndex
- the end index, exclusive- Returns:
- the specified slice
-
sorted
Seq<T> sorted()
Sorts this elements according to their natural order. If this elements are notComparable
, ajava.lang.ClassCastException
may be thrown.- Returns:
- A sorted version of this
- Throws:
java.lang.ClassCastException
- if this elements are notComparable
-
sorted
Seq<T> sorted(java.util.Comparator<? super T> comparator)
Sorts this elements according to the providedComparator
. If this elements are notComparable
, ajava.lang.ClassCastException
may be thrown.- Parameters:
comparator
- A comparator- Returns:
- a sorted version of this
-
sortBy
<U extends java.lang.Comparable<? super U>> Seq<T> sortBy(java.util.function.Function<? super T,? extends U> mapper)
Sorts this elements by comparing the elements in a different domain, using the givenmapper
.- Type Parameters:
U
- The domain where elements are compared- Parameters:
mapper
- A mapper- Returns:
- a sorted version of this
- Throws:
java.lang.NullPointerException
- ifmapper
is null
-
sortBy
<U> Seq<T> sortBy(java.util.Comparator<? super U> comparator, java.util.function.Function<? super T,? extends U> mapper)
Sorts this elements by comparing the elements in a different domain, using the givenmapper
.- Type Parameters:
U
- The domain where elements are compared- Parameters:
comparator
- A comparatormapper
- A mapper- Returns:
- a sorted version of this
- Throws:
java.lang.NullPointerException
- ifcomparator
ormapper
is null
-
splitAt
Tuple2<? extends Seq<T>,? extends Seq<T>> splitAt(int n)
Splits a Seq at the specified index. The result ofsplitAt(n)
is equivalent toTuple.of(take(n), drop(n))
.- Parameters:
n
- An index.- Returns:
- A
Tuple
containing the first n and the remaining elements.
-
splitAt
Tuple2<? extends Seq<T>,? extends Seq<T>> splitAt(java.util.function.Predicate<? super T> predicate)
Splits a sequence at the first element which satisfies thePredicate
, e.g. Tuple(init, element+tail).- Parameters:
predicate
- An predicate- Returns:
- A
Tuple
containing divided sequences
-
splitAtInclusive
Tuple2<? extends Seq<T>,? extends Seq<T>> splitAtInclusive(java.util.function.Predicate<? super T> predicate)
Splits a sequence at the first element which satisfies thePredicate
, e.g. Tuple(init+element, tail).- Parameters:
predicate
- An predicate- Returns:
- A
Tuple
containing divided sequences
-
startsWith
default boolean startsWith(java.lang.Iterable<? extends T> that)
Tests whether this list starts with the given sequence.- Parameters:
that
- the sequence to test- Returns:
- true if that is empty or that is prefix of this collection, false otherwise.
-
startsWith
default boolean startsWith(java.lang.Iterable<? extends T> that, int offset)
Tests whether this list contains the given sequence at a given index.Note: If the both the receiver object this and the argument that are infinite sequences this method may not terminate.
- Parameters:
that
- the sequence to testoffset
- the index where the sequence is searched.- Returns:
- true if that is empty or that is prefix of this collection starting from the given offset, false otherwise.
-
subSequence
Seq<T> subSequence(int beginIndex)
Returns a Seq that is a subsequence of this. The subsequence begins with the element at the specifiedbeginIndex
and extends to the end of this Seq.Examples:
List.of(1, 2).subSequence(0); // = (1, 2) List.of(1, 2).subSequence(1); // = (2) List.of(1, 2).subSequence(2); // = () List.of(1, 2).subSequence(10); // throws IndexOutOfBoundsException List.of(1, 2).subSequence(-10); // throws IndexOutOfBoundsException
drop(int)
which is similar but does not throw.- Parameters:
beginIndex
- the beginning index, inclusive- Returns:
- the specified subsequence
- Throws:
java.lang.IndexOutOfBoundsException
- ifbeginIndex
is negative or larger than the length of thisString
object.
