Tree (Stanford JavaNLP API)

java.lang.Object
- java.util.AbstractCollection<Tree>
- - edu.stanford.nlp.trees.Tree

All Implemented Interfaces:

Label, Labeled, Scored, java.io.Serializable, java.lang.Iterable<Tree>, java.util.Collection<Tree>

Direct Known Subclasses:

LabeledScoredTreeNode, SimpleTree, TreeGraphNode
```
public abstract class Tree
extends java.util.AbstractCollection<Tree>
implements Label, Labeled, Scored, java.io.Serializable
```
The abstract class Tree is used to collect all of the tree types, and acts as a generic extensible type. This is the standard implementation of inheritance-based polymorphism. All Tree objects support accessors for their children (a Tree[]), their label (a Label), and their score (a double). However, different concrete implementations may or may not include the latter two, in which case a default value is returned. The class Tree defines no data fields. The two abstract methods that must be implemented are: children(), and treeFactory(). Notes that setChildren(Tree[]) is now an optional operation, whereas it was previously required to be implemented. There is now support for finding the parent of a tree. This may be done by search from a tree root, or via a directly stored parent. The Tree class now implements the Collection interface: in terms of this, each node of the tree is an element of the collection; hence one can explore the tree by using the methods of this interface. A Tree is regarded as a read-only Collection (even though the Tree class has various methods that modify trees). Moreover, the implementation is not thread-safe: no attempt is made to detect and report concurrent modifications.

Author:

Christopher Manning, Dan Klein, Sarah Spikes (sdspikes@cs.stanford.edu) - filled in types

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

static Tree[] EMPTY_TREE_ARRAY
A leaf node should have a zero-length array for its children.

Fields
Modifier and Type	Field and Description
`static Tree[]`	`EMPTY_TREE_ARRAY` A leaf node should have a zero-length array for its children.

Constructor Summary

Constructors
Constructor and Description

Tree()

