Tree (vavr 1.0.0-alpha-4 API)

java.lang.Object
- io.vavr.collection.Tree<T>

Type Parameters:

T - component type of this Tree

All Implemented Interfaces:

Foldable<T>, Traversable<T>, Value<T>, java.io.Serializable, java.lang.Iterable<T>

Direct Known Subclasses:

Tree.Empty, Tree.Node
```
public abstract class Tree<T>
extends java.lang.Object
implements Traversable<T>, java.io.Serializable
```
A general Tree interface.

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Tree.Empty<T>` Deprecated. will be removed from the public API
`static class`	`Tree.Node<T>` Deprecated. will be removed from the public API
`static class`	`Tree.Order` Tree traversal order.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`branchCount()` Counts the number of branches of this tree.
`static <T,ID> List<Tree.Node<T>>`	`build(java.lang.Iterable<? extends T> source, java.util.function.Function<? super T,? extends ID> idMapper, java.util.function.Function<? super T,? extends ID> parentMapper)` Build a `List` with roots of `Tree` from flat source.
`<R> Tree<R>`	`collect(PartialFunction<? super T,? extends R> partialFunction)` Collects all elements that are in the domain of the given `partialFunction` by mapping the elements to type `R`.
`static <T> java.util.stream.Collector<T,java.util.ArrayList<T>,Tree<T>>`	`collector()` Returns a `Collector` which may be used in conjunction with `Stream.collect(java.util.stream.Collector)` to obtain a `Tree`.
`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.
`abstract java.lang.String`	`draw()` Creates a neat 2-dimensional drawing of a tree.
`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>`	`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.
`static <T> Tree.Empty<T>`	`empty()` Returns the singleton empty tree.
`static <T> Tree<T>`	`fill(int n, java.util.function.Supplier<? extends T> s)` Returns a Tree containing `n` values supplied by a given Supplier `s`.
`static <T> Tree<T>`	`fill(int n, T element)` Returns a Tree containing `n` times the given `element`
`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> Tree<U>`	`flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends U>> mapper)` FlatMaps this Traversable.
`<U> U`	`foldRight(U zero, java.util.function.BiFunction<? super T,? super U,? extends U> f)` Folds this elements from the right, starting with `zero` and successively calling `combine`.
`abstract List<Tree.Node<T>>`	`getChildren()` Returns the children of this tree.
`abstract T`	`getValue()` Gets the value of this tree.
`<C> Map<C,Seq<T>>`	`groupBy(java.util.function.Function<? super T,? extends C> classifier)` Groups this elements by classifying the elements.
`Iterator<Seq<T>>`	`grouped(int size)` Groups this `Traversable` into fixed size blocks.
`boolean`	`hasDefiniteSize()` Checks if this Traversable is known to have a finite size.
`T`	`head()` Returns the first element of a non-empty Traversable.
`Seq<T>`	`init()` Dual of Traversable.tail(), returning all elements except the last.
`Option<Seq<T>>`	`initOption()` Dual of Traversable.tailOption(), returning all elements except the last as `Option`.
`boolean`	`isAsync()` A `Tree` is computed synchronously.
`boolean`	`isBranch()` Checks if this Tree is a branch.
`boolean`	`isDistinct()` Checks if this Traversable may consist of distinct elements only.
`boolean`	`isLazy()` A `Tree` is computed eagerly.
`abstract boolean`	`isLeaf()` Checks if this Tree is a leaf.
`boolean`	`isSequential()` Checks if the elements of this Traversable appear in encounter order.
`boolean`	`isTraversableAgain()` Checks if this Traversable can be repeatedly traversed.
`Iterator<T>`	`iterator()` An iterator by means of head() and tail().
`Iterator<T>`	`iterator(Tree.Order order)` Traverses this tree values in a specific `Tree.Order`.
`int`	`leafCount()` Counts the number of leaves of this tree.
`<U> Tree<U>`	`map(java.util.function.Function<? super T,? extends U> mapper)` Maps the elements of this `Traversable` to elements of a new type preserving their order, if any.
`static <T> Tree<T>`	`narrow(Tree<? extends T> tree)` Narrows a widened `Tree<? extends T>` to `Tree<T>` by performing a type-safe cast.
`int`	`nodeCount()` Counts the number of nodes (i.e.
`static <T> Tree<T>`	`of(T... values)` Creates a Tree of the given elements.
`static <T> Tree.Node<T>`	`of(T value)` Returns a new Node containing the given value and having no children.
