/*
 * @(#)ScriptEngineFactory.java	1.3 05/11/17 14:24:14
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTAIL. Use is subject to license terms.
 */

package javax.script;

import java.util.List;

/**
 * <code>ScriptEngineFactory</code> is used to describe and instantiate
 * <code>ScriptEngines</code>.
 * <br><br>
 * Each class implementing <code>ScriptEngine</code> has a corresponding factory
 * that exposes metadata describing the engine class.
 * <br><br>The <code>ScriptEngineManager</code>
 * uses the service provider mechanism described in the <i>Jar File Specification</i> to obtain
 * instances of all <code>ScriptEngineFactories</code> available in
 * the current ClassLoader.
 *
 * @since 1.6
 */
public interface ScriptEngineFactory {
    /**
     * Returns the full  name of the <code>ScriptEngine</code>.  For
     * instance an implementation based on the Mozilla Rhino Javascript engine
     * might return <i>Rhino Mozilla Javascript Engine</i>.
     * @return The name of the engine implementation.
     */
    public String getEngineName();
    
    /**
     * Returns the version of the <code>ScriptEngine</code>.
     * @return The <code>ScriptEngine</code> implementation version.
     */
    public String getEngineVersion();
    
    
    /**
     * Returns an immutable list of filename extensions, which generally identify scripts
     * written in the language supported by this <code>ScriptEngine</code>.
     * The array is used by the <code>ScriptEngineManager</code> to implement its
     * <code>getEngineByExtension</code> method.
     * @return The list of extensions.
     */
    public List<String> getExtensions();
    
    
    /**
     * Returns an immutable list of mimetypes, associated with scripts that
     * can be executed by the engine.  The list is used by the
     * <code>ScriptEngineManager</code> class to implement its
     * <code>getEngineByMimetype</code> method.
     * @return The list of mime types.
     */
    public List<String> getMimeTypes();
    
    /**
     * Returns an immutable list of  short names for the <code>ScriptEngine</code>, which may be used to
     * identify the <code>ScriptEngine</code> by the <code>ScriptEngineManager</code>.
     * For instance, an implementation based on the Mozilla Rhino Javascript engine might
     * return list containing {"javascript", "rhino"}.
     */
    public List<String> getNames();
    
    /**
     * Returns the name of the scripting langauge supported by this
     * <code>ScriptEngine</code>.
     * @return The name of the supported language.
     */
    public String getLanguageName();
    
    /**
     * Returns the version of the scripting language supported by this
     * <code>ScriptEngine</code>.
     * @return The version of the supported language.
     */
    public String getLanguageVersion();
    
    /**
     * Returns the value of an attribute whose meaning may be implementation-specific.
     * Keys for which the value is defined in all implementations are:
     * <ul>
     * <li>ScriptEngine.ENGINE</li>
     * <li>ScriptEngine.ENGINE_VERSION</li>
     * <li>ScriptEngine.NAME</li>
     * <li>ScriptEngine.LANGUAGE</li>
     * <li>ScriptEngine.LANGUAGE_VERSION</li>
     * </ul>
     * <p>
     * The values for these keys are the Strings returned by <code>getEngineName</code>,
     * <code>getEngineVersion</code>, <code>getName</code>, <code>getLanguageName</code> and
     * <code>getLanguageVersion</code> respectively.<br><br>
     * A reserved key, <code><b>THREADING</b></code>, whose value describes the behavior of the engine
     * with respect to concurrent execution of scripts and maintenance of state is also defined.
     * These values for the <code><b>THREADING</b></code> key are:<br><br>
     * <ul>
     * <p><code>null</code> - The engine implementation is not thread safe, and cannot