com.singularsys.jep.walkers
Class DoNothingVisitor

java.lang.Object
  com.singularsys.jep.walkers.DoNothingVisitor

All Implemented Interfaces:

JepComponent, ParserVisitor, java.io.Serializable

Direct Known Subclasses:

DeepCopyVisitor, SubstitutionVisitor

public class DoNothingVisitor
extends java.lang.Object
implements ParserVisitor, JepComponent

A Visitor which visits each node of a expression tree and does nothing. This visitor is intended as a base class for other visitors which manipulate expressions.

This class will always leave the original expression intact, but may reuse unchanged parts of the expression.

Since:

3.3 number of children no longer needs to be the same

Author:

Rich Morris Created on 16-Nov-2003

See Also:

Serialized Form

Field Summary

protected FunctionTable	ft
protected Jep	jep
protected NodeFactory	nf
protected OperatorTableI	ot
protected VariableTable	vt

Constructor Summary

DoNothingVisitor()

DoNothingVisitor(Jep j)

Method Summary

protected Node	copyChildrenIfNeeded(Node node, Node[] children) Sets the children of a node if they have changed for it current children.
FunctionTable	getFunctionTable()
JepComponent	getLightWeightInstance() Gets a light-weight instance suitable for using in multiple threads.
NodeFactory	getNodeFactory()
OperatorTableI	getOperatorTable()
VariableTable	getVariableTable()
void	init(Jep j) Initialize the component.
java.lang.Object	visit(ASTConstant node, java.lang.Object data) Visit a constant node.
java.lang.Object	visit(ASTFunNode node, java.lang.Object data) Visit a function node.
java.lang.Object	visit(ASTOpNode node, java.lang.Object data) Visit a operator node.
java.lang.Object	visit(ASTVarNode node, java.lang.Object data) Visit a variable node.
Node	visit(Node node)
protected Node[]	visitChildren(Node node, java.lang.Object data) Gets the result of visiting children of a array of nodes.
Node	visitNode(Node node, java.lang.Object data) Used to recursively visit the children of a node.

Methods inherited from class java.lang.Object

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

Field Detail

jep

protected Jep jep

nf

protected NodeFactory nf

vt

protected VariableTable vt

ft

protected FunctionTable ft

ot

protected OperatorTableI ot

Constructor Detail

DoNothingVisitor

public DoNothingVisitor()

DoNothingVisitor

public DoNothingVisitor(Jep j)

Method Detail

getLightWeightInstance

public JepComponent getLightWeightInstance()

Description copied from interface: JepComponent

Gets a light-weight instance suitable for using in multiple threads.

Specified by:

getLightWeightInstance in interface JepComponent

Returns:

this

init

public void init(Jep j)

Description copied from interface: JepComponent

Initialize the component. This methods is called whenever a component is added to Jep. Hence it allows components to keep track of the other components they may rely on.

Specified by:

init in interface JepComponent

Parameters:

j - the current Jep instance

visit

public Node visit(Node node)
           throws JepException

Throws:

JepException

visitNode

public Node visitNode(Node node,
                      java.lang.Object data)
               throws JepException

Used to recursively visit the children of a node.

Parameters:

node - Node to visit

data - user specified data

Returns:

a Node with the modified tree

Throws:

JepException

visitChildren

protected Node[] visitChildren(Node node,
                               java.lang.Object data)
                        throws JepException

Gets the result of visiting children of a array of nodes.

Parameters:

node - current node being visited

data - user specified data

Returns:

an array of results from visiting each child of the node.

Throws:

JepException

visit

public java.lang.Object visit(ASTConstant node,
                              java.lang.Object data)
                       throws JepException

Visit a constant node. Can be overridden buy sub-classes.

Specified by:

visit in interface ParserVisitor

Throws:

JepException

visit

public java.lang.Object visit(ASTVarNode node,
                              java.lang.Object data)
                       throws JepException

Visit a variable node. Can be overridden buy sub-classes.

Specified by:

visit in interface ParserVisitor

Throws:

JepException

visit

public java.lang.Object visit(ASTFunNode node,
                              java.lang.Object data)
                       throws JepException

Visit a function node. Can be overridden by sub-classes.

Specified by:

visit in interface ParserVisitor

Throws:

JepException

visit

public java.lang.Object visit(ASTOpNode node,
                              java.lang.Object data)
                       throws JepException

Visit a operator node. Can be overridden by sub-classes.

Specified by:

visit in interface ParserVisitor

Throws:

JepException

copyChildrenIfNeeded

protected Node copyChildrenIfNeeded(Node node,
                                    Node[] children)
                             throws JepException

Sets the children of a node if they have changed for it current children.

Throws:

JepException

getNodeFactory

public NodeFactory getNodeFactory()

getOperatorTable

public OperatorTableI getOperatorTable()

getVariableTable

public VariableTable getVariableTable()

getFunctionTable

public FunctionTable getFunctionTable()