`static <T> Tree.Node<T>`	`of(T value, java.lang.Iterable<Tree.Node<T>> children)` Returns a new Node containing the given value and having the given children.
`static <T> Tree.Node<T>`	`of(T value, Tree.Node<T>... children)` Returns a new Node containing the given value and having the given children.
`static <T> Tree<T>`	`ofAll(java.lang.Iterable<? extends T> iterable)` Creates a Tree of the given elements.
`static <T> Tree<T>`	`ofAll(java.util.stream.Stream<? extends T> javaStream)` Creates a Tree that contains the elements of the given `Stream`.
`Tree<T>`	`orElse(java.lang.Iterable<? extends T> other)` Returns this `Traversable` if it is nonempty, otherwise return the alternative.
`Tree<T>`	`orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)` Returns this `Traversable` if it is nonempty, otherwise return the result of evaluating supplier.
`Tuple2<Seq<T>,Seq<T>>`	`partition(java.util.function.Predicate<? super T> predicate)` Creates a partition of this `Traversable` by splitting this elements in two in distinct traversables according to a predicate.
`Tree<T>`	`peek(java.util.function.Consumer<? super T> action)` Performs the given `action` on the first element if this is an eager implementation.
`static <T> Tree.Node<T>`	`recurse(T seed, java.util.function.Function<? super T,? extends java.lang.Iterable<? extends T>> descend)` Recursively builds a non-empty `Tree`, starting with the given `seed` value and proceeding in depth-first order.
`Tree<T>`	`replace(T currentElement, T newElement)` Replaces the first occurrence (if exists) of the given currentElement with newElement.
`Tree<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>`	`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.
`Iterator<Seq<T>>`	`slideBy(java.util.function.Function<? super T,?> classifier)` Slides a non-overlapping window of a variable size over this `Traversable`.
`Iterator<Seq<T>>`	`sliding(int size)` Slides a window of a specific `size` and step size 1 over this `Traversable` by calling `Traversable.sliding(int, int)`.
`Iterator<Seq<T>>`	`sliding(int size, int step)` Slides a window of a specific `size` and `step` size over this `Traversable`.
`Tuple2<Seq<T>,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 given `predicate` and the second element is the remainder.
`java.lang.String`	`stringPrefix()` Returns the name of this Value type, which is used by toString().
`static <T> Tree<T>`	`tabulate(int n, java.util.function.Function<? super java.lang.Integer,? extends T> f)` Returns a Tree containing `n` values of a given Function `f` over a range of integer values from 0 to `n - 1`.
`Seq<T>`	`tail()` Drops the first element of a non-empty Traversable.
`Option<Seq<T>>`	`tailOption()` Drops the first element of a non-empty Traversable and returns an `Option`.
`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>`	`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.
`abstract java.lang.String`	`toLispString()` Creates a Lisp-like representation of this `Tree`.
`<U> U`	`transform(java.util.function.Function<? super Tree<T>,? extends U> f)` Transforms this `Tree`.
`Seq<Tree.Node<T>>`	`traverse()` Traverses this tree in `Tree.Order.PRE_ORDER`.
`Seq<Tree.Node<T>>`	`traverse(Tree.Order order)` Traverses this tree in a specific order.
`Seq<T>`	`values()` Traverses this tree values in `Tree.Order.PRE_ORDER`.
`Seq<T>`	`values(Tree.Order order)` Traverses this tree values in a specific order.
`<U> Tree<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> Tree<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> Tree<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.
`Tree<Tuple2<T,java.lang.Integer>>`	`zipWithIndex()` Zips this traversable with its indices.
`<U> Tree<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 class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.vavr.collection.Traversable
arrangeBy, average, containsAll, count, equals, existsUnique, find, findLast, fold, foldLeft, forEachWithIndex, get, hashCode, headOption, isEmpty, isOrdered, isSingleValued, last, lastOption, length, max, maxBy, maxBy, min, minBy, minBy, mkCharSeq, mkCharSeq, mkCharSeq, mkString, mkString, mkString, narrow, nonEmpty, product, reduce, reduceLeft, reduceLeftOption, reduceOption, reduceRight, reduceRightOption, single, singleOption, size, spliterator, sum, toLinkedMap, toMap, toSortedMap, toSortedMap, unzip, unzip3