Constructors
Constructor and Description
`Tree()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addChild(int i, Tree t)` Adds the tree t at the index position among the daughters.
`void`	`addChild(Tree t)` Adds the tree t at the last index position among the daughters.
`Tree`	`ancestor(int height, Tree root)` Return the ancestor tree node `height` nodes up from the current node.
`boolean`	`cCommands(Tree t1, Tree t2)` Given nodes `t1` and `t2` which are dominated by this node, returns `true` iff `t1` c-commands `t2`.
`abstract Tree[]`	`children()` Returns an array of children for the current node.
`java.util.Set<Constituent>`	`constituents()` Returns the Constituents generated by the parse tree.
`java.util.Set<Constituent>`	`constituents(ConstituentFactory cf)` Returns the Constituents generated by the parse tree.
`java.util.Set<Constituent>`	`constituents(ConstituentFactory cf, boolean charLevel)` Returns the Constituents generated by the parse tree.
`java.util.Set<Constituent>`	`constituents(ConstituentFactory cf, boolean charLevel, java.util.function.Predicate<Tree> filter)`
`java.util.Set<Constituent>`	`constituents(ConstituentFactory cf, int maxDepth)` Returns the Constituents generated by the parse tree.
`Tree`	`deepCopy()` Makes a deep copy of not only the Tree structure but of the labels as well.
`Tree`	`deepCopy(TreeFactory tf)` Makes a deep copy of not only the Tree structure but of the labels as well.
`Tree`	`deepCopy(TreeFactory tf, LabelFactory lf)` Makes a deep copy of not only the Tree structure but of the labels as well.
`java.util.Set<Dependency<Label,Label,java.lang.Object>>`	`dependencies()` Return a Set of TaggedWord-TaggedWord dependencies, represented as Dependency objects, for the Tree.
`java.util.Set<Dependency<Label,Label,java.lang.Object>>`	`dependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f)`
`java.util.Set<Dependency<Label,Label,java.lang.Object>>`	`dependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f, boolean isConcrete, boolean copyLabel, boolean copyPosTag)` Return a set of TaggedWord-TaggedWord dependencies, represented as Dependency objects, for the Tree.
`int`	`depth()` Finds the depth of the tree.
`int`	`depth(Tree node)` Finds the distance from this node to the specified node.
`boolean`	`dominates(Tree t)` Returns true if `this` dominates the Tree passed in as an argument.
`java.util.List<Tree>`	`dominationPath(Tree t)` Returns the path of nodes leading down to a dominated node, including `this` and the dominated node itself.
`boolean`	`equals(java.lang.Object o)` Implements equality for Tree's.
`Tree`	`firstChild()` Returns the first child of a tree, or `null` if none.
`Tree`	`flatten()` Return a flattened version of a tree.
`Tree`	`flatten(TreeFactory tf)` Return a flattened version of a tree.
`Tree`	`getChild(int i)` Return the child at some daughter index.
`java.util.List<Tree>`	`getChildrenAsList()` Returns a List of children for the current node.
`<T extends Tree> java.util.List<T>`	`getLeaves()` Gets the leaves of the tree.
`<T extends Tree> java.util.List<T>`	`getLeaves(java.util.List<T> list)` Gets the leaves of the tree.
`Tree`	`getNodeNumber(int i)` Fetches the `i`th node in the tree, with node numbers defined as in `nodeNumber(Tree)`.
`IntPair`	`getSpan()` Returns SpanAnnotation of this node, or null if annotation is not assigned.
`int`	`hashCode()` Implements a hashCode for Tree's.
`Tree`	`headPreTerminal(HeadFinder hf)` Returns the preterminal tree that is the head of the tree.
`Tree`	`headTerminal(HeadFinder hf)` Returns the tree leaf that is the head of the tree.
`Tree`	`headTerminal(HeadFinder hf, Tree parent)` Returns the tree leaf that is the head of the tree.
`void`	`indentedListPrint()` Indented list printing of a tree.
`void`	`indentedListPrint(java.io.PrintWriter pw, boolean printScores)` Indented list printing of a tree.
`void`	`indentedXMLPrint()` Indented xml printing of a tree.
`void`	`indentedXMLPrint(java.io.PrintWriter pw, boolean printScores)` Indented xml printing of a tree.
`void`	`indexLeaves()` Assign sequential integer indices to the leaves of the tree rooted at this `Tree`, starting with 1.
`void`	`indexLeaves(boolean overWrite)` Index the leaves, and optionally overwrite existing IndexAnnotations if they exist.
`int`	`indexLeaves(int startIndex, boolean overWrite)` Assign sequential integer indices to the leaves of the subtree rooted at this `Tree`, beginning with `startIndex`, and traversing the leaves from left to right.
`void`	`indexSpans()` Index all spans (constituents) in the tree.
`void`	`indexSpans(int startIndex)`
`Pair<java.lang.Integer,java.lang.Integer>`	`indexSpans(MutableInteger startIndex)` Assigns span indices (BeginIndexAnnotation and EndIndexAnnotation) to all nodes in a tree.
`void`	`insertDtr(Tree dtr, int position)` insert `dtr` after `position` existing daughters in `this`.
`boolean`	`isBinarized()` Returns whether this node is the root of a possibly binarized tree.
`boolean`	`isBinary()` Returns whether this node is the root of a possibly binary tree.
`boolean`	`isLeaf()` Says whether a node is a leaf.
`boolean`	`isPhrasal()` Return whether this node is a phrasal node or not.
`boolean`	`isPrePreTerminal()` Return whether all the children of this node are preterminals or not.
`boolean`	`isPreTerminal()` Return whether this node is a preterminal or not.
`boolean`	`isUnaryRewrite()` Says whether the current node has only one child.
`java.util.Iterator<Tree>`	`iterator()` Returns an iterator over all the nodes of the tree.
`Tree`	`joinNode(Tree t1, Tree t2)` Given nodes `t1` and `t2` which are dominated by this node, returns their "join node": the node `j` such that `j` dominates both `t1` and `t2`, and every other node which dominates both `t1` and `t2` dominates `j`.
`Label`	`label()` Returns the label associated with the current node, or null if there is no label.
`java.util.List<LabeledWord>`	`labeledYield()`
`java.util.List<LabeledWord>`	`labeledYield(java.util.List<LabeledWord> ty)`
`LabelFactory`	`labelFactory()` Returns a factory that makes labels of the same type as this one.
`java.util.Collection<Label>`	`labels()` Get the set of all node and leaf `Label`s, null or otherwise, contained in the tree.
`Tree`	`lastChild()` Returns the last child of a tree, or `null` if none.
`int`	`leftCharEdge(Tree node)` Returns the positional index of the left edge of node within the tree, as measured by characters.
`Tree`	`localTree()` Returns a new Tree that represents the local Tree at a certain node.
`java.util.Set<Tree>`	`localTrees()` Returns a set of one level `Tree`s that ares the local trees of the tree.
`java.util.Set<Dependency<Label,Label,java.lang.Object>>`	`mapDependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f, HeadFinder hf)` Return a set of Label-Label dependencies, represented as Dependency objects, for the Tree.
`java.util.Set<Dependency<Label,Label,java.lang.Object>>`	`mapDependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f, HeadFinder hf, java.lang.String rootName)` Return a set of Label-Label dependencies, represented as Dependency objects, for the Tree.
`int`	`nodeNumber(Tree root)` Calculates the node's number, defined as the number of nodes traversed in a left-to-right, depth-first search of the tree starting at `root` and ending at `this`.
`java.lang.String`	`nodeString()` Returns the value of the node's label as a String.
`int`	`numChildren()` Says how many children a tree node has in its local tree.
`int`	`objectIndexOf(Tree tree)` Returns the position of a Tree in the children list, if present, or -1 if it is not present.
`Tree`	`parent()` Return the parent of the tree node.
`Tree`	`parent(Tree root)` Return the parent of the tree node.
`java.util.List<Tree>`	`pathNodeToNode(Tree t1, Tree t2)` Given nodes `t1` and `t2` which are dominated by this node, returns a list of all the nodes on the path from t1 to t2, inclusive, or null if none found.
`void`	`pennPrint()` Print the tree as done in Penn Treebank merged files.
`void`	`pennPrint(java.io.PrintStream ps)` Print the tree as done in Penn Treebank merged files.
`void`	`pennPrint(java.io.PrintStream ps, java.util.function.Function<Label,java.lang.String> labelFormatter)`
`void`	`pennPrint(java.io.PrintWriter pw)` Print the tree as done in Penn Treebank merged files.
`void`	`pennPrint(java.io.PrintWriter pw, java.util.function.Function<Label,java.lang.String> labelFormatter)`
`java.lang.String`	`pennString()` Calls `pennPrint()` and saves output to a String
`void`	`percolateHeadAnnotations(HeadFinder hf)` Finds the head words of each tree and assigns HeadWordLabelAnnotation on each node pointing to the correct CoreLabel.
`void`	`percolateHeadIndices()` Percolates terminal indices through a dependency tree.
`void`	`percolateHeads(HeadFinder hf)` Finds the heads of the tree.
`java.util.List<Tree>`	`postOrderNodeList()`
`java.util.List<Tree>`	`preOrderNodeList()`
`java.util.List<Label>`	`preTerminalYield()` Gets the preterminal yield (i.e., tags) of the tree.
`java.util.List<Label>`	`preTerminalYield(java.util.List<Label> y)` Gets the preterminal yield (i.e., tags) of the tree.
`void`	`printLocalTree()`
`void`	`printLocalTree(java.io.PrintWriter pw)` Only prints the local tree structure, does not recurse
`Tree`	`prune(java.util.function.Predicate<Tree> filter)` Creates a deep copy of the tree, where all nodes that the filter does not accept and all children of such nodes are pruned.
`Tree`	`prune(java.util.function.Predicate<Tree> filter, TreeFactory tf)` Creates a deep copy of the tree, where all nodes that the filter does not accept and all children of such nodes are pruned.
`Tree`	`removeChild(int i)` Destructively removes the child at some daughter index and returns it.
`int`	`rightCharEdge(Tree node)` Returns the positional index of the right edge of node within the tree, as measured by characters.
`double`	`score()` Returns the score associated with the current node, or NaN if there is no score.
`Tree`	`setChild(int i, Tree t)` Replaces the `i`th child of `this` with the tree t.
`void`	`setChildren(java.util.List<? extends Tree> childTreesList)` Set the children of this tree node to the given list.
`void`	`setChildren(Tree[] children)` Set the children of this node to be the children given in the array.
`void`	`setFromString(java.lang.String labelStr)` Set the contents of this label to this `String` representing the complete contents of the label.
`void`	`setLabel(Label label)` Sets the label associated with the current node, if there is one.
`void`	`setLabels(java.util.Collection<Label> c)` Sets the labels associated with this object.
`void`	`setScore(double score)` Sets the score associated with the current node, if there is one.
`void`	`setSpans()` Assign a SpanAnnotation on each node of this tree.
`void`	`setValue(java.lang.String value)` Set the value for the label (if one is stored).
`java.util.List<Tree>`	`siblings(Tree root)` Returns the siblings of this Tree node.
`int`	`size()` Returns the number of nodes the tree contains.
`Tree`	`skipRoot()` Returns first child if this is unary and if the label at the current node is either "ROOT" or empty.
`java.lang.String`	`spanString()` Return String of leaves spanned by this tree assuming they are CoreLabel's Throws an IllegalArgumentException if the leaves are not CoreLabels that contain text info as in the typical use case of a Tree generated by a pipeline
`Tree`	`spliceOut(java.util.function.Predicate<Tree> nodeFilter)` Creates a (partial) deep copy of the tree, where all nodes that the filter does not accept are spliced out.
`Tree`	`spliceOut(java.util.function.Predicate<Tree> nodeFilter, TreeFactory tf)` Creates a (partial) deep copy of the tree, where all nodes that the filter does not accept are spliced out.
`java.util.List<Tree>`	`subTreeList()` Get the list of all subtrees inside the tree by returning a tree rooted at each node.
`java.util.Set<Tree>`	`subTrees()` Get the set of all subtrees inside the tree by returning a tree rooted at each node.
`<T extends java.util.Collection<Tree>> T`	`subTrees(T n)` Add the set of all subtrees inside a tree (including the tree itself) to the given `Collection`.
`java.util.List<CoreLabel>`	`taggedLabeledYield()` Returns a `List<CoreLabel>` from the tree.
`java.util.ArrayList<TaggedWord>`	`taggedYield()` Gets the tagged yield of the tree.
`<X extends java.util.List<TaggedWord>> X`	`taggedYield(X ty)` Gets the tagged yield of the tree -- that is, get the preterminals as well as the terminals.
`java.lang.String`	`toString()` Converts parse tree to string in Penn Treebank format.
`java.lang.StringBuilder`	`toStringBuilder(java.lang.StringBuilder sb)` Appends the printed form of a parse tree (as a bracketed String) to a `StringBuilder`.
`java.lang.StringBuilder`	`toStringBuilder(java.lang.StringBuilder sb, java.util.function.Function<Label,java.lang.String> labelFormatter)` Appends the printed form of a parse tree (as a bracketed String) to a `StringBuilder`.
`Tree`	`transform(TreeTransformer transformer)` Create a transformed Tree.
`Tree`	`transform(TreeTransformer transformer, TreeFactory tf)` Create a transformed Tree.
`abstract TreeFactory`	`treeFactory()` Return a `TreeFactory` that produces trees of the appropriate type.
`Tree`	`treeSkeletonConstituentCopy()` Returns a deep copy of everything but the leaf labels.
`Tree`	`treeSkeletonConstituentCopy(TreeFactory tf, LabelFactory lf)`
`Tree`	`treeSkeletonCopy()` Create a deep copy of the tree structure.
`Tree`	`treeSkeletonCopy(TreeFactory tf)` Create a deep copy of the tree structure.
`static java.lang.String`	`updateBrackets(java.lang.String text)`
`Tree`	`upperMostUnary(Tree root)` Return the highest node of the (perhaps trivial) unary chain that this node is part of.
`java.lang.String`	`value()` Return a String representation of just the "main" value of this label.
`static Tree`	`valueOf(java.lang.String str)` This gives you a tree from a String representation (as a bracketed Tree, of the kind produced by `toString()`, `pennPrint()`, or as in the Penn Treebank).
`static Tree`	`valueOf(java.lang.String str, TreeReaderFactory trf)` This gives you a tree from a String representation (as a bracketed Tree, of the kind produced by `toString()`, `pennPrint()`, or as in the Penn Treebank.
`java.util.ArrayList<Label>`	`yield()` Gets the yield of the tree.
`java.util.ArrayList<Label>`	`yield(java.util.ArrayList<Label> y)` Gets the yield of the tree.
`<T> java.util.List<T>`	`yield(java.util.List<T> y)` Gets the yield of the tree.
`<X extends HasWord> java.util.ArrayList<X>`	`yieldHasWord()`
`<X extends HasWord> java.util.ArrayList<X>`	`yieldHasWord(java.util.ArrayList<X> y)`
`java.util.ArrayList<Word>`	`yieldWords()`
`java.util.ArrayList<Word>`	`yieldWords(java.util.ArrayList<Word> y)`