-
subSequence
Seq<T> subSequence(int beginIndex, int endIndex)
Returns a Seq that is a subsequence of this. The subsequence begins with the element at the specifiedbeginIndex
and extends to the element at indexendIndex - 1
.Examples:
List.of(1, 2, 3, 4).subSequence(1, 3); // = (2, 3) List.of(1, 2, 3, 4).subSequence(0, 4); // = (1, 2, 3, 4) List.of(1, 2, 3, 4).subSequence(2, 2); // = () List.of(1, 2).subSequence(1, 0); // throws IndexOutOfBoundsException List.of(1, 2).subSequence(-10, 1); // throws IndexOutOfBoundsException List.of(1, 2).subSequence(0, 10); // throws IndexOutOfBoundsException
slice(int, int)
which returns an empty sequence instead of throwing.- Parameters:
beginIndex
- the beginning index, inclusiveendIndex
- the end index, exclusive- Returns:
- the specified subsequence
- Throws:
java.lang.IndexOutOfBoundsException
- ifbeginIndex
orendIndex
is negative or ifendIndex
is greater thanlength()
java.lang.IllegalArgumentException
- ifbeginIndex
is greater thanendIndex
-
update
Seq<T> update(int index, T element)
Updates the given element at the specified index.- Parameters:
index
- an indexelement
- an element- Returns:
- a new Seq consisting of all previous elements, with a single one (at the given index), changed to the new value.
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
-
update
Seq<T> update(int index, java.util.function.Function<? super T,? extends T> updater)
Updates the given element at the specified index using the specified function.- Parameters:
index
- an indexupdater
- a function transforming the previous value- Returns:
- a new Seq consisting of all previous elements, with a single one (at the given index), changed to the new value.
- Throws:
java.lang.IndexOutOfBoundsException
- if this is empty, index < 0 or index >= length()
-
search
int search(T element)
Searches this sequence for a specific element. The sequence must already be sorted into ascending natural order. If it is not sorted, the results are undefined.If this sequence is an `IndexedSeq`, a binary search is used. Otherwise, a linear search is used.
- Parameters:
element
- the element to find- Returns:
- the index of the search element, if it is contained in the sequence;
otherwise,
(-(insertion point) - 1)
. The insertion point is defined as the point at which the element would be inserted into the sequence. Note that this guarantees that the return value will be >= 0 if and only if the element is found. - Throws:
java.lang.ClassCastException
- if T cannot be cast toComparable<? super T>
-
search
int search(T element, java.util.Comparator<? super T> comparator)
Searches this sequence for a specific element. The sequence must already be sorted into ascending order according to the specified comparator. If it is not sorted, the results are undefined.If this sequence is an `IndexedSeq`, a binary search is used. Otherwise, a linear search is used.
- Parameters:
element
- the element to findcomparator
- the comparator by which this sequence is ordered- Returns:
- the index of the search element, if it is contained in the sequence;
otherwise,
(-(insertion point) - 1)
. The insertion point is defined as the point at which the element would be inserted into the sequence. Note that this guarantees that the return value will be >= 0 if and only if the element is found.
-
distinct
Seq<T> distinct()
Description copied from interface:Traversable
Returns a new version of this which contains no duplicates. Elements are compared usingequals
.- Specified by:
distinct
in interfaceTraversable<T>
- Returns:
- a new
Traversable
containing this elements without duplicates
-
distinctBy
Seq<T> distinctBy(java.util.Comparator<? super T> comparator)
Description copied from interface:Traversable
Returns a new version of this which contains no duplicates. Elements are compared using the givencomparator
.- Specified by:
distinctBy
in interfaceTraversable<T>
- Parameters:
comparator
- A comparator- Returns:
- a new
Traversable
containing this elements without duplicates
-
distinctBy
<U> Seq<T> distinctBy(java.util.function.Function<? super T,? extends U> keyExtractor)
Description copied from interface:Traversable
Returns a new version of this which contains no duplicates. Elements mapped to keys which are compared usingequals
.The elements of the result are determined in the order of their occurrence - first match wins.
- Specified by:
distinctBy
in interfaceTraversable<T>
- Type Parameters:
U
- key type- Parameters:
keyExtractor
- A key extractor- Returns:
- a new
Traversable
containing this elements without duplicates
-
drop
Seq<T> drop(int n)
Description copied from interface:Traversable
Drops the first n elements of this or all elements, if this length < n.- Specified by:
drop
in interfaceTraversable<T>
- Parameters:
n
- The number of elements to drop.- Returns:
- a new instance consisting of all elements of this except the first n ones, or else the empty instance, if this has less than n elements.