Methods inherited from interface io.vavr.Value
collect, collect, contains, corresponds, eq, exists, forAll, forEach, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, getOrNull, narrow, out, out, stderr, stdout, 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

- Method Detail
 - collector
```
public static <T> java.util.stream.Collector<T,java.util.ArrayList<T>,Tree<T>> collector()
```
 Returns a Collector which may be used in conjunction with Stream.collect(java.util.stream.Collector) to obtain a Tree.
 
 Type Parameters:
 
 T - Component type of the Tree.
 
 Returns:
 
 A io.vavr.collection.Tree Collector.
 - empty
```
public static <T> Tree.Empty<T> empty()
```
 Returns the singleton empty tree.
 
 Type Parameters:
 
 T - Type of tree values.
 
 Returns:
 
 The empty tree.
 - narrow
```
public static <T> Tree<T> narrow(Tree<? extends T> tree)
```
 Narrows a widened Tree<? extends T> to Tree<T> by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.
 
 Type Parameters:
 
 T - Component type of the Tree.
 
 Parameters:
 
 tree - An Tree.
 
 Returns:
 
 the given tree instance as narrowed type Tree<T>.
 - of
```
public static <T> Tree.Node<T> of(T value)
```
 Returns a new Node containing the given value and having no children.
 
 Type Parameters:
 
 T - Value type
 
 Parameters:
 
 value - A value
 
 Returns:
 
 A new Node instance.
 - of
```
@SafeVarargs
public static <T> Tree.Node<T> of(T value,
 Tree.Node<T>... children)
```
 Returns a new Node containing the given value and having the given children.
 
 Type Parameters:
 
 T - Value type
 
 Parameters:
 
 value - A value
 
 children - The child nodes, possibly empty
 
 Returns:
 
 A new Node instance.
 - of
```
public static <T> Tree.Node<T> of(T value,
 java.lang.Iterable<Tree.Node<T>> children)
```
 Returns a new Node containing the given value and having the given children.
 
 Type Parameters:
 
 T - Value type
 
 Parameters:
 
 value - A value
 
 children - The child nodes, possibly empty
 
 Returns:
 
 A new Node instance.
 - of
```
@SafeVarargs
public static <T> Tree<T> of(T... values)
```
 Creates a Tree of the given elements.
 
 Type Parameters:
 
 T - Component type of the List.
 
 Parameters:
 
 values - Zero or more values.
 
 Returns:
 
 A Tree containing the given values.
 
 Throws:
 
 java.lang.NullPointerException - if values is null
 - ofAll
```
public static <T> Tree<T> ofAll(java.lang.Iterable<? extends T> iterable)
```
 Creates a Tree of the given elements.
 If the given iterable is a tree, it is returned as result. if the iteration order of the elements is stable.
 
 Type Parameters:
 
 T - Component type of the List.
 
 Parameters:
 
 iterable - An Iterable of elements.
 
 Returns:
 
 A list containing the given elements in the same order.
 
 Throws:
 
 java.lang.NullPointerException - if elements is null
 - ofAll
```
public static <T> Tree<T> ofAll(java.util.stream.Stream<? extends T> javaStream)
```
 Creates a Tree that contains the elements of the given Stream.
 
 Type Parameters:
 
 T - Component type of the Stream.
 
 Parameters:
 
 javaStream - A Stream
 
 Returns:
 
 A Tree containing the given elements in the same order.
 - tabulate
```
public static <T> Tree<T> tabulate(int n,
 java.util.function.Function<? super java.lang.Integer,? extends T> f)
```
 Returns a Tree containing n values of a given Function f over a range of integer values from 0 to n - 1.
 
 Type Parameters:
 
 T - Component type of the Tree
 
 Parameters:
 
 n - The number of elements in the Tree
 
 f - The Function computing element values
 
 Returns:
 
 A Tree consisting of elements f(0),f(1), ..., f(n - 1)
 
 Throws:
 
 java.lang.NullPointerException - if f is null
 - fill
```
public static <T> Tree<T> fill(int n,
 java.util.function.Supplier<? extends T> s)
```
 Returns a Tree containing n values supplied by a given Supplier s.
 