Methods inherited from class java.util.AbstractCollection
add, addAll, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection
parallelStream, removeIf, spliterator, stream

Methods inherited from interface java.lang.Iterable
forEach

- Field Detail
  - EMPTY_TREE_ARRAY
```
public static final Tree[] EMPTY_TREE_ARRAY
```
    A leaf node should have a zero-length array for its children. For efficiency, classes can use this array as a return value for children() for leaf nodes if desired. This can also be used elsewhere when you want an empty Tree array.
- Constructor Detail
  - Tree
```
public Tree()
```
- Method Detail
  - isLeaf
```
public boolean isLeaf()
```
    Says whether a node is a leaf. Can be used on an arbitrary Tree. Being a leaf is defined as having no children. This must be implemented as returning a zero-length Tree[] array for children().
    
    Returns:
    
    true if this object is a leaf
  - numChildren
```
public int numChildren()
```
    Says how many children a tree node has in its local tree. Can be used on an arbitrary Tree. Being a leaf is defined as having no children.
    
    Returns:
    
    The number of direct children of the tree node
  - isUnaryRewrite
```
public boolean isUnaryRewrite()
```
    Says whether the current node has only one child. Can be used on an arbitrary Tree.
    
    Returns:
    
    Whether the node heads a unary rewrite
  - isPreTerminal
```
public boolean isPreTerminal()
```
    Return whether this node is a preterminal or not. A preterminal is defined to be a node with one child which is itself a leaf.
    
    Returns:
    
    true if the node is a preterminal; false otherwise
  - isPrePreTerminal
```
public boolean isPrePreTerminal()
```
    Return whether all the children of this node are preterminals or not. A preterminal is defined to be a node with one child which is itself a leaf. Considered false if the node has no children
    
    Returns:
    
    true if the node is a prepreterminal; false otherwise
  - isPhrasal
```
public boolean isPhrasal()
```
    Return whether this node is a phrasal node or not. A phrasal node is defined to be a node which is not a leaf or a preterminal. Worded positively, this means that it must have two or more children, or one child that is not a leaf.
    
    Returns:
    
    true if the node is phrasal; false otherwise
  - isBinary
```
public boolean isBinary()
```
    Returns whether this node is the root of a possibly binary tree. This happens if the tree and all of its descendants are either nodes with exactly two children, or are preterminals or leaves.
  - isBinarized
```
public boolean isBinarized()
```
    Returns whether this node is the root of a possibly binarized tree. This is slightly different from "binary" in that nodes with 1 or 2 children are allowed. The name is chosen because the TreeBinarizer produces trees which look like this.
  - equals
```
public boolean equals(java.lang.Object o)
```
    Implements equality for Tree's. Two Tree objects are equal if they have equal value()s, the same number of children, and their children are pairwise equal.
    
    Specified by:
    
    equals in interface java.util.Collection<Tree>
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    o - The object to compare with
    
    Returns:
    
    Whether two things are equal
  - hashCode
```
public int hashCode()
```
    Implements a hashCode for Tree's. Two trees should have the same hashcode if they are equal, so we hash on the label value and the children's label values.
    
    Specified by:
    
    hashCode in interface java.util.Collection<Tree>
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    The hash code
  - objectIndexOf
```
public int objectIndexOf(Tree tree)
```
    Returns the position of a Tree in the children list, if present, or -1 if it is not present. Trees are checked for presence with object equality, ==. Note that there are very few cases where an indexOf that used .equals() instead of == would be useful and correct. In most cases, you want to figure out which child of the parent a known tree is, so looking for object equality will be faster and will avoid cases where you happen to have two subtrees that are exactly the same.
    
    Parameters:
    
    tree - The tree to look for in children list
    
    Returns:
    
    Its index in the list or -1
  - children
```
public abstract Tree[] children()
```
    Returns an array of children for the current node. If there are no children (if the node is a leaf), this must return a Tree[] array of length 0. A null children() value for tree leaves was previously supported, but no longer is. A caller may assume that either isLeaf() returns true, or this node has a nonzero number of children.
    
    Returns:
    
    The children of the node
    
    See Also:
    
    getChildrenAsList()
  - getChildrenAsList
```
public java.util.List<Tree> getChildrenAsList()
```
    Returns a List of children for the current node. If there are no children, then a (non-null) List<Tree> of size 0 will be returned. The list has new list structure but pointers to, not copies of the children. That is, the returned list is mutable, and simply adding to or deleting items from it is safe, but beware changing the contents of the children.
    
    Returns:
    
    The children of the node
  - setChildren
```
public void setChildren(Tree[] children)
```
    Set the children of this node to be the children given in the array. This is an optional operation; by default it is unsupported. Note for subclasses that if there are no children, the children() method must return a Tree[] array of length 0. This class provides a EMPTY_TREE_ARRAY canonical zero-length Tree[] array to represent zero children, but it is not required that leaf nodes use this particular zero-length array to represent a leaf node.
    
    Parameters:
    
    children - The array of children, each a Tree
    
    See Also:
    
    setChildren(List)
  - setChildren
```
public void setChildren(java.util.List<? extends Tree> childTreesList)
```
    Set the children of this tree node to the given list. This method is implemented in the Tree class by converting the List into a tree array and calling the array-based method. Subclasses which use a List-based representation of tree children should override this method. This implementation allows the case that the List is null: it yields a node with no children (represented by a canonical zero-length children() array).
    
    Parameters:
    
    childTreesList - A list of trees to become children of the node. This method does not retain the List that you pass it (copying is done), but it will retain the individual children (they are not copied).
    
    See Also:
    
    setChildren(Tree[])
  - label
```
public Label label()
```
    Returns the label associated with the current node, or null if there is no label. The default implementation always returns null.
    
    Specified by:
    
    label in interface Labeled
    
    Returns:
    
    The label of the node
  - setLabel
```
public void setLabel(Label label)
```
    Sets the label associated with the current node, if there is one. The default implementation ignores the label.
    
    Specified by:
    
    setLabel in interface Labeled
    
    Parameters:
    
    label - The label
  - score
```
public double score()
```
    Returns the score associated with the current node, or NaN if there is no score. The default implementation returns NaN.
    
    Specified by:
    
    score in interface Scored
    
    Returns:
    
    The score
  - setScore
```
public void setScore(double score)
```
    Sets the score associated with the current node, if there is one.
    
    Parameters:
    
    score - The score
  - firstChild
```
public Tree firstChild()
```
    Returns the first child of a tree, or null if none.
    
    Returns:
    
    The first child
  - lastChild
```
public Tree lastChild()
```
    Returns the last child of a tree, or null if none.
    
    Returns:
    
    The last child
  - upperMostUnary
```
public Tree upperMostUnary(Tree root)
```
    Return the highest node of the (perhaps trivial) unary chain that this node is part of. In case this node is the only child of its parent, trace up the chain of unaries, and return the uppermost node of the chain (the node whose parent has multiple children, or the node that is the root of the tree).
    
