Package com.singularsys.extensions.structure

Class StructureNode

java.lang.Object

com.singularsys.jep.parser.SimpleNode

com.singularsys.extensions.structure.StructureNode

All Implemented Interfaces:

Node

Direct Known Subclasses:

ControlNode, IfNode, LoopNode, SequenceNode

public abstract class StructureNode
extends SimpleNode

Base class for all structure nodes, defines an eval method.

Author:

Richard Morris

Nested Class Summary

Nested classes/interfaces inherited from interface com.singularsys.jep.parser.Node

Node.HookKey

Field Summary

Fields inherited from class com.singularsys.jep.parser.SimpleNode

children, id, keys, parent, vals

Constructor Summary

Constructors

Constructor	Description
StructureNode(int i)

Method Summary

Modifier and Type	Method	Description
abstract Object	eval(Evaluator ev)	Evaluate the node
String	getName()	Return the name associated with the node (if any).
Operator	getOperator()	Return the operator associated with a Node (if any)
PostfixMathCommandI	getPFMC()	Return the pfmc of a node (if any)
Object	getValue()	Return the value associated with the node (if any).
Variable	getVar()	Return the variable associated with a Node (if any)
protected static boolean	testCondition(Object val)	Convert a value to boolean, for use in condition tests

Methods inherited from class com.singularsys.jep.parser.SimpleNode

childIterator, children, childrenAccept, dump, getChildren, getHook, getId, hookKeys, jjtAccept, jjtAddChild, jjtClose, jjtGetChild, jjtGetNumChildren, jjtGetParent, jjtOpen, jjtSetParent, removeHook, setHook, toString

Methods inherited from class java.lang.Object

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

Constructor Details

StructureNode

public StructureNode(int i)

Method Details

eval

public abstract Object eval(Evaluator ev)
                     throws EvaluationException

Evaluate the node

Parameters:

ev - The evaluator the Evaluator.eval(com.singularsys.jep.parser.Node) can be used to evaluate children.

Returns:

result of evaluation

Throws:

EvaluationException - if evaluation cannot be performed

getName

public String getName()

Description copied from interface: Node

Return the name associated with the node (if any).

Returns:

the name if an ASTVarNode, ASTFunNode, ASTOpNode, null otherwise

getOperator

public Operator getOperator()

Description copied from interface: Node

Return the operator associated with a Node (if any)

Returns:

The Operator for ASTOpNodes, null otherwise

getPFMC

public PostfixMathCommandI getPFMC()

Description copied from interface: Node

Return the pfmc of a node (if any)

Returns:

the PostfixMathCommand for ASTFunNode and ASTOpNode, null otherwise

getValue

public Object getValue()

Description copied from interface: Node

Return the value associated with the node (if any).

Returns:

the value if an ASTConstant, ASTVarNode, null otherwise

getVar

public Variable getVar()

Description copied from interface: Node

Return the variable associated with a Node (if any)

Returns:

The Variable for ASTVarNodes, null otherwise

testCondition

protected static boolean testCondition(Object val)
                                throws EvaluationException

Convert a value to boolean, for use in condition tests

Parameters:

val - value to test, a Number or Boolean

Returns:

val converted to a boolean

Throws:

EvaluationException - if val cannot be converted to a boolean