 Type Parameters:
 
 T - Component type of the Tree
 
 Parameters:
 
 n - The number of elements in the Tree
 
 s - The Supplier computing element values
 
 Returns:
 
 A Tree of size n, where each element contains the result supplied by s.
 
 Throws:
 
 java.lang.NullPointerException - if s is null
 - fill
```
public static <T> Tree<T> fill(int n,
 T element)
```
 Returns a Tree containing n times the given element
 
 Type Parameters:
 
 T - Component type of the Tree
 
 Parameters:
 
 n - The number of elements in the Tree
 
 element - The element
 
 Returns:
 
 A Tree of size n, where each element is the given element.
 - recurse
```
public static <T> Tree.Node<T> recurse(T seed,
 java.util.function.Function<? super T,? extends java.lang.Iterable<? extends T>> descend)
```
 Recursively builds a non-empty Tree, starting with the given seed value and proceeding in depth-first order.
 The children of a node are created by
 1. applying the descend function to the node value
 2. calling this method recursively by using each derived child value as new seed (in iteration order).
 Example:
```
 // = (1 (2 4 5) 3)
 Tree.recurse(1, i ->
 (i == 1) ? List.of(2, 3) :
 (i == 2) ? List.(4, 5) :
 List.empty()
 ).toLispString();
 
```
 Type Parameters:
 
 T - Value type
 
 Parameters:
 
 seed - The start value for the Tree
 
 descend - A function to calculate the child values
 
 Returns:
 
 a new, non-empty Tree instance
 
 Throws:
 
 java.lang.NullPointerException - if descend is null
 - build
```
public static <T,ID> List<Tree.Node<T>> build(java.lang.Iterable<? extends T> source,
 java.util.function.Function<? super T,? extends ID> idMapper,
 java.util.function.Function<? super T,? extends ID> parentMapper)
```
 Build a List with roots of Tree from flat source.
 parentMapper must return null for root element.
```
 // = [(1, null, "I"), (2, 1, "II"), (3, 1, "III"), (4, 2, "IV"), (5, 2, "V")]
 List<MenuItem> items = ...; // MenuItem(id, parentId, label)

 // I
 // / \
 // II III
 // /\
 // IV V
 Tree<MenuItem> menu = Tree.build(items, MenuItem::getId, MenuItem::getParentId);
 
```
 Type Parameters:
 
 T - Value type
 
 ID - Id type
 
 Parameters:
 
 source - Flat source
 
 idMapper - A mapper from source item to unique identifier of that item
 
 parentMapper - A mapper from source item to unique identifier of parent item. Need return null for root items
 
 Returns:
 
 a new, maybe empty List instance with non-empty Tree instances
 
 Throws:
 
 java.lang.NullPointerException - if source, idMapper or parentMapper is null
 - collect
```
public final <R> Tree<R> collect(PartialFunction<? super T,? extends R> partialFunction)
```
 Description copied from interface: Traversable
 Collects all elements that are in the domain of the given partialFunction by mapping the elements to type R.
 More specifically, for each of this elements in iteration order first it is checked
```
 partialFunction.isDefinedAt(element)
 
```
 If the elements makes it through that filter, the mapped instance is added to the result collection
```
 R newElement = partialFunction.apply(element)
 
```
 Note:If this Traversable is ordered (i.e. extends Ordered, the caller of collect has to ensure that the elements are comparable (i.e. extend Comparable).
 Specified by:
 
 collect in interface Traversable<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 type R
 - getValue
```
public abstract T getValue()
```
 Gets the value of this tree.
 
 Returns:
 
 The value of this tree.
 
 Throws:
 
 java.lang.UnsupportedOperationException - if this tree is empty
 - getChildren
```
public abstract List<Tree.Node<T>> getChildren()
```
 Returns the children of this tree.
 
 Returns:
 
 the tree's children
 - isLeaf
```
public abstract boolean isLeaf()
```
 Checks if this Tree is a leaf. A tree is a leaf if it is a Node with no children. Because the empty tree is no Node, it is not a leaf by definition.
 
 Returns:
 
 true if this tree is a leaf, false otherwise.
 - isBranch
```
public final boolean isBranch()
```
 Checks if this Tree is a branch. A Tree is a branch if it is a Node which has children. Because the empty tree is not a Node, it is not a branch by definition.
 
