Make initial REPL integration. You can try it in Rust Console tool window. The current implementation includes syntax highlighting, basic completion and command history. Under the hood, it uses evcxr util, so the integration requires this util to be installed. If you don’t have it yet, the plugin suggests installing it in one click after the first usage of Rust Console tool window. For now, it’s disabled by default. To turn it on, you need to enable org.rust.ide.repl.tool.window option in Experimental Features dialog (by @dima74)