Package com.singularsys.jep.walkers

Class GenericDoNothingVisitor<D>

java.lang.Object

com.singularsys.jep.walkers.GenericDoNothingVisitor<D>

Type Parameters:

D - the type of the data passed to the visit methods

All Implemented Interfaces:

GenericVisitor<Node,D,ParseException>, JepComponent, Serializable

Direct Known Subclasses:

GenericDeepCopyVisitor, OverloadResolver, SubstitutionVisitor

public class GenericDoNothingVisitor<D>
extends Object
implements GenericVisitor<Node,D,ParseException>, JepComponent

A Visitor which visits each node, typically return the original node. For function and operator nodes it visits the children, if any have changed a new node is created with the new children, otherwise the original node is returned. This allows visitors to modify trees and create a new tree This class should be extended by visitors which modify trees and creates a new tree.

Since:

Jep 4.1

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected FunctionTable	ft
protected NodeFactory	nf
protected OperatorTableI	ot

Constructor Summary

Constructors

Constructor	Description
GenericDoNothingVisitor()	Constructor to use as a JepComponent.

Method Summary

Modifier and Type	Method	Description
protected boolean	childrenHaveChanged(Node node, List<Node> children)	Tests if the children of a node have changed
protected Node	copyChildrenIfNeeded(ASTFunNode node, List<Node> children)	Sets the children of a node if they have changed from its current children.
protected Node	copyChildrenIfNeeded(ASTOpNode node, List<Node> children)
JepComponent	getLightWeightInstance()	Gets a light-weight instance suitable for using in multiple threads.
void	init(Jep jep)	Initialize the component.
ParseException	makeException(String message)	Create an Exception of the correct type.
Node	visit(ASTConstant node, D data)	Visit a constant node
Node	visit(ASTFunNode node, D data)	Visit a function node
Node	visit(ASTOpNode node, D data)	Visit an operator node
Node	visit(ASTVarNode node, D data)	Visit a variable node

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.singularsys.jep.GenericVisitor

makeException, visit, visitChildren

Field Details

nf

protected NodeFactory nf

ot

protected OperatorTableI ot

ft

protected FunctionTable ft

Constructor Details

GenericDoNothingVisitor

public GenericDoNothingVisitor()

Constructor to use as a JepComponent. init(Jep) must be called later.

Method Details

visit

public Node visit(ASTConstant node,
 D data)
           throws ParseException

Description copied from interface: GenericVisitor

Visit a constant node

Specified by:

visit in interface GenericVisitor<Node,D,ParseException>

Parameters:

node - current node

data - context data

Returns:

the result of visiting the node

Throws:

ParseException

visit

public Node visit(ASTFunNode node,
 D data)
           throws ParseException

Description copied from interface: GenericVisitor

Visit a function node

Specified by:

visit in interface GenericVisitor<Node,D,ParseException>

Parameters:

node - current node

data - context data

Returns:

the result of visiting the node

Throws:

ParseException

visit

public Node visit(ASTOpNode node,
 D data)
           throws ParseException

Description copied from interface: GenericVisitor

Visit an operator node

Specified by:

visit in interface GenericVisitor<Node,D,ParseException>

Parameters:

node - current node

data - context data

Returns:

the result of visiting the node

Throws:

ParseException

visit

public Node visit(ASTVarNode node,
 D data)
           throws ParseException

Description copied from interface: GenericVisitor

Visit a variable node

Specified by:

visit in interface GenericVisitor<Node,D,ParseException>

Parameters:

node - current node

data - context data

Returns:

the result of visiting the node

Throws:

ParseException

init

public void init(Jep jep)

Description copied from interface: JepComponent

Initialize the component. This method 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:

jep - the current Jep instance

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:

either a new instance, null or 'this'.

makeException

public ParseException makeException(String message)

Description copied from interface: GenericVisitor

Create an Exception of the correct type. A typical implementation is

@Override
public JepException makeException(String message) {
 return new JepException(message);
}

Specified by:

makeException in interface GenericVisitor<Node,D,ParseException>

Parameters:

message - error message

Returns:

an Exception

copyChildrenIfNeeded

protected Node copyChildrenIfNeeded(ASTFunNode node,
 List<Node> children)
                             throws ParseException

Sets the children of a node if they have changed from its current children. If all the children are the same as the current children of the node then return the node.

Throws:

ParseException

copyChildrenIfNeeded

protected Node copyChildrenIfNeeded(ASTOpNode node,
 List<Node> children)
                             throws ParseException

Throws:

ParseException

childrenHaveChanged

protected boolean childrenHaveChanged(Node node,
 List<Node> children)

Tests if the children of a node have changed

Parameters:

node - the original node

children - the new set of children.

Returns:

true if any child have changed, false otherwise