The Joe Language

Joe is a Java-like dynamic scripting language:

• Meant for adding scriptability to Java applications and libraries.
• Designed to be comfortable for Java developers.
• Designed to be easy to extend in Java.

But equally, Joe is designed to be insulated from the larger Java world. Adding a Joe interpreter should not, on its own, add security issues to an application.

A vanilla Joe interpreter:

• Has no access to the host operating system.
  • Unless the client implements a Java binding for Joe that provides such access.
• Has no access to the Java standard library.
  • Except insofar as the Joe standard library depends on it.

The client is free to add bindings in Java that do both, as described in the Extending Joe section, and as the joe run and joe repl do by adding the joe.console package.

Joe has its origin in the JLox language from Robert Nystrom's outstanding book and website, Crafting Interpreters, but is by no means identical to JLox. (If you should happen to find Joe useful, please buy a copy of Nystrom's book.)

The following sections describe the language in more detail.