-
dropUntil
Seq<T> dropUntil(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Drops elements until the predicate holds for the current element.- Specified by:
dropUntil
in interfaceTraversable<T>
- Parameters:
predicate
- A condition tested subsequently for this elements.- Returns:
- a new instance consisting of all elements starting from the first one which does satisfy the given predicate.
-
dropWhile
Seq<T> dropWhile(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Drops elements while the predicate holds for the current element.Note: This is essentially the same as
dropUntil(predicate.negate())
. It is intended to be used with method references, which cannot be negated directly.- Specified by:
dropWhile
in interfaceTraversable<T>
- Parameters:
predicate
- A condition tested subsequently for this elements.- Returns:
- a new instance consisting of all elements starting from the first one which does not satisfy the given predicate.
-
dropRight
Seq<T> dropRight(int n)
Description copied from interface:Traversable
Drops the last n elements of this or all elements, if this length < n.- Specified by:
dropRight
in interfaceTraversable<T>
- Parameters:
n
- The number of elements to drop.- Returns:
- a new instance consisting of all elements of this except the last n ones, or else the empty instance, if this has less than n elements.
-
dropRightUntil
Seq<T> dropRightUntil(java.util.function.Predicate<? super T> predicate)
Drops elements until the predicate holds for the current element, starting from the end.- Parameters:
predicate
- A condition tested subsequently for this elements, starting from the end.- Returns:
- a new instance consisting of all elements until and including the last one which does satisfy the given predicate.
- Throws:
java.lang.NullPointerException
- ifpredicate
is null
-
dropRightWhile
Seq<T> dropRightWhile(java.util.function.Predicate<? super T> predicate)
Drops elements while the predicate holds for the current element, starting from the end.Note: This is essentially the same as
dropRightUntil(predicate.negate())
. It is intended to be used with method references, which cannot be negated directly.- Parameters:
predicate
- A condition tested subsequently for this elements, starting from the end.- Returns:
- a new instance consisting of all elements until and including the last one which does not satisfy the given predicate.
- Throws:
java.lang.NullPointerException
- ifpredicate
is null
-
filter
Seq<T> filter(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Returns a new traversable consisting of all elements which satisfy the given predicate.- Specified by:
filter
in interfaceTraversable<T>
- Parameters:
predicate
- A predicate- Returns:
- a new traversable
-
filterNot
Seq<T> filterNot(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Returns a new traversable consisting of all elements which do not satisfy the given predicate.The default implementation is equivalent to
filter(predicate.negate()
- Specified by:
filterNot
in interfaceTraversable<T>
- Parameters:
predicate
- A predicate- Returns:
- a new traversable
-
reject
@Deprecated Seq<T> reject(java.util.function.Predicate<? super T> predicate)
Deprecated.Description copied from interface:Traversable
Returns a new traversable consisting of all elements which do not satisfy the given predicate.The default implementation is equivalent to
filter(predicate.negate()
- Specified by:
reject
in interfaceTraversable<T>
- Parameters:
predicate
- A predicate- Returns:
- a new traversable
-
flatMap
<U> Seq<U> flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends U>> mapper)
Description copied from interface:Traversable
FlatMaps this Traversable.- Specified by:
flatMap
in interfaceTraversable<T>
- Type Parameters:
U
- The resulting component type.- Parameters:
mapper
- A mapper- Returns:
- A new Traversable instance.
-
foldRight
default <U> U foldRight(U zero, java.util.function.BiFunction<? super T,? super U,? extends U> f)
Description copied from interface:Traversable
Folds this elements from the right, starting withzero
and successively callingcombine
.Example:
// = "!cba" List("a", "b", "c").foldRight("!", (x, xs) -> xs + x)
-
groupBy
<C> Map<C,? extends Seq<T>> groupBy(java.util.function.Function<? super T,? extends C> classifier)
Description copied from interface:Traversable
Groups this elements by classifying the elements.- Specified by:
groupBy
in interfaceTraversable<T>
- Type Parameters:
C
- classified class type- Parameters:
classifier
- A function which classifies elements into classes- Returns:
- A Map containing the grouped elements
- See Also:
Traversable.arrangeBy(Function)
-
grouped
Iterator<? extends Seq<T>> grouped(int size)
Description copied from interface:Traversable
Groups thisTraversable
into fixed size blocks.Let length be the length of this Iterable. Then grouped is defined as follows:
- If
this.isEmpty()
, the resultingIterator
is empty. - If
size <= length
, the resultingIterator
will containlength / size
blocks of sizesize
and maybe a non-empty block of sizelength % size
, if there are remaining elements. - If
size > length
, the resultingIterator
will contain one block of sizelength
.
