com.singularsys.jep
Class NodeFactory

java.lang.Object
  com.singularsys.jep.NodeFactory

All Implemented Interfaces:

JepComponent, java.io.Serializable

Direct Known Subclasses:

LineNumberingNodeFactory

public class NodeFactory
extends java.lang.Object
implements JepComponent

This class is used to create nodes of specified types. It can be sub-classed to change the nature of how nodes are constructed. Generally there are two methods for creating nodes, methods which take an existing node and methods which take the components.

Author:

Rich Morris Created on 16-Nov-2003

See Also:

Serialized Form

Field Summary

protected Evaluator	ev
protected Jep	j
protected VariableTable	vt

Constructor Summary

NodeFactory()

Method Summary

ASTConstant	buildConstantNode(ASTConstant node) Create an ASTConstant with same value as argument
ASTConstant	buildConstantNode(java.lang.Object value) Creates an ASTConstant node with specified value.
ASTConstant	buildConstantNode(Operator op, Node child1) Creates a ASTConstant whose value of applying a unary operator to its arguments.
ASTConstant	buildConstantNode(Operator op, Node[] children) Creates a ASTConstant whose value of applying the operator to its arguments.
ASTConstant	buildConstantNode(Operator op, Node child1, Node child2) Creates a ASTConstant whose value of applying binary operator to its arguments.
ASTConstant	buildConstantNode(PostfixMathCommandI pfmc, Node[] children) Creates a constant node whose result is the given function applied to the children.
ASTFunNode	buildFunctionNode(ASTFunNode node, Node[] arguments) Builds a function with n arguments and same fun as specified in arguments.
ASTFunNode	buildFunctionNode(java.lang.String name, PostfixMathCommandI pfmc, Node[] arguments) Builds a function with n arguments This method should be sub-classed
ASTOpNode	buildOperatorNode(Operator op, Node child) creates a unary function.
ASTOpNode	buildOperatorNode(Operator op, Node[] arguments) Builds a operator node with n arguments This method should be sub-classed
ASTOpNode	buildOperatorNode(Operator op, Node lhs, Node rhs) creates a binary function.
ASTOpNode	buildUnfinishedOperatorNode(Operator op) An unfinished node.
ASTVarNode	buildVariableNode(ASTVarNode node) creates a new ASTVarNode with the same name as argument.
ASTVarNode	buildVariableNode(java.lang.String name) Build a variable node when just the name is known.
ASTVarNode	buildVariableNode(Variable var) creates a new ASTVarNode with a given variable.
ASTVarNode	buildVariableNodeCheckUndeclared(java.lang.String name) Build a variable node checking for the undeclared status.
void	copyChildren(Node node, Node[] children) Sets the children of node to be those specified in array.
JepComponent	getLightWeightInstance() Gets a light-weight instance suitable for using in multiple threads.
void	init(Jep jep) Initialize the component.

Methods inherited from class java.lang.Object

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

Field Detail

ev

protected transient Evaluator ev

vt

protected transient VariableTable vt

j

protected transient Jep j

Constructor Detail

NodeFactory

public NodeFactory()

Method Detail

init

public void init(Jep jep)

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:

jep - the current Jep instance

copyChildren

public void copyChildren(Node node,
                         Node[] children)

Sets the children of node to be those specified in array.

Parameters:

node - the node whose children will be set.

children - an array of nodes which will be the children of the node.

buildConstantNode

public ASTConstant buildConstantNode(java.lang.Object value)
                              throws ParseException

Creates an ASTConstant node with specified value. This method should be overwritten by subclasses.

Throws:

ParseException

buildConstantNode

public ASTConstant buildConstantNode(ASTConstant node)
                              throws ParseException

Create an ASTConstant with same value as argument. *

Throws:

ParseException

buildConstantNode

public ASTConstant buildConstantNode(PostfixMathCommandI pfmc,
                                     Node[] children)
                              throws ParseException

Creates a constant node whose result is the given function applied to the children.

Parameters:

pfmc - the function to apply

children - the arguments to the function, each argument should be a constant node.

Returns:

a new constant node

Throws:

ParseException

buildConstantNode

public ASTConstant buildConstantNode(Operator op,
                                     Node[] children)
                              throws ParseException

Creates a ASTConstant whose value of applying the operator to its arguments.

Throws:

ParseException

buildConstantNode

public ASTConstant buildConstantNode(Operator op,
                                     Node child1,
                                     Node child2)
                              throws ParseException

Creates a ASTConstant whose value of applying binary operator to its arguments.

Throws:

ParseException

buildConstantNode

public ASTConstant buildConstantNode(Operator op,
                                     Node child1)
                              throws ParseException

Creates a ASTConstant whose value of applying a unary operator to its arguments.

Throws:

ParseException

buildVariableNode

public ASTVarNode buildVariableNode(ASTVarNode node)
                             throws ParseException

creates a new ASTVarNode with the same name as argument.

Throws:

ParseException

buildVariableNode

public ASTVarNode buildVariableNode(Variable var)
                             throws ParseException

creates a new ASTVarNode with a given variable. This method should be sub-classed

Throws:

ParseException

buildVariableNode

public ASTVarNode buildVariableNode(java.lang.String name)
                             throws ParseException

Build a variable node when just the name is known.

Parameters:

name - the name of the variable

Returns:

the node created

Throws:

ParseException

buildVariableNodeCheckUndeclared

public ASTVarNode buildVariableNodeCheckUndeclared(java.lang.String name)
                                            throws ParseException

Build a variable node checking for the undeclared status.

Parameters:

name - name of the variable

Returns:

a new node

Throws:

ParseException - if undeclared variables are not allowed and the variable does not exist

buildOperatorNode

public ASTOpNode buildOperatorNode(Operator op,
                                   Node[] arguments)
                            throws ParseException

Builds a operator node with n arguments This method should be sub-classed

Parameters:

op - the operator to use

arguments - the arguments to the function.

Returns:

top Node of expression

Throws:

ParseException

buildFunctionNode

public ASTFunNode buildFunctionNode(java.lang.String name,
                                    PostfixMathCommandI pfmc,
                                    Node[] arguments)
                             throws ParseException

Builds a function with n arguments This method should be sub-classed

Parameters:

name - of function.

pfmc - PostfixMathCommand for function.

arguments - the arguments to the function.

Returns:

top Node of expression

Throws:

ParseException

buildUnfinishedOperatorNode

public ASTOpNode buildUnfinishedOperatorNode(Operator op)

An unfinished node. Caller has responsibility for filling in the children.

buildOperatorNode

public ASTOpNode buildOperatorNode(Operator op,
                                   Node child)
                            throws ParseException

creates a unary function.

Throws:

ParseException

buildOperatorNode

public ASTOpNode buildOperatorNode(Operator op,
                                   Node lhs,
                                   Node rhs)
                            throws ParseException

creates a binary function.

Throws:

ParseException

buildFunctionNode

public ASTFunNode buildFunctionNode(ASTFunNode node,
                                    Node[] arguments)
                             throws ParseException

Builds a function with n arguments and same fun as specified in arguments.

Parameters:

node - the properties (name and pfmc) of this node will be copied.

arguments - the arguments to the function.

Returns:

top Node of expression

Throws:

ParseException

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:

new NodeFactory()