org.codehaus.groovy.syntax

## Class CSTNode

- java.lang.Object
- - org.codehaus.groovy.syntax.CSTNode

Direct Known Subclasses:
  Reduction, Token

    public abstract class CSTNode
    extends java.lang.Object

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.

Author:
  bob mcwhirter, Chris Poirier
See Also:
  `Parser`, `Token`, `Reduction`, `Types`

### Constructor Summary

Constructors
Constructor and Description
`CSTNode()`

### Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
`CSTNode` `add(CSTNode element)` Adds an element to the node.
`void` `addChildrenOf(CSTNode of)` Adds all children of the specified node to this one.
`abstract 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.
`abstract CSTNode` `get(int index)` Returns the specified element, or null.
`CSTNode` `get(int index, boolean safe)` Returns the specified element, or Token.NULL if safe is set and the specified element is null (or doesn't exist).
`java.lang.String` `getDescription()` Returns a description of the node.
`int` `getMeaning()` Returns the meaning of this node.
`int` `getMeaningAs(int[] types)` Returns the first matching meaning of the specified types.
`abstract Token` `getRoot()` Returns the root of the node.
`Token` `getRoot(boolean safe)` Returns the root of the node, the Token that indicates it's type.
`java.lang.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 true if the node has any non-root elements.
`boolean` `isA(int type)` Returns true if the node's meaning matches the specified type.
`boolean` `isAllOf(int[] 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(int[] types)` Returns true if the node's meaning matches any of the specified types.
`void` `markAsExpression()` Marks the node a complete expression.
`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).
`abstract int` `size()` Returns the number of elements in the node (including root).
`java.lang.String` `toString()` Formats the node as a `String` and returns it.
`void` `write(java.io.PrintWriter writer)` Formats the node and writes it to the specified `Writer`.
`protected void` `write(java.io.PrintWriter writer, java.lang.String indent)` Formats the node and writes it to the specified `Writer`.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

### Constructor Detail

#### CSTNode

    public CSTNode()

### Method Detail

#### getMeaning

    public int getMeaning()

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

#### 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.

#### getType

    public int getType()

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

#### canMean

    public boolean canMean(int type)

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

#### isA

    public boolean isA(int type)

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

#### isOneOf

    public boolean isOneOf(int[] types)

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

#### isAllOf

    public boolean isAllOf(int[] types)

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

#### getMeaningAs

    public int getMeaningAs(int[] types)

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

#### isEmpty

    public boolean isEmpty()

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

#### size

    public abstract int size()

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

#### hasChildren

    public boolean hasChildren()

Returns true if the node has any non-root elements.

#### children

    public int children()

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

#### get

    public abstract CSTNode get(int index)

Returns the specified element, or null.

#### get

    public CSTNode get(int index,
                       boolean safe)

Returns the specified element, or Token.NULL if safe is set and the specified element is null (or doesn't exist).

#### getRoot

    public abstract 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, the Token that indicates it's type. Returns a Token.NULL if safe and the actual root is null.

#### getRootText

    public java.lang.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.

#### getDescription

    public java.lang.String getDescription()

Returns a description of the node.

#### getStartLine

    public int getStartLine()

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

#### getStartColumn

    public int getStartColumn()

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

#### markAsExpression

    public void markAsExpression()

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

#### isAnExpression

    public boolean isAnExpression()

Returns true if the node is a complete expression.

#### 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!

#### 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!

#### asReduction

    public abstract Reduction asReduction()

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

#### toString

    public java.lang.String toString()

Formats the node as a `String` and returns it.

Overrides:
  `toString` in class `java.lang.Object`

#### write

    public void write(java.io.PrintWriter writer)

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

#### write

    protected void write(java.io.PrintWriter writer,
                         java.lang.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.