org.codehaus.groovy.syntax
Class CSTNode

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

Direct Known Subclasses:

Reduction, Token

public abstract class CSTNode
extends 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.

Version:

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

Author:

bob mcwhirter, Chris Poirier

See Also:

Parser, Token, Reduction, Types

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.
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).
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.
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).
String	toString() Formats the node as a String and returns it.
void	write(PrintWriter writer) Formats the node and writes it to the specified Writer.
protected void	write(PrintWriter writer, 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 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 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 String toString()

Formats the node as a String and returns it.

Overrides:

toString in class Object

write

public void write(PrintWriter writer)

Formats the node and writes it to the specified Writer.

write

protected 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.