    Parameters:
    
    root - The root of the tree that contains this subtree
    
    Returns:
    
    The uppermost node of the unary chain, if this node is in a unary chain, or else the current node
  - setSpans
```
public void setSpans()
```
    Assign a SpanAnnotation on each node of this tree. The index starts at zero.
  - getSpan
```
public IntPair getSpan()
```
    Returns SpanAnnotation of this node, or null if annotation is not assigned. Use setSpans() to assign SpanAnnotations to a tree.
    
    Returns:
    
    an IntPair: the SpanAnnotation of this node.
  - constituents
```
public java.util.Set<Constituent> constituents()
```
    Returns the Constituents generated by the parse tree. Constituents are computed with respect to whitespace (e.g., at the word level).
    
    Returns:
    
    a Set of the constituents as constituents of type Constituent
  - constituents
```
public java.util.Set<Constituent> constituents(ConstituentFactory cf)
```
    Returns the Constituents generated by the parse tree. The Constituents of a sentence include the preterminal categories but not the leaves.
    
    Parameters:
    
    cf - ConstituentFactory used to build the Constituent objects
    
    Returns:
    
    a Set of the constituents as SimpleConstituent type (in the current implementation, a HashSet
  - constituents
```
public java.util.Set<Constituent> constituents(ConstituentFactory cf,
                                               int maxDepth)
```
    Returns the Constituents generated by the parse tree. The Constituents of a sentence include the preterminal categories but not the leaves.
    
    Parameters:
    
    cf - ConstituentFactory used to build the Constituent objects
    
    maxDepth - The maximum depth at which to add constituents, where 0 is the root level. Negative maxDepth indicates no maximum.
    
    Returns:
    
    a Set of the constituents as SimpleConstituent type (in the current implementation, a HashSet
  - constituents
```
public java.util.Set<Constituent> constituents(ConstituentFactory cf,
                                               boolean charLevel)
```
    Returns the Constituents generated by the parse tree. The Constituents of a sentence include the preterminal categories but not the leaves.
    
    Parameters:
    
    cf - ConstituentFactory used to build the Constituent objects
    
    charLevel - If true, compute bracketings irrespective of whitespace boundaries.
    
    Returns:
    
    a Set of the constituents as SimpleConstituent type (in the current implementation, a HashSet
  - constituents
```
public java.util.Set<Constituent> constituents(ConstituentFactory cf,
                                               boolean charLevel,
                                               java.util.function.Predicate<Tree> filter)
```
  - localTree
```
public Tree localTree()
```
    Returns a new Tree that represents the local Tree at a certain node. That is, it builds a new tree that copies the mother and daughter nodes (but not their Labels), as non-Leaf nodes, but zeroes out their children.
    
    Returns:
    
    A local tree
  - localTrees
```
public java.util.Set<Tree> localTrees()
```
    Returns a set of one level Trees that ares the local trees of the tree. That is, it builds a new tree that copies the mother and daughter nodes (but not their Labels), for each phrasal node, but zeroes out their children.
    
    Returns:
    
    A set of local tree
  - toStringBuilder
```
public java.lang.StringBuilder toStringBuilder(java.lang.StringBuilder sb)
```
    Appends the printed form of a parse tree (as a bracketed String) to a StringBuilder. The implementation of this may be more efficient than for toString() on complex trees.
    
    Parameters:
    
    sb - The StringBuilder to which the tree will be appended
    
    Returns:
    
    Returns the StringBuilder passed in with extra stuff in it
  - updateBrackets
```
public static java.lang.String updateBrackets(java.lang.String text)
```
  - toStringBuilder
```
public java.lang.StringBuilder toStringBuilder(java.lang.StringBuilder sb,
                                               java.util.function.Function<Label,java.lang.String> labelFormatter)
```
    Appends the printed form of a parse tree (as a bracketed String) to a StringBuilder. The implementation of this may be more efficient than for toString() on complex trees.
    
    Parameters:
    
    sb - The StringBuilder to which the tree will be appended
    
    labelFormatter - Formatting routine for how to print a Label
    
    Returns:
    
    Returns the StringBuilder passed in with extra stuff in it
  - toString
```
public java.lang.String toString()
```
    Converts parse tree to string in Penn Treebank format. Implementation note: Internally, the method gains efficiency by chaining use of a single StringBuilder through all the printing.
    
    Specified by:
    
    toString in interface Label
    
    Overrides:
    
    toString in class java.util.AbstractCollection<Tree>
    
    Returns:
    
    the tree as a bracketed list on one line
  - printLocalTree
```
public void printLocalTree()
```
  - printLocalTree
```
public void printLocalTree(java.io.PrintWriter pw)
```
    Only prints the local tree structure, does not recurse
  - indentedListPrint
```
public void indentedListPrint()
```
    Indented list printing of a tree. The tree is printed in an indented list notation, with node labels followed by node scores.
  - indentedListPrint
```
public void indentedListPrint(java.io.PrintWriter pw,
                              boolean printScores)
```
    Indented list printing of a tree. The tree is printed in an indented list notation, with node labels followed by node scores.
    
    Parameters:
    
    pw - The PrintWriter to print the tree to
    
    printScores - Whether to print the scores (log probs) of tree nodes
  - indentedXMLPrint
```
public void indentedXMLPrint()
```
    Indented xml printing of a tree. The tree is printed in an indented xml notation.
  - indentedXMLPrint
```
public void indentedXMLPrint(java.io.PrintWriter pw,
                             boolean printScores)
```
    Indented xml printing of a tree. The tree is printed in an indented xml notation, with node labels followed by node scores.
    
    Parameters:
    
    pw - The PrintWriter to print the tree to
    
    printScores - Whether to print the scores (log probs) of tree nodes
  - nodeString
```
public java.lang.String nodeString()
```
    Returns the value of the node's label as a String. This is done by calling toString() on the value, if it exists. Otherwise, an empty string is returned.
    
    Returns:
    
    The label of a tree node as a String
  - pennPrint
```
public void pennPrint(java.io.PrintWriter pw)
```
    Print the tree as done in Penn Treebank merged files. The formatting should be exactly the same, but we don't print the trailing whitespace found in Penn Treebank trees. The basic deviation from a bracketed indented tree is to in general collapse the printing of adjacent preterminals onto one line of tags and words. Additional complexities are that conjunctions (tag CC) are not collapsed in this way, and that the unlabeled outer brackets are collapsed onto the same line as the next bracket down.
    
    Parameters:
    
    pw - The tree is printed to this PrintWriter
  - pennPrint
```
public void pennPrint(java.io.PrintWriter pw,
                      java.util.function.Function<Label,java.lang.String> labelFormatter)
```
  - pennPrint
```
public void pennPrint(java.io.PrintStream ps)
```
    Print the tree as done in Penn Treebank merged files. The formatting should be exactly the same, but we don't print the trailing whitespace found in Penn Treebank trees. The basic deviation from a bracketed indented tree is to in general collapse the printing of adjacent preterminals onto one line of tags and words. Additional complexities are that conjunctions (tag CC) are not collapsed in this way, and that the unlabeled outer brackets are collapsed onto the same line as the next bracket down.
    
    Parameters:
    
    ps - The tree is printed to this PrintStream
  - pennPrint
```
public void pennPrint(java.io.PrintStream ps,
                      java.util.function.Function<Label,java.lang.String> labelFormatter)
```
  - pennString
```
public java.lang.String pennString()
```
    Calls pennPrint() and saves output to a String
    
    Returns:
    
    The indent S-expression representation of a Tree
  - spanString
```
public java.lang.String spanString()
```
    Return String of leaves spanned by this tree assuming they are CoreLabel's Throws an IllegalArgumentException if the leaves are not CoreLabels that contain text info as in the typical use case of a Tree generated by a pipeline
    
    Returns:
    
    The text of the span of this Tree
  - pennPrint
```
public void pennPrint()
```
    Print the tree as done in Penn Treebank merged files. The formatting should be exactly the same, but we don't print the trailing whitespace found in Penn Treebank trees. The tree is printed to System.out. The basic deviation from a bracketed indented tree is to in general collapse the printing of adjacent preterminals onto one line of tags and words. Additional complexities are that conjunctions (tag CC) are not collapsed in this way, and that the unlabeled outer brackets are collapsed onto the same line as the next bracket down.
  - depth
```
public int depth()
```
    Finds the depth of the tree. The depth is defined as the length of the longest path from this node to a leaf node. Leaf nodes have depth zero. POS tags have depth 1. Phrasal nodes have depth >= 2.
    
