All Superinterfaces:

Reportable

All Known Subinterfaces:

AntlrNode<N>, CommentNode, GenericNode<N>, JjtreeNode<N>, RootNode, ScopedNode, TextAvailableNode, TextNode

All Known Implementing Classes:

AbstractJjtreeNode, AbstractNode, BaseAntlrErrorNode, BaseAntlrInnerNode, BaseAntlrNode, BaseAntlrTerminalNode, PlainTextLanguage.PlainTextFile
```
public interface Node
extends Reportable
```
Root interface for all AST nodes. This interface provides only the API shared by all AST implementations in PMD language modules. This includes for now:
- Tree traversal methods: getParent(), getIndexInParent(), getChild(int), and getNumChildren(). These four basic operations are used to implement more specific traversal operations, like firstChild(Class), and NodeStreams.
- The API used to describe nodes in a form understandable by XPath expressions: getXPathNodeName(), getXPathAttributesIterator()
- Location metadata: getReportLocation()
- An extensible metadata store: getUserMap()
Every language implementation must publish a sub-interface of Node which serves as a supertype for all nodes of that language (e.g. pmd-java provides JavaNode, pmd-apex provides ApexNode, etc.). It is assumed in many places that the getChild(int) and getParent() method return an instance of this sub-interface. For example, no JSP node should have a Java node as its child. Embedding nodes from different languages will not be done via these methods, and conforming implementations should ensure that every node returned by these methods are indeed of the same type.

Field Summary

Fields
Modifier and Type Field Description

static Comparator<Node> COORDS_COMPARATOR
Compares nodes according to their location in the file.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default <P,R> R`	`acceptVisitor(AstVisitor<? super P,? extends R> visitor, P data)`	Calls back the visitor's visit method corresponding to the runtime type of this Node.
`default NodeStream<? extends Node>`	`ancestors()`	Returns a node stream containing all the strict ancestors of this node, in innermost to outermost order.
`default <R extends Node> NodeStream<R>`	`ancestors(Class<? extends R> rClass)`	Returns the ancestor stream of this node filtered by the given node type.
`default NodeStream<? extends Node>`	`ancestorsOrSelf()`	Returns a node stream containing this node and its ancestors.
`default NodeStream<? extends Node>`	`asStream()`	Returns a node stream containing only this node.
`default NodeStream<? extends Node>`	`children()`	Returns a node stream containing all the children of this node.
`default <R extends Node> NodeStream<R>`	`children(Class<? extends R> rClass)`	Returns a node stream of the children of this node that are of the given type.
`default int`	`compareLocation(Node other)`	Compare the coordinates of this node with the other one as if with `COORDS_COMPARATOR`.
`default NodeStream.DescendantNodeStream<? extends Node>`	`descendants()`	Returns a node stream containing all the descendants of this node.
`default <R extends Node> NodeStream.DescendantNodeStream<R>`	`descendants(Class<? extends R> rClass)`	Returns a node stream of the descendants of this node that are of the given type.
`default NodeStream.DescendantNodeStream<? extends Node>`	`descendantsOrSelf()`	Returns a node stream containing this node, then all its descendants.
`default <R extends Node> @Nullable R`	`firstChild(Class<? extends R> rClass)`	Returns the first child of this node that has the given type.
`default AstInfo<? extends RootNode>`	`getAstInfo()`	Returns the `AstInfo` for this root node.
`default int`	`getBeginColumn()`
`default int`	`getBeginLine()`
`Node`	`getChild(int index)`	Returns the child of this node at the given index.
`default int`	`getEndColumn()`
`default int`	`getEndLine()`
`default @Nullable Node`	`getFirstChild()`	Returns the first child of this node, or null if it doesn't exist.
`default String`	`getImage()`	Returns a string token, usually filled-in by the parser, which describes some textual characteristic of this node.
`int`	`getIndexInParent()`	Returns the index of this node in its parent's children.
`default LanguageVersion`	`getLanguageVersion()`	Returns the language version of this node.
`default @Nullable Node`	`getLastChild()`	Returns the first last of this node, or null if it doesn't exist.
`default @Nullable Node`	`getNextSibling()`	Returns the next sibling of this node, or null if it does not exist.
`int`	`getNumChildren()`	Returns the number of children of this node.
`Node`	`getParent()`	Returns the parent of this node, or null if this is the root of the tree.
`default @Nullable Node`	`getPreviousSibling()`	Returns the previous sibling of this node, or null if it does not exist.
`default FileLocation`	`getReportLocation()`	Returns the location at which this element should be reported.
`default @NonNull RootNode`	`getRoot()`	Returns the root of the tree this node is declared in.
`default @NonNull TextDocument`	`getTextDocument()`	Returns the text document from which this tree was parsed.
`TextRegion`	`getTextRegion()`	Returns a region of text delimiting the node in the underlying text document.
`DataMap<DataMap.DataKey<?,?>>`	`getUserMap()`	Returns a data map used to store additional information on this node.
`default Iterator<Attribute>`	`getXPathAttributesIterator()`	Returns an iterator enumerating all the attributes that are available from XPath for this node.
`String`	`getXPathNodeName()`	Gets the name of the node that is used to match it with XPath queries.
`default boolean`	`hasImageEqualTo(String image)`	Returns true if this node's image is equal to the given string.
`default boolean`	`isFindBoundary()`	Returns true if this node is considered a boundary by traversal methods.