 Returns:
 
 true if this tree is a branch, false otherwise.
 - isAsync
```
public final boolean isAsync()
```
 A Tree is computed synchronously.
 
 Specified by:
 
 isAsync in interface Value<T>
 
 Returns:
 
 false
 - isDistinct
```
public final boolean isDistinct()
```
 Description copied from interface: Traversable
 
 Checks if this Traversable may consist of distinct elements only.
 
 Specified by:
 
 isDistinct in interface Traversable<T>
 
 Returns:
 
 true if this Traversable may consist of distinct elements only, false otherwise.
 - isLazy
```
public final boolean isLazy()
```
 A Tree is computed eagerly.
 
 Specified by:
 
 isLazy in interface Value<T>
 
 Returns:
 
 false
 - isSequential
```
public final boolean isSequential()
```
 Description copied from interface: Traversable
 
 Checks if the elements of this Traversable appear in encounter order.
 
 Specified by:
 
 isSequential in interface Traversable<T>
 
 Returns:
 
 true, if the insertion order of elements is preserved, false otherwise.
 - iterator
```
public final Iterator<T> iterator(Tree.Order order)
```
 Traverses this tree values in a specific Tree.Order.
 
 Parameters:
 
 order - A traversal order
 
 Returns:
 
 A new Iterator
 - toLispString
```
public abstract java.lang.String toLispString()
```
 Creates a Lisp-like representation of this Tree.
 
 Returns:
 
 This Tree as Lisp-string, i.e. represented as list of lists.
 - transform
```
public final  U transform(java.util.function.Function<? super Tree<T>,? extends U> f)
```
 Transforms this Tree.
 
 Type Parameters:
 
 U - Type of transformation result
 
 Parameters:
 
 f - A transformation
 
 Returns:
 
 An instance of type U
 
 Throws:
 
 java.lang.NullPointerException - if f is null
 - traverse
```
public final Seq<Tree.Node<T>> traverse()
```
 Traverses this tree in Tree.Order.PRE_ORDER.
 
 Returns:
 
 A sequence of nodes.
 - traverse
```
public final Seq<Tree.Node<T>> traverse(Tree.Order order)
```
 Traverses this tree in a specific order.
 
 Parameters:
 
 order - the tree traversal order
 
 Returns:
 
 A sequence of nodes.
 
 Throws:
 
 java.lang.NullPointerException - if order is null
 - values
```
public final Seq<T> values()
```
 Traverses this tree values in Tree.Order.PRE_ORDER. Syntactic sugar for traverse().map(Node::getValue).
 
 Returns:
 
 A sequence of the tree values.
 - values
```
public final Seq<T> values(Tree.Order order)
```
 Traverses this tree values in a specific order. Syntactic sugar for traverse(order).map(Node::getValue).
 
 Parameters:
 
 order - the tree traversal order
 
 Returns:
 
 A sequence of the tree values.
 
 Throws:
 
 java.lang.NullPointerException - if order is null
 - branchCount
```
public final int branchCount()
```
 Counts the number of branches of this tree. The empty tree and a leaf have no branches.
 
 Returns:
 
 The number of branches of this tree.
 - leafCount
```
public final int leafCount()
```
 Counts the number of leaves of this tree. The empty tree has no leaves.
 
 Returns:
 
 The number of leaves of this tree.
 - nodeCount
```
public final int nodeCount()
```
 Counts the number of nodes (i.e. branches and leaves) of this tree. The empty tree has no nodes.
 
 Returns:
 
 The number of nodes of this tree.
 - distinct
```
public final Seq<T> distinct()
```
 Description copied from interface: Traversable
 
 Returns a new version of this which contains no duplicates. Elements are compared using equals.
 
 Specified by:
 
 distinct in interface Traversable<T>
 
 Returns:
 
 a new Traversable containing this elements without duplicates
 - distinctBy
```
public final 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 given comparator.
 
 Specified by:
 
 distinctBy in interface Traversable<T>
 
 Parameters:
 
 comparator - A comparator
 
 Returns:
 
 a new Traversable containing this elements without duplicates
 - distinctBy
```
public final  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 using equals.
 The elements of the result are determined in the order of their occurrence - first match wins.
 