    Returns:
    
    the depth
  - depth
```
public int depth(Tree node)
```
    Finds the distance from this node to the specified node. return -1 if this is not an ancestor of node.
    
    Parameters:
    
    node - A subtree contained in this tree
    
    Returns:
    
    the depth
  - headTerminal
```
public Tree headTerminal(HeadFinder hf,
                         Tree parent)
```
    Returns the tree leaf that is the head of the tree.
    
    Parameters:
    
    hf - The head-finding algorithm to use
    
    parent - The parent of this tree
    
    Returns:
    
    The head tree leaf if any, else null
  - headTerminal
```
public Tree headTerminal(HeadFinder hf)
```
    Returns the tree leaf that is the head of the tree.
    
    Parameters:
    
    hf - The headfinding algorithm to use
    
    Returns:
    
    The head tree leaf if any, else null
  - headPreTerminal
```
public Tree headPreTerminal(HeadFinder hf)
```
    Returns the preterminal tree that is the head of the tree. See isPreTerminal() for the definition of a preterminal node. Beware that some tree nodes may have no preterminal head.
    
    Parameters:
    
    hf - The headfinding algorithm to use
    
    Returns:
    
    The head preterminal tree, if any, else null
    
    Throws:
    
    java.lang.IllegalArgumentException - if called on a leaf node
  - percolateHeadAnnotations
```
public void percolateHeadAnnotations(HeadFinder hf)
```
    Finds the head words of each tree and assigns HeadWordLabelAnnotation on each node pointing to the correct CoreLabel. This relies on the nodes being CoreLabels, so it throws an IllegalArgumentException if this is ever not true.
  - percolateHeads
```
public void percolateHeads(HeadFinder hf)
```
    Finds the heads of the tree. This code assumes that the label does store and return sensible values for the category, word, and tag. It will be a no-op otherwise. The tree is modified. The routine assumes the Tree has word leaves and tag preterminals, and copies their category to word and tag respectively, if they have a null value.
    
    Parameters:
    
    hf - The headfinding algorithm to use
  - dependencies
```
public java.util.Set<Dependency<Label,Label,java.lang.Object>> dependencies()
```
    Return a Set of TaggedWord-TaggedWord dependencies, represented as Dependency objects, for the Tree. This will only give useful results if the internal tree node labels support HasWord and HasTag, and head percolation has already been done (see percolateHeads()).
    
    Returns:
    
    Set of dependencies (each a Dependency)
  - dependencies
```
public java.util.Set<Dependency<Label,Label,java.lang.Object>> dependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f)
```
  - dependencies
```
public java.util.Set<Dependency<Label,Label,java.lang.Object>> dependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f,
                                                                            boolean isConcrete,
                                                                            boolean copyLabel,
                                                                            boolean copyPosTag)
```
    Return a set of TaggedWord-TaggedWord dependencies, represented as Dependency objects, for the Tree. This will only give useful results if the internal tree node labels support HasWord and head percolation has already been done (see percolateHeads()).
    
    Parameters:
    
    f - Dependencies are excluded for which the Dependency is not accepted by the Filter
    
    Returns:
    
    Set of dependencies (each a Dependency)
  - mapDependencies
```
public java.util.Set<Dependency<Label,Label,java.lang.Object>> mapDependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f,
                                                                               HeadFinder hf)
```
    Return a set of Label-Label dependencies, represented as Dependency objects, for the Tree. The Labels are the ones of the leaf nodes of the tree, without mucking with them.
    
    Parameters:
    
    f - Dependencies are excluded for which the Dependency is not accepted by the Filter
    
    hf - The HeadFinder to use to identify the head of constituents. The code assumes that it can use headPreTerminal(hf) to find a tag and word to make a CoreLabel.
    
    Returns:
    
    Set of dependencies (each a Dependency between two CoreLabels, which each contain a tag(), word(), and value(), the last two of which are identical).
  - mapDependencies
```
public java.util.Set<Dependency<Label,Label,java.lang.Object>> mapDependencies(java.util.function.Predicate<Dependency<Label,Label,java.lang.Object>> f,
                                                                               HeadFinder hf,
                                                                               java.lang.String rootName)
```
    Return a set of Label-Label dependencies, represented as Dependency objects, for the Tree. The Labels are the ones of the leaf nodes of the tree, without mucking with them. The head of the sentence is a dependent of a synthetic "root" label.
    
    Parameters:
    
    f - Dependencies are excluded for which the Dependency is not accepted by the Filter
    
    hf - The HeadFinder to use to identify the head of constituents. The code assumes that it can use headPreTerminal(hf) to find a tag and word to make a CoreLabel.
    
    rootName - Name of the root node.
    
    Returns:
    
    Set of dependencies (each a Dependency between two CoreLabels, which each contain a tag(), word(), and value(), the last two of which are identical).
  - yield
```
public java.util.ArrayList<Label> yield()
```
    Gets the yield of the tree. The Label of all leaf nodes is returned as a list ordered by the natural left to right order of the leaves. Null values, if any, are inserted into the list like any other value.
    
    Returns:
    
    a List of the data in the tree's leaves.
  - yield
```
public java.util.ArrayList<Label> yield(java.util.ArrayList<Label> y)
```
    Gets the yield of the tree. The Label of all leaf nodes is returned as a list ordered by the natural left to right order of the leaves. Null values, if any, are inserted into the list like any other value.
    Implementation notes: c. 2003: This has been rewritten to thread, so only one List is used. 2007: This method was duplicated to start to give type safety to Sentence. This method will now make a Word for any Leaf which does not itself implement HasWord, and put the Word into the Sentence, so the Sentence elements MUST implement HasWord.
    
    Parameters:
    
    y - The list in which the yield of the tree will be placed. Normally, this will be empty when the routine is called, but if not, the new yield is added to the end of the list.
    
    Returns:
    
    a List of the data in the tree's leaves.
  - yieldWords
```
public java.util.ArrayList<Word> yieldWords()
```
  - yieldWords
```
public java.util.ArrayList<Word> yieldWords(java.util.ArrayList<Word> y)
```
  - yieldHasWord
```
public <X extends HasWord> java.util.ArrayList<X> yieldHasWord()
```
  - yieldHasWord
```
public <X extends HasWord> java.util.ArrayList<X> yieldHasWord(java.util.ArrayList<X> y)
```
  - yield
```
public <T> java.util.List<T> yield(java.util.List<T> y)
```
    Gets the yield of the tree. The Label of all leaf nodes is returned as a list ordered by the natural left to right order of the leaves. Null values, if any, are inserted into the list like any other value. This has been rewritten to thread, so only one List is used.
    
    Parameters:
    
    y - The list in which the yield of the tree will be placed. Normally, this will be empty when the routine is called, but if not, the new yield is added to the end of the list.
    
    Returns:
    
    a List of the data in the tree's leaves.
  - taggedYield
```
public java.util.ArrayList<TaggedWord> taggedYield()
```
    Gets the tagged yield of the tree. The Label of all leaf nodes is returned as a list ordered by the natural left to right order of the leaves. Null values, if any, are inserted into the list like any other value.
    
    Returns:
    
    a List of the data in the tree's leaves.
  - labeledYield
```
public java.util.List<LabeledWord> labeledYield()
```
  - taggedYield
```
public <X extends java.util.List<TaggedWord>> X taggedYield(X ty)
```
    Gets the tagged yield of the tree -- that is, get the preterminals as well as the terminals. The Label of all leaf nodes is returned as a list ordered by the natural left to right order of the leaves. Null values, if any, are inserted into the list like any other value. This has been rewritten to thread, so only one List is used.
    Implementation note: when we summon up enough courage, this method will be changed to take and return a List<W extends TaggedWord>.
    
    Parameters:
    
    ty - The list in which the tagged yield of the tree will be placed. Normally, this will be empty when the routine is called, but if not, the new yield is added to the end of the list.
    
