com.singularsys.extensions.xjep

Class CommandVisitor

java.lang.Object

com.singularsys.jep.walkers.DoNothingVisitor

com.singularsys.extensions.xjep.CommandVisitor

All Implemented Interfaces:

JepComponent, ParserVisitor, java.io.Serializable

public class CommandVisitor
extends DoNothingVisitor

Executes commands like diff and eval embedded in expression trees. For example you could do

 eval(diff(x ^ 3, x), x, 2)
 

to differentiate x^3 and then substitute x=2 to get the value 12. To use do

 Jep j = ...; Node in = ...;
 TreeUtils tu = new TreeUtils(j);
 CommandVisitor cv = new CommandVisitor(tu);
 Node out = cv.process(in);
 

Commands to be executed must implement CommandVisitorI and PostfixMathCommandI. See ParserVisitor for details on the VisitorPattern.

Author:

R Morris Created on 19-Jun-2003

See Also:

Serialized Form

Field Summary

Fields inherited from class com.singularsys.jep.walkers.DoNothingVisitor

ft, jep, nf, ot, vt

Constructor Summary

Constructors

Constructor and Description
CommandVisitor()

Method Summary

Modifier and Type	Method and Description
Node	process(Node node) Descends the tree processing all diff, eval and simplify options
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.

Methods inherited from class com.singularsys.jep.walkers.DoNothingVisitor

childrenHaveChanged, copyChildrenIfNeeded, getFunctionTable, getLightWeightInstance, getNodeFactory, getOperatorTable, getVariableTable, init, visit, visit, visit, visitChildren, visitNode

Methods inherited from class java.lang.Object

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

Constructor Detail

CommandVisitor

public CommandVisitor()

Method Detail

process

public Node process(Node node)
             throws ParseException

Descends the tree processing all diff, eval and simplify options

Throws:

ParseException

visit

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

Description copied from class: DoNothingVisitor

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

Specified by:

visit in interface ParserVisitor

Overrides:

visit in class DoNothingVisitor

Throws:

JepException

visit

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

Description copied from class: DoNothingVisitor

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

Specified by:

visit in interface ParserVisitor

Overrides:

visit in class DoNothingVisitor

Throws:

JepException