 Specified by:
 
 distinctBy in interface Traversable<T>
 
 Type Parameters:
 
 U - key type
 
 Parameters:
 
 keyExtractor - A key extractor
 
 Returns:
 
 a new Traversable containing this elements without duplicates
 - drop
```
public final 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 interface Traversable<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.
 - dropRight
```
public final 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 interface Traversable<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.
 - dropUntil
```
public final 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 interface Traversable<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
```
public final 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 interface Traversable<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.
 - filter
```
public final 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 interface Traversable<T>
 
 Parameters:
 
 predicate - A predicate
 
 Returns:
 
 a new traversable
 - filterNot
```
public final 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 interface Traversable<T>
 
 Parameters:
 
 predicate - A predicate
 
 Returns:
 
 a new traversable
 - flatMap
```
public final  Tree 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 interface Traversable<T>
 
 Type Parameters:
 
 U - The resulting component type.
 
 Parameters:
 
 mapper - A mapper
 
 Returns:
 
 A new Traversable instance.
 - foldRight
```
public final  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 with zero and successively calling combine.
 Example:
```
 
 // = "!cba"
 List("a", "b", "c").foldRight("!", (x, xs) -> xs + x)
 
```
 Specified by:
 
 foldRight in interface Foldable<T>
 
 Specified by:
 
 foldRight in interface Traversable<T>
 
 Type Parameters:
 
 U - the type of the folded value
 
 Parameters:
 
 zero - A zero element to start with.
 
 f - A function which combines elements.
 
 Returns:
 
 a folded value
 - groupBy
```
public final <C> Map<C,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 interface Traversable<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
```
public final Iterator<Seq<T>> grouped(int size)
```
 Description copied from interface: Traversable
 Groups this Traversable into fixed size blocks.
 Let length be the length of this Iterable. Then grouped is defined as follows:
 - If this.isEmpty(), the resulting Iterator is empty.
 - If size <= length, the resulting Iterator will contain length / size blocks of size size and maybe a non-empty block of size length % size, if there are remaining elements.
 - If size > length, the resulting Iterator will contain one block of size length.
 Examples:
```
 
 [].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]]
 
