Package com.singularsys.jep

Interface Evaluator

All Superinterfaces:

JepComponent, Serializable

All Known Implementing Classes:

FastEvaluator, FastEvaluator3_4, FastEvaluator3_5, MonitoringEvaluator, PostfixEvaluator, RealEvaluator, RpEvaluator, StackCheckingFastEvaluator, StandardEvaluator, StreamEvaluator, StructuredEvaluator, ThreadSafeEvaluator, UncheckedEvaluator, XEvaluator, XMonitoringEvaluator

public interface Evaluator
extends JepComponent

Defines a method which can be used to evaluate a part of a node-tree. It is passed to classes that use CallbackEvaluatorI which need greater control over how they are evaluated.

Author:

Rich Morris Created on 22-Apr-2005

See Also:

• CallbackEvaluationI

Method Summary

Modifier and Type	Method	Description
default Object	eval(NodeFactory nf, String name, PostfixMathCommandI pfmc, Node... children)	Evaluates a function with the given children.
Object	eval(Node node)	Evaluates a sub expression.
Object	evaluate(Node node)	Main entry point, evaluates a node and returns and object with the value of the node.

Methods inherited from interface com.singularsys.jep.JepComponent

getLightWeightInstance, init

Method Details

evaluate

Object evaluate(Node node)
         throws EvaluationException

Main entry point, evaluates a node and returns and object with the value of the node.

Parameters:

node - node to evaluate

Returns:

value after evaluation

Throws:

EvaluationException - if errors occur during evaluation;

eval

Object eval(Node node)
     throws EvaluationException

Evaluates a sub expression. This method can be called by PostfixMathCommands which implement CallbackEvaluationI

Parameters:

node - node to evaluate

Returns:

The value after evaluating the sub expression.

Throws:

EvaluationException - if errors occur during evaluation;

eval

default Object eval(NodeFactory nf,
 String name,
 PostfixMathCommandI pfmc,
 Node... children)
             throws EvaluationException

Evaluates a function with the given children. If the function is one of UnaryFunction, BinaryFunction, NaryFunction, NaryBinaryFunction, or NullaryFunction then the appropriate eval method is called. Otherwise a temporary node is created with the given function and children and evaluated this this evaluator. This allows functions with special evaluations behaviour like CallbackEvaluationI to be evaluated correctly.

Parameters:

nf - NodeFactory to use to create a temporary node

name - name of the function

pfmc - the function to evaluate

children - the children of the node to evaluate

Returns:

The value after evaluating the function.

Throws:

EvaluationException - if the pfmc is null or the number of children is not valid for the function.