    Returns:
    
    a List of the data in the tree's leaves.
  - labeledYield
```
public java.util.List<LabeledWord> labeledYield(java.util.List<LabeledWord> ty)
```
  - taggedLabeledYield
```
public java.util.List<CoreLabel> taggedLabeledYield()
```
    Returns a List<CoreLabel> from the tree. These are a copy of the complete token representation that adds the tag as the tag and value.
    
    Returns:
    
    A tagged, labeled yield.
  - preTerminalYield
```
public java.util.List<Label> preTerminalYield()
```
    Gets the preterminal yield (i.e., tags) of the tree. All data in preterminal nodes is returned as a list ordered by the natural left to right order of the tree. Null values, if any, are inserted into the list like any other value. Pre-leaves are nodes of height 1.
    
    Returns:
    
    a List of the data in the tree's pre-leaves.
  - preTerminalYield
```
public java.util.List<Label> preTerminalYield(java.util.List<Label> y)
```
    Gets the preterminal yield (i.e., tags) of the tree. All data in preleaf nodes is returned as a list ordered by the natural left to right order of the tree. Null values, if any, are inserted into the list like any other value. Pre-leaves are nodes of height 1.
    
    Parameters:
    
    y - The list in which the preterminals of the tree will be placed. Normally, this will be empty when the routine is called, but if not, the new yield is added to the end of the list.
    
    Returns:
    
    a List of the data in the tree's pre-leaves.
  - getLeaves
```
public <T extends Tree> java.util.List<T> getLeaves()
```
    Gets the leaves of the tree. All leaves nodes are returned as a list ordered by the natural left to right order of the tree. Null values, if any, are inserted into the list like any other value.
    
    Returns:
    
    a List of the leaves.
  - getLeaves
```
public <T extends Tree> java.util.List<T> getLeaves(java.util.List<T> list)
```
    Gets the leaves of the tree.
    
    Parameters:
    
    list - The list in which the leaves of the tree will be placed. Normally, this will be empty when the routine is called, but if not, the new yield is added to the end of the list.
    
    Returns:
    
    a List of the leaves.
  - labels
```
public java.util.Collection<Label> labels()
```
    Get the set of all node and leaf Labels, null or otherwise, contained in the tree.
    
    Specified by:
    
    labels in interface Labeled
    
    Returns:
    
    the Collection (actually, Set) of all values in the tree.
  - setLabels
```
public void setLabels(java.util.Collection<Label> c)
```
    Description copied from interface: Labeled
    
    Sets the labels associated with this object.
    
    Specified by:
    
    setLabels in interface Labeled
    
    Parameters:
    
    c - The set of Label values
  - flatten
```
public Tree flatten()
```
    Return a flattened version of a tree. In many circumstances, this will just return the tree, but if the tree is something like a binarized version of a dependency grammar tree, then it will be flattened back to a dependency grammar tree representation. Formally, a node will be removed from the tree when: it is not a terminal or preterminal, and its label() is equal() to the label() of its parent, and all its children will then be promoted to become children of the parent (in the same position in the sequence of daughters.
    
    Returns:
    
    A flattened version of this tree.
  - flatten
```
public Tree flatten(TreeFactory tf)
```
    Return a flattened version of a tree. In many circumstances, this will just return the tree, but if the tree is something like a binarized version of a dependency grammar tree, then it will be flattened back to a dependency grammar tree representation. Formally, a node will be removed from the tree when: it is not a terminal or preterminal, and its label() is equal() to the label() of its parent, and all its children will then be promoted to become children of the parent (in the same position in the sequence of daughters. Note: In the current implementation, the tree structure is mainly duplicated, but the links between preterminals and terminals aren't.
    
    Parameters:
    
    tf - TreeFactory used to create tree structure for flattened tree
    
    Returns:
    
    A flattened version of this tree.
  - subTrees
```
public java.util.Set<Tree> subTrees()
```
    Get the set of all subtrees inside the tree by returning a tree rooted at each node. These are not copies, but all share structure. The tree is regarded as a subtree of itself. Note: If you only want to form this Set so that you can iterate over it, it is more efficient to simply use the Tree class's own iterator() method. This will iterate over the exact same elements (but perhaps/probably in a different order).
    
    Returns:
    
    the Set of all subtrees in the tree.
  - subTreeList
```
public java.util.List<Tree> subTreeList()
```
    Get the list of all subtrees inside the tree by returning a tree rooted at each node. These are not copies, but all share structure. The tree is regarded as a subtree of itself. Note: If you only want to form this Collection so that you can iterate over it, it is more efficient to simply use the Tree class's own iterator() method. This will iterate over the exact same elements (but perhaps/probably in a different order).
    
    Returns:
    
    the List of all subtrees in the tree.
  - subTrees
```
public <T extends java.util.Collection<Tree>> T subTrees(T n)
```
    Add the set of all subtrees inside a tree (including the tree itself) to the given Collection. Note: If you only want to form this Collection so that you can iterate over it, it is more efficient to simply use the Tree class's own iterator() method. This will iterate over the exact same elements (but perhaps/probably in a different order).
    
    Parameters:
    
    n - A collection of nodes to which the subtrees will be added.
    
    Returns:
    
    The collection parameter with the subtrees added.
  - deepCopy
```
public Tree deepCopy()
```
    Makes a deep copy of not only the Tree structure but of the labels as well. Uses the TreeFactory of the root node given by treeFactory(). Assumes that your labels give a non-null labelFactory(). (Added by Aria Haghighi.)
    
    Returns:
    
    A deep copy of the tree structure and its labels
  - deepCopy
```
public Tree deepCopy(TreeFactory tf)
```
    Makes a deep copy of not only the Tree structure but of the labels as well. The new tree will have nodes made by the given TreeFactory. Each Label is copied using the labelFactory() returned by the corresponding node's label. It assumes that your labels give non-null labelFactory. (Added by Aria Haghighi.)
    
    Parameters:
    
    tf - The TreeFactory used to make all nodes in the copied tree structure
    
    Returns:
    
    A Tree that is a deep copy of the tree structure and Labels of the original tree.
  - deepCopy
```
public Tree deepCopy(TreeFactory tf,
                     LabelFactory lf)
```
    Makes a deep copy of not only the Tree structure but of the labels as well. Each tree is copied with the given TreeFactory. Each Label is copied using the given LabelFactory. That is, the tree and label factories can transform the nature of the data representation.
    
    Parameters:
    
    tf - The TreeFactory used to make all nodes in the copied tree structure
    
    lf - The LabelFactory used to make all nodes in the copied tree structure
    
    Returns:
    
    A Tree that is a deep copy of the tree structure and Labels of the original tree.
  - treeSkeletonCopy
```
public Tree treeSkeletonCopy()
```
    Create a deep copy of the tree structure. The entire structure is recursively copied, but label data themselves are not cloned. The copy is built using a TreeFactory that will produce a Tree like the input one.
    
    Returns:
    
    A deep copy of the tree structure (but not its labels).
  - treeSkeletonCopy
```
public Tree treeSkeletonCopy(TreeFactory tf)
```
    Create a deep copy of the tree structure. The entire structure is recursively copied, but label data themselves are not cloned. By specifying an appropriate TreeFactory, this method can be used to change the type of a Tree.
    
    Parameters:
    
    tf - The TreeFactory to be used for creating the returned Tree
    
    Returns:
    
    A deep copy of the tree structure (but not its labels).
  - treeSkeletonConstituentCopy
```
public Tree treeSkeletonConstituentCopy()
```
    Returns a deep copy of everything but the leaf labels. The leaf labels are reused from the original tree. This is useful for cases such as the dependency converter, which wants to finish with the same labels in the dependencies as the parse tree.
  - treeSkeletonConstituentCopy
```
public Tree treeSkeletonConstituentCopy(TreeFactory tf,
                                        LabelFactory lf)
```
  - transform
```
public Tree transform(TreeTransformer transformer)
```
    Create a transformed Tree. The tree is traversed in a depth-first, left-to-right order, and the TreeTransformer is called on each node. It returns some Tree. The transformed tree has a new tree structure (i.e., a "deep copy" is done), but it will usually share its labels with the original tree.
    
