nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/package-info.java
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/*
Copyright 2009-2013 Attila Szegedi
Licensed under both the Apache License, Version 2.0 (the "Apache License")
and the BSD License (the "BSD License"), with licensee being free to
choose either of the two at their discretion.
You may not use this file except in compliance with either the Apache
License or the BSD License.
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following notice applies to you:
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/**
* <p>
* Dynalink is a library for dynamic linking high-level operations on objects
* such as "read a property", "write a property", "invoke a function" and so on,
* expressed as {@link java.lang.invoke.CallSite call sites}. As such, it is
* closely related to, and relies on, the {@link java.lang.invoke} package.
* </p><p>
* While {@link java.lang.invoke} provides a JVM-level foundation for
* application-specific dynamic linking of methods, it does not provide a way to
* express higher level operations on objects, nor methods that implement them.
* These operations are the usual regimen of operations in object-oriented
* environments: property access, access of elements of collections, invocation
* of constructors, invocation of named methods (potentially with multiple
* dispatch, e.g. link- and run-time equivalents of Java overloaded method
* resolution). These are all functions that are normally desired in a language
* on the JVM. When a JVM language is statically typed and its type system
* matches that of the JVM, it can accomplish this with use of the usual
* invocation bytecodes ({@code INVOKEVIRTUAL} etc.) as well as field access
* bytecodes ({@code GETFIELD}, {@code PUTFIELD}). However, if the language is
* dynamic (hence, types of some expressions are not known at the time the
* program is compiled to bytecode), or its type system doesn't match closely
* that of the JVM, then it should use {@code invokedynamic} call sites and let
* Dynalink link those.
* </p><p>
* Dynalink lets programs have their operations on objects of unknown static
* types linked dynamically at run time. It also lets a language expose a linker
* for its own object model. Finally, it provides a default linker for ordinary
* Java objects. Two languages both exporting their linkers in the same JVM will
* even be able to cross-link their operations with each other if an object
* belonging to one language is passed to code from the other language.
* </p>
* <p>
* Languages that use Dynalink will create and configure a
* {@link jdk.internal.dynalink.DynamicLinkerFactory} and use it to create a
* {@link jdk.internal.dynalink.DynamicLinker}.
* The thus created dynamic linker will have to be used to link any
* {@link jdk.internal.dynalink.RelinkableCallSite}s they create, most often from a
* {@link java.lang.invoke} bootstrap method.
* </p>
* <p>
* Languages that wish to define and use their own linkers will also need to
* use the {@link jdk.internal.dynalink.linker} package.
* </p>
* @since 1.9
*/
@jdk.Exported
package jdk.internal.dynalink;