[].grouped(1) = [] [].grouped(0) throws [].grouped(-1) throws [1,2,3,4].grouped(2) = [[1,2],[3,4]] [1,2,3,4,5].grouped(2) = [[1,2],[3,4],[5]] [1,2,3,4].grouped(5) = [[1,2,3,4]]
grouped(int)
is a special case of Traversable.sliding(int, int), i.e.grouped(size)
is the same assliding(size, size)
.- Specified by:
grouped
in interfaceTraversable<T>
- Parameters:
size
- a positive block size- Returns:
- A new Iterator of grouped blocks of the given size
- If
-
init
Seq<T> init()
Description copied from interface:Traversable
Dual of Traversable.tail(), returning all elements except the last.- Specified by:
init
in interfaceTraversable<T>
- Returns:
- a new instance containing all elements except the last.
-
initOption
Option<? extends Seq<T>> initOption()
Description copied from interface:Traversable
Dual of Traversable.tailOption(), returning all elements except the last asOption
.- Specified by:
initOption
in interfaceTraversable<T>
- Returns:
Some(traversable)
orNone
if this is empty.
-
map
<U> Seq<U> map(java.util.function.Function<? super T,? extends U> mapper)
Description copied from interface:Traversable
Maps the elements of thisTraversable
to elements of a new type preserving their order, if any.
-
orElse
Seq<T> orElse(java.lang.Iterable<? extends T> other)
Description copied from interface:Traversable
Returns thisTraversable
if it is nonempty, otherwise return the alternative.- Specified by:
orElse
in interfaceTraversable<T>
- Parameters:
other
- An alternativeTraversable
- Returns:
- this
Traversable
if it is nonempty, otherwise return the alternative.
-
orElse
Seq<T> orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
Description copied from interface:Traversable
Returns thisTraversable
if it is nonempty, otherwise return the result of evaluating supplier.- Specified by:
orElse
in interfaceTraversable<T>
- Parameters:
supplier
- An alternativeTraversable
supplier- Returns:
- this
Traversable
if it is nonempty, otherwise return the result of evaluating supplier.
-
partition
Tuple2<? extends Seq<T>,? extends Seq<T>> partition(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Creates a partition of thisTraversable
by splitting this elements in two in distinct traversables according to a predicate.- Specified by:
partition
in interfaceTraversable<T>
- Parameters:
predicate
- A predicate which classifies an element if it is in the first or the second traversable.- Returns:
- A disjoint union of two traversables. The first
Traversable
contains all elements that satisfy the givenpredicate
, the secondTraversable
contains all elements that don't. The original order of elements is preserved.
-
peek
Seq<T> peek(java.util.function.Consumer<? super T> action)
Description copied from interface:Value
Performs the givenaction
on the first element if this is an eager implementation. Performs the givenaction
on all elements (the first immediately, successive deferred), if this is a lazy implementation.
-
replace
Seq<T> replace(T currentElement, T newElement)
Description copied from interface:Traversable
Replaces the first occurrence (if exists) of the given currentElement with newElement.- Specified by:
replace
in interfaceTraversable<T>
- Parameters:
currentElement
- An element to be substituted.newElement
- A replacement for currentElement.- Returns:
- a Traversable containing all elements of this where the first occurrence of currentElement is replaced with newElement.
-
replaceAll
Seq<T> replaceAll(T currentElement, T newElement)
Description copied from interface:Traversable
Replaces all occurrences of the given currentElement with newElement.- Specified by:
replaceAll
in interfaceTraversable<T>
- Parameters:
currentElement
- An element to be substituted.newElement
- A replacement for currentElement.- Returns:
- a Traversable containing all elements of this where all occurrences of currentElement are replaced with newElement.
-
retainAll
Seq<T> retainAll(java.lang.Iterable<? extends T> elements)
Description copied from interface:Traversable
Keeps all occurrences of the given elements from this.- Specified by:
retainAll
in interfaceTraversable<T>
- Parameters:
elements
- Elements to be kept.- Returns:
- a Traversable containing all occurrences of the given elements.
