| /******************************************************************************* |
| * Copyright (c) 2009 - 2010 Cloudsmith Inc. and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Cloudsmith Inc. - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.equinox.p2.metadata.expression; |
| |
| /** |
| * The evaluation context. Contexts can be nested and new contexts are pushed for each closure |
| * during an evaluation of an expression. |
| * @since 2.0 |
| */ |
| public interface IEvaluationContext { |
| /** |
| * Retrieve the value of the given <code>variable</code> from this context |
| * @param variable The variable who's value should be retrieved |
| * @return The current value for the variable |
| */ |
| Object getValue(IExpression variable); |
| |
| /** |
| * Set the current value for the given <code>variable</code> to <code>value</code> |
| * @param variable The variable who's value should be set |
| * @param value The new value for the variable. |
| */ |
| void setValue(IExpression variable, Object value); |
| |
| /** |
| * Returns the value of the parameter at the given <code>position</code> |
| * @param position The zero based position for the parameter |
| * @return The parameter value |
| */ |
| Object getParameter(int position); |
| } |