    Parameters:
    
    transformer - The function that transforms tree nodes or subtrees
    
    Returns:
    
    a transformation of this Tree
  - transform
```
public Tree transform(TreeTransformer transformer,
                      TreeFactory tf)
```
    Create a transformed Tree. The tree is traversed in a depth-first, left-to-right order, and the TreeTransformer is called on each node. It returns some Tree. The transformed tree has a new tree structure (i.e., a deep copy of the structure of the tree is done), but it will usually share its labels with the original tree.
    
    Parameters:
    
    transformer - The function that transforms tree nodes or subtrees
    
    tf - The TreeFactory which will be used for creating new nodes for the returned Tree
    
    Returns:
    
    a transformation of this Tree
  - spliceOut
```
public Tree spliceOut(java.util.function.Predicate<Tree> nodeFilter)
```
    Creates a (partial) deep copy of the tree, where all nodes that the filter does not accept are spliced out. If the result is not a tree (that is, it's a forest), an empty root node is generated.
    
    Parameters:
    
    nodeFilter - a Filter method which returns true to mean keep this node, false to mean delete it
    
    Returns:
    
    a filtered copy of the tree
  - spliceOut
```
public Tree spliceOut(java.util.function.Predicate<Tree> nodeFilter,
                      TreeFactory tf)
```
    Creates a (partial) deep copy of the tree, where all nodes that the filter does not accept are spliced out. That is, the particular modes for which the Filter returns false are removed from the Tree, but those nodes' children are kept (assuming they pass the Filter, and they are added in the appropriate left-to-right ordering as new children of the parent node. If the root node is deleted, so that the result would not be a tree (that is, it's a forest), an empty root node is generated. If nothing is accepted, null is returned.
    
    Parameters:
    
    nodeFilter - a Filter method which returns true to mean keep this node, false to mean delete it
    
    tf - A TreeFactory for making new trees. Used if the root node is deleted.
    
    Returns:
    
    a filtered copy of the tree.
  - prune
```
public Tree prune(java.util.function.Predicate<Tree> filter)
```
    Creates a deep copy of the tree, where all nodes that the filter does not accept and all children of such nodes are pruned. If all of a node's children are pruned, that node is cut as well. A Filter can assume that it will not be called with a null argument.
    For example, the following code excises all PP nodes from a Tree:
    Filter f = new Filter { public boolean accept(Tree t) { return ! t.label().value().equals("PP"); } }; tree.prune(f);
    If the root of the tree is pruned, null will be returned.
    
    Parameters:
    
    filter - the filter to be applied
    
    Returns:
    
    a filtered copy of the tree, including the possibility of null if the root node of the tree is filtered
  - prune
```
public Tree prune(java.util.function.Predicate<Tree> filter,
                  TreeFactory tf)
```
    Creates a deep copy of the tree, where all nodes that the filter does not accept and all children of such nodes are pruned. If all of a node's children are pruned, that node is cut as well. A Filter can assume that it will not be called with a null argument.
    
    Parameters:
    
    filter - the filter to be applied
    
    tf - the TreeFactory to be used to make new Tree nodes if needed
    
    Returns:
    
    a filtered copy of the tree, including the possibility of null if the root node of the tree is filtered
  - skipRoot
```
public Tree skipRoot()
```
    Returns first child if this is unary and if the label at the current node is either "ROOT" or empty.
    
    Returns:
    
    The first child if this is unary and if the label at the current node is either "ROOT" or empty, else this
  - treeFactory
```
public abstract TreeFactory treeFactory()
```
    Return a TreeFactory that produces trees of the appropriate type.
    
    Returns:
    
    A factory to produce Trees
  - parent
```
public Tree parent()
```
    Return the parent of the tree node. This routine may return null meaning simply that the implementation doesn't know how to determine the parent node, rather than there is no such node.
    
    Returns:
    
    The parent Tree node or null
    
    See Also:
    
    parent(Tree)
  - parent
```
public Tree parent(Tree root)
```
    Return the parent of the tree node. This routine will traverse a tree (depth first) from the given root, and will correctly find the parent, regardless of whether the concrete class stores parents. It will only return null if this node is the root node, or if this node is not contained within the tree rooted at root.
    
    Parameters:
    
    root - The root node of the whole Tree
    
    Returns:
    
    the parent Tree node if any; else null
  - size
```
public int size()
```
    Returns the number of nodes the tree contains. This method implements the size() function required by the Collections interface. The size of the tree is the number of nodes it contains (of all types, including the leaf nodes and the root).
    
    Specified by:
    
    size in interface java.util.Collection<Tree>
    
    Specified by:
    
    size in class java.util.AbstractCollection<Tree>
    
    Returns:
    
    The size of the tree
    
    See Also:
    
    depth()
  - ancestor
```
public Tree ancestor(int height,
                     Tree root)
```
    Return the ancestor tree node height nodes up from the current node.
    
    Parameters:
    
    height - How many nodes up to go. A parameter of 0 means return this node, 1 means to return the parent node and so on.
    
    root - The root node that this Tree is embedded under
    
    Returns:
    
    The ancestor at height height. It returns null if it does not exist or the tree implementation does not keep track of parents
  - iterator
```
public java.util.Iterator<Tree> iterator()
```
    Returns an iterator over all the nodes of the tree. This method implements the iterator() method required by the Collections interface. It does a preorder (children after node) traversal of the tree. (A possible extension to the class at some point would be to allow different traversal orderings via variant iterators.)
    
    Specified by:
    
    iterator in interface java.lang.Iterable<Tree>
    
    Specified by:
    
    iterator in interface java.util.Collection<Tree>
    
    Specified by:
    
    iterator in class java.util.AbstractCollection<Tree>
    
    Returns:
    
    An iterator over the nodes of the tree
  - postOrderNodeList
```
public java.util.List<Tree> postOrderNodeList()
```
  - preOrderNodeList
```
public java.util.List<Tree> preOrderNodeList()
```
  - valueOf
```
public static Tree valueOf(java.lang.String str)
```
    This gives you a tree from a String representation (as a bracketed Tree, of the kind produced by toString(), pennPrint(), or as in the Penn Treebank). It's not the most efficient thing to do for heavy duty usage. The Tree returned is created by a LabeledScoredTreeReaderFactory. This means that "standard" normalizations (stripping functional categories, indices, empty nodes, and A-over-A nodes) will be done on it.
    
    Parameters:
    
    str - The tree as a bracketed list in a String.
    
    Returns:
    
    The Tree
    
    Throws:
    
    java.lang.RuntimeException - If Tree format is not valid
  - valueOf
```
public static Tree valueOf(java.lang.String str,
                           TreeReaderFactory trf)
```
    This gives you a tree from a String representation (as a bracketed Tree, of the kind produced by toString(), pennPrint(), or as in the Penn Treebank. It's not the most efficient thing to do for heavy duty usage.
    
    Parameters:
    
    str - The tree as a bracketed list in a String.
    
    trf - The TreeFactory used to make the new Tree
    
    Returns:
    
    The Tree
    
    Throws:
    
    java.lang.RuntimeException - If the Tree format is not valid
  - getChild
```
public Tree getChild(int i)
```
    Return the child at some daughter index. The children are numbered starting with an index of 0.
    
    Parameters:
    
    i - The daughter index
    
    Returns:
    
    The tree at that daughter index
  - removeChild
```
public Tree removeChild(int i)
```
    Destructively removes the child at some daughter index and returns it. Note that this method will throw an ArrayIndexOutOfBoundsException if the daughter index is too big for the list of daughters.
    
    Parameters:
    
    i - The daughter index
    
    Returns:
    
    The tree at that daughter index
  - addChild
```
public void addChild(int i,
                     Tree t)
```
    Adds the tree t at the index position among the daughters. Note that this method will throw an ArrayIndexOutOfBoundsException if the daughter index is too big for the list of daughters.
    
    Parameters:
    
    i - the index position at which to add the new daughter
    
    t - the new daughter
  - addChild
```
public void addChild(Tree t)
```
    Adds the tree t at the last index position among the daughters.
    
    Parameters:
    
    t - the new daughter
  - setChild
```
public Tree setChild(int i,
                     Tree t)
```
    Replaces the ith child of this with the tree t. Note that this method will throw an ArrayIndexOutOfBoundsException if the child index is too big for the list of children.
    