-
scan
Seq<T> scan(T zero, java.util.function.BiFunction<? super T,? super T,? extends T> operation)
Description copied from interface:Traversable
Computes a prefix scan of the elements of the collection. Note: The neutral element z may be applied more than once.- Specified by:
scan
in interfaceTraversable<T>
- Parameters:
zero
- neutral element for the operator opoperation
- the associative operator for the scan- Returns:
- a new traversable collection containing the prefix scan of the elements in this traversable collection
-
scanLeft
<U> Seq<U> scanLeft(U zero, java.util.function.BiFunction<? super U,? super T,? extends U> operation)
Description copied from interface:Traversable
Produces a collection containing cumulative results of applying the operator going left to right. Note: will not terminate for infinite-sized collections. Note: might return different results for different runs, unless the underlying collection type is ordered.- Specified by:
scanLeft
in interfaceTraversable<T>
- Type Parameters:
U
- the type of the elements in the resulting collection- Parameters:
zero
- the initial valueoperation
- the binary operator applied to the intermediate result and the element- Returns:
- collection with intermediate results
-
scanRight
<U> Seq<U> scanRight(U zero, java.util.function.BiFunction<? super T,? super U,? extends U> operation)
Description copied from interface:Traversable
Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result. Note: will not terminate for infinite-sized collections. Note: might return different results for different runs, unless the underlying collection type is ordered.- Specified by:
scanRight
in interfaceTraversable<T>
- Type Parameters:
U
- the type of the elements in the resulting collection- Parameters:
zero
- the initial valueoperation
- the binary operator applied to the intermediate result and the element- Returns:
- collection with intermediate results
-
slideBy
Iterator<? extends Seq<T>> slideBy(java.util.function.Function<? super T,?> classifier)
Description copied from interface:Traversable
Slides a non-overlapping window of a variable size over thisTraversable
.Each window contains elements with the same class, as determined by
classifier
. Two consecutive values in thisTraversable
will be in the same window only ifclassifier
returns equal values for them. Otherwise, the values will constitute the last element of the previous window and the first element of the next window.Examples:
[].slideBy(Function.identity()) = [] [1,2,3,4,4,5].slideBy(Function.identity()) = [[1],[2],[3],[4,4],[5]] [1,2,3,10,12,5,7,20,29].slideBy(x -> x/10) = [[1,2,3],[10,12],[5,7],[20,29]]
- Specified by:
slideBy
in interfaceTraversable<T>
- Parameters:
classifier
- A function which classifies elements into classes- Returns:
- A new Iterator of windows of the grouped elements
-
sliding
Iterator<? extends Seq<T>> sliding(int size)
Description copied from interface:Traversable
Slides a window of a specificsize
and step size 1 over thisTraversable
by callingTraversable.sliding(int, int)
.- Specified by:
sliding
in interfaceTraversable<T>
- Parameters:
size
- a positive window size- Returns:
- a new Iterator of windows of a specific size using step size 1
-
sliding
Iterator<? extends Seq<T>> sliding(int size, int step)
Description copied from interface:Traversable
Slides a window of a specificsize
andstep
size over thisTraversable
.Examples:
[].sliding(1,1) = [] [1,2,3,4,5].sliding(2,3) = [[1,2],[4,5]] [1,2,3,4,5].sliding(2,4) = [[1,2],[5]] [1,2,3,4,5].sliding(2,5) = [[1,2]] [1,2,3,4].sliding(5,3) = [[1,2,3,4],[4]]
- Specified by:
sliding
in interfaceTraversable<T>
- Parameters:
size
- a positive window sizestep
- a positive step size- Returns:
- a new Iterator of windows of a specific size using a specific step size
-
span
Tuple2<? extends Seq<T>,? extends Seq<T>> span(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Returns a tuple where the first element is the longest prefix of elements that satisfy the givenpredicate
and the second element is the remainder.- Specified by:
span
in interfaceTraversable<T>
- Parameters:
predicate
- A predicate.- Returns:
- a
Tuple
containing the longest prefix of elements that satisfy p and the remainder.
-
tail
Seq<T> tail()
Description copied from interface:Traversable
Drops the first element of a non-empty Traversable.- Specified by:
tail
in interfaceTraversable<T>
- Returns:
- A new instance of Traversable containing all elements except the first.
