org.lsmp.djep.xjep
Class SubstitutionVisitor

java.lang.Object
  org.lsmp.djep.xjep.DoNothingVisitor
      org.lsmp.djep.xjep.SubstitutionVisitor

All Implemented Interfaces:

ParserVisitor

public class SubstitutionVisitor

extends DoNothingVisitor

Allows substution of a given variable with an expresion tree. Substitution is best done using the XJep.substitute method. For example

 XJepI xjep = ...;
 Node node = xjep.parse("x^2+x");
 Node sub = xjep.parse("sin(y)");
 Node res = xjep.substitute(node,"x",sub,xjep);
 

Will give the expresion "(sin(y))^2+sin(y)".

Author:

Rich Morris Created on 16-Nov-2003

Constructor Summary

SubstitutionVisitor()

Method Summary

Node	substitute(Node orig, java.lang.String[] names, Node[] replacements, XJep xjep) Substitutes all occurences of a set of variable var with a set of replacements.
Node	substitute(Node orig, java.lang.String name, Node replacement, XJep xjep) Substitutes all occurences of variable var with replacement.
java.lang.Object	visit(ASTVarNode node, java.lang.Object data)

Methods inherited from class org.lsmp.djep.xjep.DoNothingVisitor

acceptChildrenAsArray, visit, visit, visit, visit

Methods inherited from class java.lang.Object

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

Constructor Detail

SubstitutionVisitor

public SubstitutionVisitor()

Method Detail

substitute

public Node substitute(Node orig,
                       java.lang.String name,
                       Node replacement,
                       XJep xjep)
                throws ParseException

Substitutes all occurences of variable var with replacement. Does not do a DeepCopy.

Parameters:

orig - the expresion we wish to perform the substitution on

name - the name of the variable

replacement - the expression var is substituted for

Returns:

the tree with variable replace (does not do a DeepCopy)

Throws:

ParseException

substitute

public Node substitute(Node orig,
                       java.lang.String[] names,
                       Node[] replacements,
                       XJep xjep)
                throws ParseException

Substitutes all occurences of a set of variable var with a set of replacements. Does not do a DeepCopy.

Parameters:

orig - the expresion we wish to perform the substitution on

names - the names of the variable

replacements - the expression var is substituted for

Returns:

the tree with variable replace (does not do a DeepCopy)

Throws:

ParseException

visit

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

Specified by:

visit in interface ParserVisitor

Overrides:

visit in class DoNothingVisitor

Throws:

ParseException