## org.codehaus.groovy.syntax
Class CSTNode

An abstract base class for nodes in the concrete syntax tree that is the result of parsing. Note that the CSTNode is inextricably linked with the Token in that every CSTNode has a Token as it's root.

see:
  antlr.Parser

see:
  Token

see:
  Reduction

see:
  Types

author:
  bob mcwhirter

author:
  Chris Poirier

version:
  $Id: CSTNode.java 7922 2007-09-04 01:42:57Z paulk $

Constructor Summary
`CSTNode()`

Method Summary
`CSTNode` | `add(CSTNode element)` Adds an element to the node.
`void` | `addChildrenOf(CSTNode of)` Adds all children of the specified node to this one.
`Reduction` | `asReduction()` Creates a `Reduction` from this node.
`boolean` | `canMean(int type)` Returns true if the node can be coerced to the specified type.
`int` | `children()` Returns the number of non-root elements in the node.
`CSTNode` | `get(int index)` Returns the specified element, or null.
`CSTNode` | `get(int index, boolean safe)` Returns the specified element, or null.
`String` | `getDescription()` Returns a description of the node.
`int` | `getMeaning()` Returns the meaning of this node.
`int` | `getMeaningAs(def types)` Returns the first matching meaning of the specified types.
`Token` | `getRoot()` Returns the root of the node.
`Token` | `getRoot(boolean safe)` Returns the root of the node.
`String` | `getRootText()` Returns the text of the root.
`int` | `getStartColumn()` Returns the starting column of the node.
`int` | `getStartLine()` Returns the starting line of the node.
`int` | `getType()` Returns the actual type of the node.
`boolean` | `hasChildren()` Returns the number of elements in the node (including root).
`boolean` | `isA(int type)` Returns true if the node's meaning matches the specified type.
`boolean` | `isAllOf(def types)` Returns true if the node's meaning matches all of the specified types.
`boolean` | `isAnExpression()` Returns true if the node is a complete expression.
`boolean` | `isEmpty()` Returns true if the node is completely empty (no root, even).
`boolean` | `isOneOf(def types)` Returns true if the node's meaning matches any of the specified types.
`void` | `markAsExpression()` Marks the node a complete expression.
`boolean` | `matches(int type)` Returns true if the node matches the specified type.
`boolean` | `matches(int type, int child1)` Returns true if the node and it's first child match the specified types.
`boolean` | `matches(int type, int child1, int child2)` Returns true if the node and it's first and second child match the specified types.
`boolean` | `matches(int type, int child1, int child2, int child3)` Returns true if the node and it's first three children match the specified types.
`boolean` | `matches(int type, int child1, int child2, int child3, int child4)` Returns true if the node an it's first four children match the specified types.
`CSTNode` | `set(int index, CSTNode element)` Sets an element node in at the specified index.
`CSTNode` | `setMeaning(int meaning)` Sets the meaning for this node (and it's root Token).
`int` | `size()` Returns the number of elements in the node (including root).
`String` | `toString()` Creates a `Reduction` from this node.
`void` | `write(PrintWriter writer)` Formats the node and writes it to the specified `Writer`.
`void` | `write(PrintWriter writer, String indent)` Formats the node and writes it to the specified `Writer`.

Constructor Detail

### CSTNode

    CSTNode()

Method Detail

### add

    public CSTNode add(CSTNode element)

  Adds an element to the node. Returns the element for convenience. Not all nodes support this operation!

### addChildrenOf

    public void addChildrenOf(CSTNode of)

  Adds all children of the specified node to this one. Not all nodes support this operation!

### asReduction

    public Reduction asReduction()

  Creates a `Reduction` from this node. Returns self if the node is already a `Reduction`.

### canMean

    public boolean canMean(int type)

  Returns true if the node can be coerced to the specified type.

### children

    public int children()

  Returns the number of non-root elements in the node.

### get

    public CSTNode get(int index)

  Returns the specified element, or null.

### get

    public CSTNode get(int index, boolean safe)

  Returns the specified element, or null.

### getDescription

    public String getDescription()

  Returns a description of the node.

### getMeaning

    public int getMeaning()

  Returns the meaning of this node. If the node isEmpty(), returns the type of Token.NULL.

### getMeaningAs

    public int getMeaningAs(def types)

  Returns the first matching meaning of the specified types. Returns Types.UNKNOWN if there are no matches.

### getRoot

    public Token getRoot()

  Returns the root of the node. By convention, all nodes have a Token as the first element (or root), which indicates the type of the node. May return null if the node `isEmpty()`.

### getRoot

    public Token getRoot(boolean safe)

  Returns the root of the node. By convention, all nodes have a Token as the first element (or root), which indicates the type of the node. May return null if the node `isEmpty()`.

### getRootText

    public String getRootText()

  Returns the text of the root. Uses `getRoot(true)` to get the root, so you will only receive null in return if the root token returns it.

### getStartColumn

    public int getStartColumn()

  Returns the starting column of the node. Returns -1 if not known.

### getStartLine

    public int getStartLine()

  Returns the starting line of the node. Returns -1 if not known.

### getType

    public int getType()

  Returns the actual type of the node. If the node isEmpty(), returns the type of Token.NULL.

### hasChildren

    public boolean hasChildren()

  Returns the number of elements in the node (including root).

### isA

    public boolean isA(int type)

  Returns true if the node's meaning matches the specified type.

### isAllOf

    public boolean isAllOf(def types)

  Returns true if the node's meaning matches all of the specified types.

### isAnExpression

    public boolean isAnExpression()

  Returns true if the node is a complete expression.

### isEmpty

    public boolean isEmpty()

  Returns true if the node is completely empty (no root, even).

### isOneOf

    public boolean isOneOf(def types)

  Returns true if the node's meaning matches any of the specified types.

### markAsExpression

    public void markAsExpression()

  Marks the node a complete expression. Not all nodes support this operation!

### matches

    public boolean matches(int type)

  Returns true if the node matches the specified type. Effectively a synonym for `isA()`. Missing nodes are Token.NULL.

### matches

    public boolean matches(int type, int child1)

  Returns true if the node and it's first child match the specified types. Missing nodes are Token.NULL.

### matches

    public boolean matches(int type, int child1, int child2)

  Returns true if the node and it's first and second child match the specified types. Missing nodes are Token.NULL.

### matches

    public boolean matches(int type, int child1, int child2, int child3)

  Returns true if the node and it's first three children match the specified types. Missing nodes are Token.NULL.

### matches

    public boolean matches(int type, int child1, int child2, int child3, int child4)

  Returns true if the node an it's first four children match the specified types. Missing nodes have type Types.NULL.

### set

    public CSTNode set(int index, CSTNode element)

  Sets an element node in at the specified index. Returns the element for convenience. Not all nodes support this operation!

### setMeaning

    public CSTNode setMeaning(int meaning)

  Sets the meaning for this node (and it's root Token). Not valid if the node isEmpty(). Returns the node, for convenience.

### size

    public int size()

  Returns the number of elements in the node (including root).

### toString

    public String toString()

  Creates a `Reduction` from this node. Returns self if the node is already a `Reduction`.

### write

    public void write(PrintWriter writer)

  Formats the node and writes it to the specified `Writer`.

### write

    void write(PrintWriter writer, String indent)

  Formats the node and writes it to the specified `Writer`. The indent is prepended to each output line, and is increased for each recursion.