-
tailOption
Option<? extends Seq<T>> tailOption()
Description copied from interface:Traversable
Drops the first element of a non-empty Traversable and returns anOption
.- Specified by:
tailOption
in interfaceTraversable<T>
- Returns:
Some(traversable)
orNone
if this is empty.
-
take
Seq<T> take(int n)
Description copied from interface:Traversable
Takes the first n elements of this or all elements, if this length < n.The result is equivalent to
sublist(0, max(0, min(length(), n)))
but does not throw ifn < 0
orn > length()
.In the case of
n < 0
the empty instance is returned, in the case ofn > length()
this is returned.- Specified by:
take
in interfaceTraversable<T>
- Parameters:
n
- The number of elements to take.- Returns:
- A new instance consisting of the first n elements of this or all elements, if this has less than n elements.
-
takeUntil
Seq<T> takeUntil(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Takes elements until the predicate holds for the current element.Note: This is essentially the same as
takeWhile(predicate.negate())
. It is intended to be used with method references, which cannot be negated directly.- Specified by:
takeUntil
in interfaceTraversable<T>
- Parameters:
predicate
- A condition tested subsequently for this elements.- Returns:
- a new instance consisting of all elements before the first one which does satisfy the given predicate.
-
takeWhile
Seq<T> takeWhile(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Takes elements while the predicate holds for the current element.- Specified by:
takeWhile
in interfaceTraversable<T>
- Parameters:
predicate
- A condition tested subsequently for the contained elements.- Returns:
- a new instance consisting of all elements before the first one which does not satisfy the given predicate.
-
takeRight
Seq<T> takeRight(int n)
Description copied from interface:Traversable
Takes the last n elements of this or all elements, if this length < n.The result is equivalent to
sublist(max(0, min(length(), length() - n)), n)
, i.e. takeRight will not throw ifn < 0
orn > length()
.In the case of
n < 0
the empty instance is returned, in the case ofn > length()
this is returned.- Specified by:
takeRight
in interfaceTraversable<T>
- Parameters:
n
- The number of elements to take.- Returns:
- A new instance consisting of the last n elements of this or all elements, if this has less than n elements.
-
takeRightUntil
Seq<T> takeRightUntil(java.util.function.Predicate<? super T> predicate)
Takes elements until the predicate holds for the current element, starting from the end.- Parameters:
predicate
- A condition tested subsequently for this elements, starting from the end.- Returns:
- a new instance consisting of all elements after the last one which does satisfy the given predicate.
- Throws:
java.lang.NullPointerException
- ifpredicate
is null
-
takeRightWhile
Seq<T> takeRightWhile(java.util.function.Predicate<? super T> predicate)
Takes elements while the predicate holds for the current element, starting from the end.Note: This is essentially the same as
takeRightUntil(predicate.negate())
. It is intended to be used with method references, which cannot be negated directly.- Parameters:
predicate
- A condition tested subsequently for this elements, starting from the end.- Returns:
- a new instance consisting of all elements after the last one which does not satisfy the given predicate.
- Throws:
java.lang.NullPointerException
- ifpredicate
is null
-
unzip
<T1,T2> Tuple2<? extends Seq<T1>,? extends Seq<T2>> unzip(java.util.function.Function<? super T,Tuple2<? extends T1,? extends T2>> unzipper)
Description copied from interface:Traversable
Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.- Specified by:
unzip
in interfaceTraversable<T>
- Type Parameters:
T1
- 1st element type of a pair returned by unzipperT2
- 2nd element type of a pair returned by unzipper- Parameters:
unzipper
- a function which converts elements of this to pairs- Returns:
- A pair of set containing elements split by unzipper
-
unzip3
<T1,T2,T3> Tuple3<? extends Seq<T1>,? extends Seq<T2>,? extends Seq<T3>> unzip3(java.util.function.Function<? super T,Tuple3<? extends T1,? extends T2,? extends T3>> unzipper)
Description copied from interface:Traversable
Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.- Specified by:
unzip3
in interfaceTraversable<T>
- Type Parameters:
T1
- 1st element type of a triplet returned by unzipperT2
- 2nd element type of a triplet returned by unzipperT3
- 3rd element type of a triplet returned by unzipper- Parameters:
unzipper
- a function which converts elements of this to pairs- Returns:
- A triplet of set containing elements split by unzipper
-
zip
<U> Seq<Tuple2<T,U>> zip(java.lang.Iterable<? extends U> that)
Description copied from interface:Traversable
Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs. If one of the two iterables is longer than the other, its remaining elements are ignored.The length of the returned traversable is the minimum of the lengths of this traversable and
that
iterable.- Specified by:
zip
in interfaceTraversable<T>
- Type Parameters:
U
- The type of the second half of the returned pairs.- Parameters:
that
- The Iterable providing the second half of each result pair.- Returns:
- a new traversable containing pairs consisting of corresponding elements of this traversable and
that
iterable.
