org.ogf.graap.wsag.interpreter.expr
Class AbstractExpression

java.lang.Object
  org.ogf.graap.wsag.interpreter.expr.AbstractExpression

All Implemented Interfaces:

IExpression

Direct Known Subclasses:

AllExpression, ExactlyOneExpression, OneOrMoreExpression

public abstract class AbstractExpression
extends Object
implements IExpression

WS-Agreement allows to logically compose terms in an agreement using a simple expression language. Terms can be composed using logical AND (All), OR (OneOrMore), and XOR (ExacltyOne) operations in the agreement terms. This abstract expression implementation is the base class for the concrete implementations. It is used by the AgreementInterpreter that evaluates the validity of the agreement terms in an offer with respect to the expression language.

Author:

Oliver Waeldrich

See Also:

AgreementInterpreter

Constructor Summary

AbstractExpression(TermCompositorType term)
Creates an expression for a given term compositor.

Method Summary

TermType[]	interpret(InterpreterContext context) interprets an expression
protected abstract TermType[]	interpret(TermType[] terms, InterpreterContext context) template method that implements a specific interpretation strategy.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractExpression

public AbstractExpression(TermCompositorType term)

Creates an expression for a given term compositor.

Parameters:

term - the agreement term compositor

Method Detail

interpret

protected abstract TermType[] interpret(TermType[] terms,
                                        InterpreterContext context)
                                 throws InterpreterException

template method that implements a specific interpretation strategy. The strategy interprets a set of terms and returns a result, i.e. the selected term in an ExactlyOne statement.

Parameters:

terms - the terms to interpret

context - the interpreter context

Returns:

the strategy result, i.e. a filtered term list

Throws:

InterpreterException - indicates an error during the term interpretation

interpret

public TermType[] interpret(InterpreterContext context)
                     throws InterpreterException

interprets an expression

Specified by:

interpret in interface IExpression

Parameters:

context - the interpreter context

Returns:

the terms in the expression

Throws:

InterpreterException - indicates an error while processing the context