How APLX Behaves in a Standalone Application

Restrictions of the Runtime Interpreter

The APL interpreter which is packaged together with your workspace to form the standalone application is an almost complete implementation of APLX, but without the capability of running in desk-calculator mode and without the APL development environment (debugger, function editor, etc). Thus, your workspace must include a latent expression which takes over when the application starts up. If your APL code ever tries to return to desk calculator mode (either because the latent expression terminates normally, or if an untrapped APL error occurs or breakpoint is hit), then the APL session will end. If it terminates because of an error, the error message will be displayed in a message box.

Other differences are:

• The APL development windows are not available. These include the Debug, Watch, Display, Workspace Explorer, and Control Browser windows.
• Edit Windows can be invoked using ⎕EDIT, but can only be used to edit variables, not functions.
• )SAVE )IN and )OUT are not implemented.

The Session window

The APLX Session window is available in standalone applications, but it behaves in a special way. On start-up, the Session window does not appear, and the normal APLX sign-on message is not displayed. It will remain hidden unless your packaged application performs ordinary APL output to the Session window, or requests input using ⎕ or ⍞ input. It behaves in a similar way to the Session window in the full version of APLX, but with a simplified set of menus.

This provides flexibility for various requirements, for example:

• A simple traditional APL application which uses the Session window for output and ⎕ for input can be packaged into a Standalone application and will work as it does when running under the full version of APLX.
• An APLX server or file-processing application can use the Session window as a 'log' window, outputting messages to it to indicate progress, or can run in the background without any windows.
• A full windowing application, built using System Classes, can run without the Session window ever appearing.

The APLX font

Use of the APLX font in your applications is optional. Applications which use System Classes for user-interface programming probably will not need the APL font, but if you use the Session window for output we recommend that you do install the APLX font on machines running the application.