-
zipWith
<U,R> Seq<R> zipWith(java.lang.Iterable<? extends U> that, java.util.function.BiFunction<? super T,? super U,? extends R> mapper)
Description copied from interface:Traversable
Returns a traversable formed from this traversable and another Iterable collection by mapping elements. If one of the two iterables is longer than the other, its remaining elements are ignored.The length of the returned traversable is the minimum of the lengths of this traversable and
that
iterable.- Specified by:
zipWith
in interfaceTraversable<T>
- Type Parameters:
U
- The type of the second parameter of the mapper.R
- The type of the mapped elements.- Parameters:
that
- The Iterable providing the second parameter of the mapper.mapper
- a mapper.- Returns:
- a new traversable containing mapped elements of this traversable and
that
iterable.
-
zipAll
<U> Seq<Tuple2<T,U>> zipAll(java.lang.Iterable<? extends U> that, T thisElem, U thatElem)
Description copied from interface:Traversable
Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.The length of the returned traversable is the maximum of the lengths of this traversable and
that
iterable.Special case: if this traversable is shorter than that elements, and that elements contains duplicates, the resulting traversable may be shorter than the maximum of the lengths of this and that because a traversable contains an element at most once.
If this Traversable is shorter than that, thisElem values are used to fill the result. If that is shorter than this Traversable, thatElem values are used to fill the result.
- Specified by:
zipAll
in interfaceTraversable<T>
- Type Parameters:
U
- The type of the second half of the returned pairs.- Parameters:
that
- The Iterable providing the second half of each result pair.thisElem
- The element to be used to fill up the result if this traversable is shorter than that.thatElem
- The element to be used to fill up the result if that is shorter than this traversable.- Returns:
- A new traversable containing pairs consisting of corresponding elements of this traversable and that.
-
zipWithIndex
Seq<Tuple2<T,java.lang.Integer>> zipWithIndex()
Description copied from interface:Traversable
Zips this traversable with its indices.- Specified by:
zipWithIndex
in interfaceTraversable<T>
- Returns:
- A new traversable containing all elements of this traversable paired with their index, starting with 0.
-
zipWithIndex
<U> Seq<U> zipWithIndex(java.util.function.BiFunction<? super T,? super java.lang.Integer,? extends U> mapper)
Description copied from interface:Traversable
Returns a traversable formed from this traversable and another Iterable collection by mapping elements. If one of the two iterables is longer than the other, its remaining elements are ignored.The length of the returned traversable is the minimum of the lengths of this traversable and
that
iterable.- Specified by:
zipWithIndex
in interfaceTraversable<T>
- Type Parameters:
U
- The type of the mapped elements.- Parameters:
mapper
- a mapper.- Returns:
- a new traversable containing mapped elements of this traversable and
that
iterable.
-
withDefaultValue
@Deprecated default Function1<java.lang.Integer,T> withDefaultValue(T defaultValue)
Deprecated.Will be removedTurns this sequence from a partial function into a total function that returns defaultValue for all indexes that are out of bounds.- Parameters:
defaultValue
- default value to return for out of bound indexes- Returns:
- a total function from index to T
-
withDefault
@Deprecated default Function1<java.lang.Integer,T> withDefault(java.util.function.Function<? super java.lang.Integer,? extends T> defaultFunction)
Deprecated.Will be removedTurns this sequence from a partial function into a total function that returns a value computed by defaultFunction for all indexes that are out of bounds.- Parameters:
defaultFunction
- function to evaluate for all out of bounds indexes.- Returns:
- a total function from index to T
-
isSequential
default boolean isSequential()
Description copied from interface:Traversable
Checks if the elements of this Traversable appear in encounter order.- Specified by:
isSequential
in interfaceTraversable<T>
- Returns:
- true, if the insertion order of elements is preserved, false otherwise.
-
-