- Field Detail
  - COORDS_COMPARATOR
```
static final Comparator<Node> COORDS_COMPARATOR
```
    Compares nodes according to their location in the file. Note that this comparator is not consistent with equals (see Comparator) as some nodes have the same location.
- Method Detail
  - getImage
```
default String getImage()
```
    Returns a string token, usually filled-in by the parser, which describes some textual characteristic of this node. This is usually an identifier, but you should check that using the Designer. On most nodes though, this method returns null.
    Note: This method will be deprecated in the future (#4787). It will be replaced with methods that have more specific names in node classes. In some cases, there are already alternatives available that should be used.
  - hasImageEqualTo
```
default boolean hasImageEqualTo(String image)
```
    Returns true if this node's image is equal to the given string.
    Note: This method will be deprecated in the future (#4787). See getImage().
    
    Parameters:
    
    image - The image to check
  - compareLocation
```
default int compareLocation(Node other)
```
    Compare the coordinates of this node with the other one as if with COORDS_COMPARATOR. The result is useless if both nodes are not from the same tree.
    
    Parameters:
    
    other - Other node
    
    Returns:
    
    A positive integer if this node comes AFTER the other, 0 if they have the same position, a negative integer if this node comes BEFORE the other
  - getReportLocation
```
default FileLocation getReportLocation()
```
    Returns the location at which this element should be reported.
    Use this instead of getBeginColumn()/getBeginLine(), etc. This is not necessarily the exact boundaries of the node in the text. Nodes that can provide exact position information do so using a TextRegion, by implementing TextAvailableNode.
    Use this instead of getBeginColumn()/getBeginLine(), etc.
    
    Specified by:
    
    getReportLocation in interface Reportable
  - getTextRegion
```
TextRegion getTextRegion()
```
    Returns a region of text delimiting the node in the underlying text document. This does not necessarily match the report location.
  - getBeginLine
```
default int getBeginLine()
```
  - getBeginColumn
```
default int getBeginColumn()
```
  - getEndLine
```
default int getEndLine()
```
  - getEndColumn
```
default int getEndColumn()
```
  - isFindBoundary
```
@NoAttribute
default boolean isFindBoundary()
```
    Returns true if this node is considered a boundary by traversal methods. Traversal methods such as descendants() don't look past such boundaries by default, which is usually the expected thing to do. For example, in Java, lambdas and nested classes are considered find boundaries.
    
    Returns:
    
    True if this node is a find boundary
    
    See Also:
    
    NodeStream.DescendantNodeStream.crossFindBoundaries(boolean)
  - getUserMap
```
DataMap<DataMap.DataKey<?,?>> getUserMap()
```
    Returns a data map used to store additional information on this node.
    
