org.apache.jdo.impl.jdoql.tree
Class ConstantExpr

java.lang.Object
  antlr.BaseAST
      antlr.CommonAST
          org.apache.jdo.impl.jdoql.jdoqlc.JDOQLAST
              org.apache.jdo.impl.jdoql.tree.NodeImpl
                  org.apache.jdo.impl.jdoql.tree.Expr
                      org.apache.jdo.impl.jdoql.tree.ConstantExpr

All Implemented Interfaces:

antlr.collections.AST, java.lang.Cloneable, ConstantExpression, Expression, Node, java.io.Serializable

Direct Known Subclasses:

BooleanLiteralExpr, ByteLiteralExpr, CharLiteralExpr, DoubleLiteralExpr, FloatLiteralExpr, IntLiteralExpr, LongLiteralExpr, ShortLiteralExpr

public class ConstantExpr

extends Expr

implements ConstantExpression

This node represents a constant expression. Examples of constant expressions are BooleanLiteralExpression or ByteLiteralExpression. It does not have any children.

Author:

Michael Watzek

See Also:

Serialized Form

Field Summary

(package private) java.lang.Object

value

Fields inherited from class org.apache.jdo.impl.jdoql.tree.NodeImpl

children, clazz, msg, object, parent

Fields inherited from class org.apache.jdo.impl.jdoql.jdoqlc.JDOQLAST

column, line, typeInfo

Fields inherited from class antlr.CommonAST

Fields inherited from class antlr.BaseAST

down, right

Constructor Summary

	ConstantExpr() The noarg constructor is needed for ANTLR support and deserialization.
(package private)	ConstantExpr(int tokenType, java.lang.String tokenName, java.lang.Object value) This constructor is called by specialized nodes.
(package private)	ConstantExpr(java.lang.Object value) This constructor is called by the query tree instance.
	ConstantExpr(antlr.Token token) The noarg constructor is needed for ANTLR support.

Method Summary

void	arrive(NodeVisitor visitor) Delegates to the argument visitor.
java.lang.Object	getValue() Returns the value represented by this expression.
java.lang.Object	leave(NodeVisitor visitor, java.lang.Object[] results) Delegates to the argument visitor.
static ConstantExpr	newConstant(java.lang.Object value) Returns an instance of ConstantExpression.

Methods inherited from class org.apache.jdo.impl.jdoql.tree.NodeImpl

ASTToChildren, clone, getChildren, getJavaClass, getObject, getParent, getTokenType, setChildren, setObject, setParent, toString, walkNextChild

Methods inherited from class org.apache.jdo.impl.jdoql.jdoqlc.JDOQLAST

getColumn, getLine, getTypeInfo, initialize, initialize, initialize, setColumn, setLine, setTypeInfo, treeToString

Methods inherited from class antlr.CommonAST

getText, getType, initialize, setText, setType

Methods inherited from class antlr.BaseAST

addChild, decode, encode, equals, equalsList, equalsListPartial, equalsTree, equalsTreePartial, findAll, findAllPartial, getFirstChild, getNextSibling, getNumberOfChildren, getTokenNames, removeChildren, setFirstChild, setNextSibling, setVerboseStringConversion, toStringList, toStringTree, xmlSerialize, xmlSerializeNode, xmlSerializeRootClose, xmlSerializeRootOpen

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.jdo.jdoql.tree.Node

getChildren, getJavaClass, getObject, getParent, getTokenType, setObject, setParent, walkNextChild

Field Detail

value

java.lang.Object value

Constructor Detail

ConstantExpr

public ConstantExpr()

The noarg constructor is needed for ANTLR support and deserialization. The caller must make sure to set the ANTLR tree structure himself or, call setChildren optionally.

ConstantExpr

public ConstantExpr(antlr.Token token)

The noarg constructor is needed for ANTLR support. The caller must make sure to set the ANTLR tree structure himself or, call setChildren optionally.

ConstantExpr

ConstantExpr(int tokenType,
             java.lang.String tokenName,
             java.lang.Object value)

This constructor is called by specialized nodes. The caller must make sure to set the ANTLR tree structure himself or, call setChildren optionally.

Parameters:

tokenType - the token tpye

tokenName - the name of this node

ConstantExpr

ConstantExpr(java.lang.Object value)

This constructor is called by the query tree instance. It delegates to the super class constructor.

Parameters:

value - the value represented by this expression

Method Detail

newConstant

public static ConstantExpr newConstant(java.lang.Object value)

Returns an instance of ConstantExpression. This method handles null as a constant expression.

Parameters:

value - the object wrapped by the constant expression

Returns:

the constant expression

getValue

public java.lang.Object getValue()

Returns the value represented by this expression.

Specified by:

getValue in interface ConstantExpression

Returns:

the value

arrive

public void arrive(NodeVisitor visitor)

Delegates to the argument visitor.

Specified by:

arrive in interface Node

Overrides:

arrive in class NodeImpl

Parameters:

visitor - the node visitor

leave

public java.lang.Object leave(NodeVisitor visitor,
                              java.lang.Object[] results)

Delegates to the argument visitor.

Specified by:

leave in interface Node

Overrides:

leave in class NodeImpl

Parameters:

visitor - the node visitor

results - the result array

Returns:

the object returned by the visitor instance