Package com.singularsys.jep.walkers

Class SerializableExpression

java.lang.Object

com.singularsys.jep.walkers.PostfixTreeWalker

com.singularsys.jep.walkers.SerializableExpression

All Implemented Interfaces:

Externalizable, Serializable

public class SerializableExpression
extends PostfixTreeWalker
implements Externalizable

A serializable representation of an expression. To serialize an expression use

 ObjectOutputStream oos = ...;
 SerializableExpression se = new SerializableExpression(node);
 oos.writeObject(se);
 

To deserialize use

 ObjectInputStream ois = ...;
 SerializableExpression se = (SerializableExpression) ois.readObject();
 Node n = se.toNode(jep);
 

Since Jep 4.0 this class will serialize any Hooks added to the nodes (see Node.HookKey). Expressions serialized in older versions of Jep can still be read by the Jep 4.0 version of this class. Expressions serialized by this version can be read by older version, provide no hooks are set. The HookRemover class can be used to remove any hooks.

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SerializableExpression.Constant	An element representing a constant value.
static interface	SerializableExpression.Element	interface used in internal representation of expression
static class	SerializableExpression.Function	An element representing a function.
static class	SerializableExpression.Operator	An element representing an operator.
static class	SerializableExpression.Variable	An element representing a variable.

Constructor Summary

Constructors

Constructor	Description
SerializableExpression()	Constructor used by the serializable mechanism.
SerializableExpression(Node node)	Construct a SerializableExpression from a given node

Method Summary

Modifier and Type	Method	Description
Iterator<SerializableExpression.Element>	iterator()	Returns an iterator for the reverse polish representation of the expression.
final void	readExternal(ObjectInput ois)
final Node	toNode(Jep j)	Convert to a node in a given context.
String	toString()
protected void	visit(ASTConstant node, int nchildren, int depth)	Visit a constant node
protected void	visit(ASTFunNode node, int nchildren, int depth)	Visit a function node
protected void	visit(ASTOpNode node, int nchildren, int depth)	Visit an operator node
protected void	visit(ASTVarNode node, int nchildren, int depth)	Visit a variable node
final void	writeExternal(ObjectOutput out)	Write a serialized version of the node to a stream.
static void	writeHooks(ObjectOutput oos, Map<Node.HookKey,Object> hooks)

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

suppressExaminingChildren, walk, walkSubEquations

Methods inherited from class java.lang.Object

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

Constructor Details

SerializableExpression

public SerializableExpression(Node node)
                       throws JepException

Construct a SerializableExpression from a given node

Parameters:

node - root node of the expression to serialize

Throws:

JepException

SerializableExpression

public SerializableExpression()

Constructor used by the serializable mechanism. Not for normal use.

Method Details

toNode

public final Node toNode(Jep j)
                  throws JepException

Convert to a node in a given context. Variable, function and operator nodes will refer to the corresponding object in the jep instance.

Parameters:

j - Jep instance specifying the context

Returns:

root node of the expression

Throws:

JepException

writeExternal

public final void writeExternal(ObjectOutput out)
                         throws IOException

Write a serialized version of the node to a stream.

Specified by:

writeExternal in interface Externalizable

Parameters:

out - the stream to write to.

Throws:

IOException

readExternal

public final void readExternal(ObjectInput ois)
                        throws IOException,
ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

visit

protected void visit(ASTFunNode node,
 int nchildren,
 int depth)

Description copied from class: PostfixTreeWalker

Visit a function node

Specified by:

visit in class PostfixTreeWalker

Parameters:

node - the current node being visited

nchildren - number of children of the node

depth - depth of tree, root node is depth 1.

visit

protected void visit(ASTOpNode node,
 int nchildren,
 int depth)

Description copied from class: PostfixTreeWalker

Visit an operator node

Specified by:

visit in class PostfixTreeWalker

Parameters:

node - the current node being visited

nchildren - number of children of the node

depth - depth of tree, root node is depth 1.

visit

protected void visit(ASTVarNode node,
 int nchildren,
 int depth)

Description copied from class: PostfixTreeWalker

Visit a variable node

Specified by:

visit in class PostfixTreeWalker

Parameters:

node - the current node being visited

nchildren - number of children of the node

depth - depth of tree, root node is depth 1.

visit

protected void visit(ASTConstant node,
 int nchildren,
 int depth)

Description copied from class: PostfixTreeWalker

Visit a constant node

Specified by:

visit in class PostfixTreeWalker

Parameters:

node - the current node being visited

nchildren - number of children of the node

depth - depth of tree, root node is depth 1.

iterator

public Iterator<SerializableExpression.Element> iterator()

Returns an iterator for the reverse polish representation of the expression. This iterator is unmodifiable.

writeHooks

public static void writeHooks(ObjectOutput oos,
 Map<Node.HookKey,Object> hooks)
                       throws IOException

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object