    Returns:
    
    The user data map of this node
    
    Since:
    
    6.22.0
  - getTextDocument
```
default @NonNull TextDocument getTextDocument()
```
    Returns the text document from which this tree was parsed. This means, that the whole file text is in memory while the AST is.
    
    Returns:
    
    The text document
  - getParent
```
Node getParent()
```
    Returns the parent of this node, or null if this is the root of the tree.
    
    Returns:
    
    The parent of this node
    
    Since:
    
    6.21.0
  - getChild
```
Node getChild(int index)
```
    Returns the child of this node at the given index.
    
    Throws:
    
    IndexOutOfBoundsException - if the index is negative or greater than getNumChildren().
    
    Since:
    
    6.21.0
  - getNumChildren
```
int getNumChildren()
```
    Returns the number of children of this node.
    
    Since:
    
    6.21.0
  - getIndexInParent
```
int getIndexInParent()
```
    Returns the index of this node in its parent's children. If this node is a root node, returns -1.
    
    Returns:
    
    The index of this node in its parent's children
    
    Since:
    
    6.21.0
  - acceptVisitor
```
default <P,R> R acceptVisitor(AstVisitor<? super P,? extends R> visitor,
                                    P data)
```
    Calls back the visitor's visit method corresponding to the runtime type of this Node. This should usually be preferred to calling a visit method directly (usually the only calls to those are in the implementations of this acceptVisitor method).
    
    Implementation Requirements:
    
    A typical implementation will check the type of the visitor to be that of the language specific visitor, then call the most specific visit method of this Node. This is typically implemented by having a different override per concrete node class (no shortcuts). The default implementation calls back AstVisitor.cannotVisit(Node, Object).
    
    Type Parameters:
    
    R - Return type of the visitor
    
    P - Parameter type of the visitor
    
    Parameters:
    
    visitor - Visitor to dispatch
    
    data - Parameter to the visit
    
    Returns:
    
    What the visitor returned. If this node doesn't recognize the type of the visitor, returns visitor.cannotVisit(this, data).
    
    Since:
    
    7.0.0
  - getAstInfo
```
default AstInfo<? extends RootNode> getAstInfo()
```
    Returns the AstInfo for this root node.
    
    Implementation Note:
    
    This default implementation can not work unless overridden in the root node.
  - getXPathNodeName
```
String getXPathNodeName()
```
    Gets the name of the node that is used to match it with XPath queries.
    
    Returns:
    
    The XPath node name
  - getXPathAttributesIterator
```
default Iterator<Attribute> getXPathAttributesIterator()
```
    Returns an iterator enumerating all the attributes that are available from XPath for this node.
    
    Returns:
    
    An attribute iterator for this node
    
    See Also:
    
    AttributeAxisIterator
  - getFirstChild
```
default @Nullable Node getFirstChild()
```
    Returns the first child of this node, or null if it doesn't exist.
    
    Since:
    
    7.0.0
  - getLastChild
```
default @Nullable Node getLastChild()
```
    Returns the first last of this node, or null if it doesn't exist.
    
    Since:
    
    7.0.0
  - getPreviousSibling
```
default @Nullable Node getPreviousSibling()
```
    Returns the previous sibling of this node, or null if it does not exist.
    
    Since:
    
    7.0.0
  - getNextSibling
```
default @Nullable Node getNextSibling()
```
    Returns the next sibling of this node, or null if it does not exist.
    
    Since:
    
    7.0.0
  - asStream
```
default NodeStream<? extends Node> asStream()
```
    Returns a node stream containing only this node. NodeStream.of(Node) is a null-safe version of this method.
    
