Provide an interactive tool to evaluate declarations, statements, and expressions of the Java programming language, together with an API so that other applications can leverage this functionality. Adds Read-Eval-Print Loop (REPL) functionality for Java.

The `jshell` tool accepts "snippets" of Java code, evaluating them and immediately displaying the results. Snippets include variable and method declarations without enclosing class. An expression snippet immediately shows its value. The `jshell` tool also accepts commands for displaying and controlling snippets.

The `jshell` tool is built on the JShell API, making the evaluation of snippets of Java code available any Java program.

See:
  - [`jshell` tool User's Guide](http://docs.oracle.com/javase/9/jshell/toc.htm)
  - [`jshell` tool Reference](https://docs.oracle.com/javase/9/tools/jshell.htm)
  - [JShell API Specification](http://download.java.net/java/jdk9/docs/api/jdk/jshell/package-summary.html)
  - [JShell module specification](http://download.java.net/java/jdk9/docs/api/jdk.jshell-summary.html)