 
```
 Please note that grouped(int) is a special case of Traversable.sliding(int, int), i.e. grouped(size) is the same as sliding(size, size).
 Specified by:
 
 grouped in interface Traversable<T>
 
 Parameters:
 
 size - a positive block size
 
 Returns:
 
 A new Iterator of grouped blocks of the given size
 - hasDefiniteSize
```
public final boolean hasDefiniteSize()
```
 Description copied from interface: Traversable
 
 Checks if this Traversable is known to have a finite size.
 This method should be implemented by classes only, i.e. not by interfaces.
 
 Specified by:
 
 hasDefiniteSize in interface Traversable<T>
 
 Returns:
 
 true, if this Traversable is known to have a finite size, false otherwise.
 - head
```
public final T head()
```
 Description copied from interface: Traversable
 
 Returns the first element of a non-empty Traversable.
 
 Specified by:
 
 head in interface Traversable<T>
 
 Returns:
 
 The first element of this Traversable.
 - init
```
public final Seq<T> init()
```
 Description copied from interface: Traversable
 
 Dual of Traversable.tail(), returning all elements except the last.
 
 Specified by:
 
 init in interface Traversable<T>
 
 Returns:
 
 a new instance containing all elements except the last.
 - initOption
```
public final Option<Seq<T>> initOption()
```
 Description copied from interface: Traversable
 
 Dual of Traversable.tailOption(), returning all elements except the last as Option.
 
 Specified by:
 
 initOption in interface Traversable<T>
 
 Returns:
 
 Some(traversable) or None if this is empty.
 - isTraversableAgain
```
public final boolean isTraversableAgain()
```
 Description copied from interface: Traversable
 
 Checks if this Traversable can be repeatedly traversed.
 This method should be implemented by classes only, i.e. not by interfaces.
 
 Specified by:
 
 isTraversableAgain in interface Traversable<T>
 
 Returns:
 
 true, if this Traversable is known to be traversable repeatedly, false otherwise.
 - iterator
```
public final Iterator<T> iterator()
```
 Description copied from interface: Traversable
 
 An iterator by means of head() and tail(). Subclasses may want to override this method.
 
 Specified by:
 
 iterator in interface Traversable<T>
 
 Specified by:
 
 iterator in interface Value<T>
 
 Specified by:
 
 iterator in interface java.lang.Iterable<T>
 
 Returns:
 
 A new Iterator of this Traversable elements.
 - map
```
public final  Tree map(java.util.function.Function<? super T,? extends U> mapper)
```
 Description copied from interface: Traversable
 
 Maps the elements of this Traversable to elements of a new type preserving their order, if any.
 
 Specified by:
 
 map in interface Traversable<T>
 
 Specified by:
 
 map in interface Value<T>
 
 Type Parameters:
 
 U - Component type of the target Traversable
 
 Parameters:
 
 mapper - A mapper.
 
 Returns:
 
 a mapped Traversable
 - orElse
```
public final Tree<T> orElse(java.lang.Iterable<? extends T> other)
```
 Description copied from interface: Traversable
 
 Returns this Traversable if it is nonempty, otherwise return the alternative.
 
 Specified by:
 
 orElse in interface Traversable<T>
 
 Parameters:
 
 other - An alternative Traversable
 
 Returns:
 
 this Traversable if it is nonempty, otherwise return the alternative.
 - orElse
```
public final Tree<T> orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
```
 Description copied from interface: Traversable
 
 Returns this Traversable if it is nonempty, otherwise return the result of evaluating supplier.
 
 Specified by:
 
 orElse in interface Traversable<T>
 
 Parameters:
 
 supplier - An alternative Traversable supplier
 
 Returns:
 
 this Traversable if it is nonempty, otherwise return the result of evaluating supplier.
 - partition
```
public final Tuple2<Seq<T>,Seq<T>> partition(java.util.function.Predicate<? super T> predicate)
```
 Description copied from interface: Traversable
 
 Creates a partition of this Traversable by splitting this elements in two in distinct traversables according to a predicate.
 
 Specified by:
 
 partition in interface Traversable<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 given predicate, the second Traversable contains all elements that don't. The original order of elements is preserved.
 - peek
```
public final Tree<T> peek(java.util.function.Consumer<? super T> action)
```
 Description copied from interface: Value
 
 Performs the given action on the first element if this is an eager implementation. Performs the given action on all elements (the first immediately, successive deferred), if this is a lazy implementation.
 
 Specified by:
 
 peek in interface Traversable<T>
 
 Specified by:
 
 peek in interface Value<T>
 
 Parameters:
 
 action - The action that will be performed on the element(s).
 
 Returns:
 
 this instance
 - replace
```
public final Tree<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 interface Traversable<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
```
public final Tree<T> replaceAll(T currentElement,
 T newElement)
```
 Description copied from interface: Traversable
 
 Replaces all occurrences of the given currentElement with newElement.
 
 Specified by:
 
 replaceAll in interface Traversable<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
```
public final 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 interface Traversable<T>
 
 Parameters:
 
 elements - Elements to be kept.
 
 Returns:
 
 a Traversable containing all occurrences of the given elements.
 - scan
```
public final 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 interface Traversable<T>
 
 Parameters:
 
 zero - neutral element for the operator op
 
 operation - the associative operator for the scan
 
 Returns:
 
 a new traversable collection containing the prefix scan of the elements in this traversable collection
 - scanLeft
```
public final  Seq 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 interface Traversable<T>
 
 Type Parameters:
 
 U - the type of the elements in the resulting collection
 
 Parameters:
 
 zero - the initial value
 
 operation - the binary operator applied to the intermediate result and the element
 
 Returns:
 
 collection with intermediate results
 - scanRight
```
public final  Seq 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 interface Traversable<T>
 
 Type Parameters:
 
 U - the type of the elements in the resulting collection
 
 Parameters:
 
 zero - the initial value
 
 operation - the binary operator applied to the intermediate result and the element
 