    Returns:
    
    A node stream containing only this node
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.of(Node)
  - children
```
default NodeStream<? extends Node> children()
```
    Returns a node stream containing all the children of this node. This method does not provide much type safety, you'll probably want to use children(Class).
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.children(Class)
  - descendants
```
default NodeStream.DescendantNodeStream<? extends Node> descendants()
```
    Returns a node stream containing all the descendants of this node. See NodeStream.DescendantNodeStream for details.
    
    Returns:
    
    A node stream of the descendants of this node
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.descendants()
  - descendantsOrSelf
```
default NodeStream.DescendantNodeStream<? extends Node> descendantsOrSelf()
```
    Returns a node stream containing this node, then all its descendants. See NodeStream.DescendantNodeStream for details.
    
    Returns:
    
    A node stream of the whole subtree topped by this node
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.descendantsOrSelf()
  - ancestors
```
default NodeStream<? extends Node> ancestors()
```
    Returns a node stream containing all the strict ancestors of this node, in innermost to outermost order. The returned stream doesn't contain this node, and is empty if this node has no parent.
    
    Returns:
    
    A node stream of the ancestors of this node
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.ancestors()
  - ancestorsOrSelf
```
default NodeStream<? extends Node> ancestorsOrSelf()
```
    Returns a node stream containing this node and its ancestors. The nodes of the returned stream are yielded in a depth-first fashion.
    
    Returns:
    
    A stream of ancestors
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.ancestorsOrSelf()
  - children
```
default <R extends Node> NodeStream<R> children(Class<? extends R> rClass)
```
    Returns a node stream of the children of this node that are of the given type.
    
    Type Parameters:
    
    R - Type of node the returned stream should contain
    
    Parameters:
    
    rClass - Type of node the returned stream should contain
    
    Returns:
    
    A new node stream
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.children(Class)
  - firstChild
```
default <R extends Node> @Nullable R firstChild(Class<? extends R> rClass)
```
    Returns the first child of this node that has the given type. Returns null if no such child exists.
    If you want to process this element as a node stream, use asStream().firstChild(rClass) instead, which returns a node stream.
    
    Type Parameters:
    
    R - Type of the child to find
    
    Parameters:
    
    rClass - Type of the child to find
    
    Returns:
    
    A child, or null
    
    Since:
    
    7.0.0
  - descendants
```
default <R extends Node> NodeStream.DescendantNodeStream<R> descendants(Class<? extends R> rClass)
```
    Returns a node stream of the descendants of this node that are of the given type. See NodeStream.DescendantNodeStream for details.
    
    Type Parameters:
    
    R - Type of node the returned stream should contain
    
    Parameters:
    
    rClass - Type of node the returned stream should contain
    
    Returns:
    
    A new node stream
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.descendants(Class)
  - ancestors
```
default <R extends Node> NodeStream<R> ancestors(Class<? extends R> rClass)
```
    Returns the ancestor stream of this node filtered by the given node type.
    
    Type Parameters:
    
    R - Type of node the returned stream should contain
    
    Parameters:
    
    rClass - Type of node the returned stream should contain
    
    Returns:
    
    A new node stream
    
    Since:
    
    7.0.0
    
    See Also:
    
    NodeStream.ancestors(Class)
  - getRoot
```
default @NonNull RootNode getRoot()
```
    Returns the root of the tree this node is declared in.
    
    Since:
    
    7.0.0
  - getLanguageVersion
```
default LanguageVersion getLanguageVersion()
```
    Returns the language version of this node.

Interface Node

Field Summary

Method Summary

Field Detail

COORDS_COMPARATOR

Method Detail

getImage

hasImageEqualTo

compareLocation

getReportLocation

getTextRegion

getBeginLine

getBeginColumn

getEndLine

getEndColumn

isFindBoundary

getUserMap

getTextDocument

getParent

getChild

getNumChildren

getIndexInParent

acceptVisitor

getAstInfo

getXPathNodeName

getXPathAttributesIterator

getFirstChild

getLastChild

getPreviousSibling

getNextSibling

asStream

children

descendants

descendantsOrSelf

ancestors

ancestorsOrSelf

children

firstChild

descendants

ancestors

getRoot

getLanguageVersion