    Parameters:
    
    i - The index position at which to replace the child
    
    t - The new child
    
    Returns:
    
    The tree that was previously the ith d
  - dominates
```
public boolean dominates(Tree t)
```
    Returns true if this dominates the Tree passed in as an argument. Object equality (==) rather than .equals() is used to determine domination. t.dominates(t) returns false.
  - dominationPath
```
public java.util.List<Tree> dominationPath(Tree t)
```
    Returns the path of nodes leading down to a dominated node, including this and the dominated node itself. Returns null if t is not dominated by this. Object equality (==) is the relevant criterion. t.dominationPath(t) returns null.
  - pathNodeToNode
```
public java.util.List<Tree> pathNodeToNode(Tree t1,
                                           Tree t2)
```
    Given nodes t1 and t2 which are dominated by this node, returns a list of all the nodes on the path from t1 to t2, inclusive, or null if none found.
  - joinNode
```
public Tree joinNode(Tree t1,
                     Tree t2)
```
    Given nodes t1 and t2 which are dominated by this node, returns their "join node": the node j such that j dominates both t1 and t2, and every other node which dominates both t1 and t2 dominates j. In the special case that t1 dominates t2, return t1, and vice versa. Return null if no such node can be found.
  - cCommands
```
public boolean cCommands(Tree t1,
                         Tree t2)
```
    Given nodes t1 and t2 which are dominated by this node, returns true iff t1 c-commands t2. (A node c-commands its sister(s) and any nodes below its sister(s).)
  - siblings
```
public java.util.List<Tree> siblings(Tree root)
```
    Returns the siblings of this Tree node. The siblings are all children of the parent of this node except this node.
    
    Parameters:
    
    root - The root within which this tree node is contained
    
    Returns:
    
    The siblings as a list, an empty list if there are no siblings. The returned list is a modifiable new list structure, but contains the actual children.
  - insertDtr
```
public void insertDtr(Tree dtr,
                      int position)
```
    insert dtr after position existing daughters in this.
  - value
```
public java.lang.String value()
```
    Description copied from interface: Label
    
    Return a String representation of just the "main" value of this label.
    
    Specified by:
    
    value in interface Label
    
    Returns:
    
    the "value" of the label
  - setValue
```
public void setValue(java.lang.String value)
```
    Description copied from interface: Label
    
    Set the value for the label (if one is stored).
    
    Specified by:
    
    setValue in interface Label
    
    Parameters:
    
    value - - the value for the label
  - setFromString
```
public void setFromString(java.lang.String labelStr)
```
    Description copied from interface: Label
    
    Set the contents of this label to this String representing the complete contents of the label. A class implementing label may throw an UnsupportedOperationException for this method (only). Typically, this method would do some appropriate decoding of the string in a way that sets multiple fields in an inverse of the toString() method.
    
    Specified by:
    
    setFromString in interface Label
    
    Parameters:
    
    labelStr - the String that translates into the content of the label
  - labelFactory
```
public LabelFactory labelFactory()
```
    Returns a factory that makes labels of the same type as this one. May return null if no appropriate factory is known.
    
    Specified by:
    
    labelFactory in interface Label
    
    Returns:
    
    the LabelFactory for this kind of label
  - leftCharEdge
```
public int leftCharEdge(Tree node)
```
    Returns the positional index of the left edge of node within the tree, as measured by characters. Returns -1 if node is not found. Note: These methods were written for internal evaluation routines. They are not the right methods to relate tree nodes to textual offsets. For these, look at the appropriate annotations on a CoreLabel (CharacterOffsetBeginAnnotation, etc.).
  - rightCharEdge
```
public int rightCharEdge(Tree node)
```
    Returns the positional index of the right edge of node within the tree, as measured by characters. Returns -1 if node is not found. rightCharEdge returns the index of the rightmost character + 1, so that rightCharEdge(getLeaves().get(i)) == leftCharEdge(getLeaves().get(i+1)) Note: These methods were written for internal evaluation routines. They are not the right methods to relate tree nodes to textual offsets. For these, look at the appropriate annotations on a CoreLabel (CharacterOffsetBeginAnnotation, etc.).
    
    Parameters:
    
    node - The subtree to look for in this Tree
    
    Returns:
    
    The positional index of the right edge of node
  - nodeNumber
```
public int nodeNumber(Tree root)
```
    Calculates the node's number, defined as the number of nodes traversed in a left-to-right, depth-first search of the tree starting at root and ending at this. Returns -1 if root does not contain this.
    
    Parameters:
    
    root - the root node of the relevant tree
    
    Returns:
    
    the number of the current node, or -1 if root does not contain this.
  - getNodeNumber
```
public Tree getNodeNumber(int i)
```
    Fetches the ith node in the tree, with node numbers defined as in nodeNumber(Tree).
    
    Parameters:
    
    i - the node number to fetch
    
    Returns:
    
    the ith node in the tree
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if i is not between 1 and the number of nodes (inclusive) contained in this.
  - indexLeaves
```
public void indexLeaves()
```
    Assign sequential integer indices to the leaves of the tree rooted at this Tree, starting with 1. The leaves are traversed from left to right. If the node is already indexed, then it uses the existing index. This will only work if the leaves extend CoreMap.
  - indexLeaves
```
public void indexLeaves(boolean overWrite)
```
    Index the leaves, and optionally overwrite existing IndexAnnotations if they exist.
    
    Parameters:
    
    overWrite - Whether to replace an existing index for a leaf.
  - indexLeaves
```
public int indexLeaves(int startIndex,
                       boolean overWrite)
```
    Assign sequential integer indices to the leaves of the subtree rooted at this Tree, beginning with startIndex, and traversing the leaves from left to right. If node is already indexed, then it uses the existing index. This method only works if the labels of the tree implement CoreLabel!
    
    Parameters:
    
    startIndex - index for this node
    
    overWrite - Whether to replace an existing index for a leaf.
    
    Returns:
    
    the next index still unassigned
  - percolateHeadIndices
```
public void percolateHeadIndices()
```
    Percolates terminal indices through a dependency tree. The terminals should be indexed, e.g., by calling indexLeaves() on the tree.
    This method assumes CoreLabels!
  - indexSpans
```
public void indexSpans()
```
    Index all spans (constituents) in the tree. For this, spans uses 0-based indexing and the span records the fencepost to the left of the first word and after the last word of the span. The spans are only recorded if the Tree has labels of a class which extends CoreMap.
  - indexSpans
```
public void indexSpans(int startIndex)
```
  - indexSpans
```
public Pair<java.lang.Integer,java.lang.Integer> indexSpans(MutableInteger startIndex)
```
    Assigns span indices (BeginIndexAnnotation and EndIndexAnnotation) to all nodes in a tree. The beginning index is equivalent to the IndexAnnotation of the first leaf in the constituent. The end index is equivalent to the first integer after the IndexAnnotation of the last leaf in the constituent.
    
    Parameters:
    
    startIndex - Begin indexing at this value

Class Tree

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Field Detail

EMPTY_TREE_ARRAY

Constructor Detail

Tree

Method Detail

isLeaf

numChildren

isUnaryRewrite

isPreTerminal

isPrePreTerminal

isPhrasal

isBinary

isBinarized

equals

hashCode

objectIndexOf

children

getChildrenAsList

setChildren

setChildren

label

setLabel

score

setScore

firstChild

lastChild

upperMostUnary

setSpans

getSpan

constituents

constituents

constituents

constituents

constituents

localTree

localTrees

toStringBuilder

updateBrackets

toStringBuilder

toString

printLocalTree

printLocalTree

indentedListPrint

indentedListPrint

indentedXMLPrint

indentedXMLPrint

nodeString

pennPrint

pennPrint

pennPrint

pennPrint

pennString

spanString

pennPrint

depth

depth

headTerminal

headTerminal

headPreTerminal

percolateHeadAnnotations

percolateHeads

dependencies

dependencies

dependencies

mapDependencies

mapDependencies

yield

yield

yieldWords

yieldWords

yieldHasWord

yieldHasWord