 Returns:
 
 collection with intermediate results
 - slideBy
```
public final Iterator<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 this Traversable.
 Each window contains elements with the same class, as determined by classifier. Two consecutive values in this Traversable will be in the same window only if classifier 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 interface Traversable<T>
 
 Parameters:
 
 classifier - A function which classifies elements into classes
 
 Returns:
 
 A new Iterator of windows of the grouped elements
 - sliding
```
public final Iterator<Seq<T>> sliding(int size)
```
 Description copied from interface: Traversable
 
 Slides a window of a specific size and step size 1 over this Traversable by calling Traversable.sliding(int, int).
 
 Specified by:
 
 sliding in interface Traversable<T>
 
 Parameters:
 
 size - a positive window size
 
 Returns:
 
 a new Iterator of windows of a specific size using step size 1
 - sliding
```
public final Iterator<Seq<T>> sliding(int size,
 int step)
```
 Description copied from interface: Traversable
 Slides a window of a specific size and step size over this Traversable.
 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]]
 
 
```
 Specified by:
 
 sliding in interface Traversable<T>
 
 Parameters:
 
 size - a positive window size
 
 step - a positive step size
 
 Returns:
 
 a new Iterator of windows of a specific size using a specific step size
 - span
```
public final Tuple2<Seq<T>,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 given predicate and the second element is the remainder.
 
 Specified by:
 
 span in interface Traversable<T>
 
 Parameters:
 
 predicate - A predicate.
 
 Returns:
 
 a Tuple containing the longest prefix of elements that satisfy p and the remainder.
 - stringPrefix
```
public final java.lang.String stringPrefix()
```
 Description copied from interface: Value
 
 Returns the name of this Value type, which is used by toString().
 
 Specified by:
 
 stringPrefix in interface Value<T>
 
 Returns:
 
 This type name.
 - tail
```
public final Seq<T> tail()
```
 Description copied from interface: Traversable
 
 Drops the first element of a non-empty Traversable.
 
 Specified by:
 
 tail in interface Traversable<T>
 
 Returns:
 
 A new instance of Traversable containing all elements except the first.
 - tailOption
```
public final Option<Seq<T>> tailOption()
```
 Description copied from interface: Traversable
 
 Drops the first element of a non-empty Traversable and returns an Option.
 
 Specified by:
 
 tailOption in interface Traversable<T>
 
 Returns:
 
 Some(traversable) or None if this is empty.
 - take
```
public final 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 if n < 0 or n > length().
 In the case of n < 0 the empty instance is returned, in the case of n > length() this is returned.
 
 Specified by:
 
 take in interface Traversable<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.
 - takeRight
```
public final 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 if n < 0 or n > length().
 In the case of n < 0 the empty instance is returned, in the case of n > length() this is returned.
 
 Specified by:
 
 takeRight in interface Traversable<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.
 - takeUntil
```
public final 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 interface Traversable<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
```
public final 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 interface Traversable<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.
 - zip
```
public final  Tree<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 interface Traversable<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
```
public final <U,R> Tree<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 interface Traversable<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
```
public final  Tree<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 interface Traversable<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
```
public final Tree<Tuple2<T,java.lang.Integer>> zipWithIndex()
```
 Description copied from interface: Traversable
 
 Zips this traversable with its indices.
 
 Specified by:
 
 zipWithIndex in interface Traversable<T>
 
 Returns:
 
 A new traversable containing all elements of this traversable paired with their index, starting with 0.
 - zipWithIndex
```
public final  Tree 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 interface Traversable<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.
 - draw
```
public abstract java.lang.String draw()
```
 Creates a neat 2-dimensional drawing of a tree. Unicode characters are used to draw node junctions.
 
 Returns:
 
 A nice string representation of the tree.

Class Tree<T>

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface io.vavr.collection.Traversable

Methods inherited from interface io.vavr.Value

Method Detail

collector

empty

narrow

of

of

of

of

ofAll

ofAll

tabulate

fill

fill

recurse

build

collect

getValue

getChildren

isLeaf

isBranch

isAsync

isDistinct

isLazy

isSequential

iterator

toLispString

transform

traverse

traverse

values

values

branchCount

leafCount

nodeCount

distinct

distinctBy

distinctBy

drop

dropRight

dropUntil

dropWhile

filter

filterNot

flatMap

foldRight

groupBy

grouped

hasDefiniteSize

head

init

initOption

isTraversableAgain

iterator

map

orElse

orElse

partition

peek

replace

replaceAll

retainAll

scan

scanLeft

scanRight

slideBy

sliding

sliding

span

stringPrefix

tail

tailOption

take

takeRight

takeUntil