1 /*
2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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10 *
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15 * accompanied this code).
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25
26 /**
27 * Provides the implementation of Nashorn script engine and
28 * the runtime environment for programs written in ECMAScript 5.1.
29 * <p>
30 * Nashorn is a runtime environment for programs written in ECMAScript 5.1.
31 * </p>
32 *
33 * <h1>Usage</h1>
34 *
35 * The recommended way to use Nashorn is through the
36 * <a href="http://jcp.org/en/jsr/detail?id=223" target="_top">JSR-223
37 * "Scripting for the Java Platform"</a> APIs found in the
38 * {@link javax.script} package. Usually, you'll obtain a
39 * {@link javax.script.ScriptEngine} instance for Nashorn using:
40 * <pre>
41 import javax.script.*;
42 ...
43 ScriptEngine nashornEngine = new ScriptEngineManager().getEngineByName("nashorn");
44 </pre>
45 *
46 * and then use it just as you would any other JSR-223 script engine. See
47 * <a href="jdk/nashorn/api/scripting/package-summary.html">
48 * {@code jdk.nashorn.api.scripting}</a> package for details.
49 * <h1>Compatibility</h1>
50 * Nashorn is 100% compliant with the
51 * <a href="http://www.ecma-international.org/publications/standards/Ecma-262.htm"
52 * target="_top">ECMA-262 Standard, Edition 5.1</a>.
53 * It requires a Java Virtual Machine that implements the
54 * <a href="http://jcp.org/en/jsr/detail?id=292" target="_top">
55 * JSR-292 "Supporting Dynamically Typed Languages on the Java Platform"</a>
56 * specification (often referred to as "invokedynamic"), as well as
57 * the already mentioned JSR-223.
58 *
59 * <h1>Interoperability with the Java platform</h1>
60 *
61 * In addition to being a 100% ECMAScript 5.1 runtime, Nashorn provides features
62 * for interoperability of the ECMAScript programs with the Java platform.
63 * In general, any Java object put into the script engine's context will be
64 * visible from the script. In terms of the standard, such Java objects are not
65 * considered "native objects", but rather "host objects", as defined in
66 * section 4.3.8. This distinction allows certain semantical differences
67 * in handling them compared to native objects. For most purposes, Java objects
68 * behave just as native objects do: you can invoke their methods, get and set
69 * their properties. In most cases, though, you can't add arbitrary properties
70 * to them, nor can you remove existing properties.
71 *
72 * <h2>Java collection handling</h2>
73 *
74 * Native Java arrays and {@link java.util.List}s support indexed access to
75 * their elements through the property accessors, and {@link java.util.Map}s
76 * support both property and element access through both dot and square-bracket
77 * property accessors, with the difference being that dot operator gives
78 * precedence to object properties (its fields and properties defined as
79 * {@code getXxx} and {@code setXxx} methods) while the square bracket
80 * operator gives precedence to map elements. Native Java arrays expose
81 * the {@code length} property.
82 *
83 * <h2>ECMAScript primitive types</h2>
84 *
85 * ECMAScript primitive types for number, string, and boolean are represented
86 * with {@link java.lang.Number}, {@link java.lang.CharSequence}, and
87 * {@link java.lang.Boolean} objects. While the most often used number type
88 * is {@link java.lang.Double} and the most often used string type is
89 * {@link java.lang.String}, don't rely on it as various internal optimizations
90 * cause other subclasses of {@code Number} and internal implementations of
91 * {@code CharSequence} to be used.
92 *
93 * <h2>Type conversions</h2>
94 *
95 * When a method on a Java object is invoked, the arguments are converted to
96 * the formal parameter types of the Java method using all allowed ECMAScript
97 * conversions. This can be surprising, as in general, conversions from string
98 * to number will succeed according to Standard's section 9.3 "ToNumber"
99 * and so on; string to boolean, number to boolean, Object to number,
100 * Object to string all work. Note that if the Java method's declared parameter
101 * type is {@code java.lang.Object}, Nashorn objects are passed without any
102 * conversion whatsoever; specifically if the JavaScript value being passed
103 * is of primitive string type, you can only rely on it being a
104 * {@code java.lang.CharSequence}, and if the value is a number, you can only
105 * rely on it being a {@code java.lang.Number}. If the Java method declared
106 * parameter type is more specific (e.g. {@code java.lang.String} or
107 * {@code java.lang.Double}), then Nashorn will of course ensure
108 * the required type is passed.
109 *
110 * <h2>SAM types</h2>
111 *
112 * As a special extension when invoking Java methods, ECMAScript function
113 * objects can be passed in place of an argument whose Java type is so-called
114 * "single abstract method" or "SAM" type. While this name usually covers
115 * single-method interfaces, Nashorn is a bit more versatile, and it
116 * recognizes a type as a SAM type if all its abstract methods are
117 * overloads of the same name, and it is either an interface, or it is an
118 * abstract class with a no-arg constructor. The type itself must be public,
119 * while the constructor and the methods can be either public or protected.
120 * If there are multiple abstract overloads of the same name, the single
121 * function will serve as the shared implementation for all of them,
122 * <em>and additionally it will also override any non-abstract methods of
123 * the same name</em>. This is done to be consistent with the fact that
124 * ECMAScript does not have the concept of overloaded methods.
125 *
126 * <h2>The {@code Java} object</h2>
127 *
128 * Nashorn exposes a non-standard global object named {@code Java} that is
129 * the primary API entry point into Java platform-specific functionality.
130 * You can use it to create instances of Java classes, convert from Java arrays
131 * to native arrays and back, and so on.
132 *
133 * <h2>Other non-standard built-in objects</h2>
134 *
135 * In addition to {@code Java}, Nashorn also exposes some other
136 * non-standard built-in objects:
137 * {@code JSAdapter}, {@code JavaImporter}, {@code Packages}
138 *
139 * @provides javax.script.ScriptEngineFactory
140 * @moduleGraph
141 * @since 9
142 */
143 module jdk.scripting.nashorn {
144 requires java.logging;
145 requires transitive java.scripting;
146 requires jdk.dynalink;
147
148 exports jdk.nashorn.api.scripting;
149 exports jdk.nashorn.api.tree;
150
151 exports jdk.nashorn.internal.runtime to
152 jdk.scripting.nashorn.shell;
153 exports jdk.nashorn.internal.objects to
154 jdk.scripting.nashorn.shell;
155 exports jdk.nashorn.tools to
156 jdk.scripting.nashorn.shell;
157
158 provides javax.script.ScriptEngineFactory
159 with jdk.nashorn.api.scripting.NashornScriptEngineFactory;
160
161 provides jdk.dynalink.linker.GuardingDynamicLinkerExporter
162 with jdk.nashorn.api.linker.NashornLinkerExporter;
163 }