Introduction to gmSL

The name gmSL stands for Great Migrations Scripting language. It is high-level programming language that is compiled and executed by gmBasic rather than compiled by the computer's processor as other programming languages (such as C and C++) are. Code written in gmSL can be embedded within gmPL scripts or can be in stand alone in source files with the extension gmSL. The gmSL language fully supports gmPL equivalents of the main line gmPL statements and can be used as a substitute for gmPL in most cases. gmSL is a procedural language and does not reproduce the gmPL declaration statements. The goal of gmSL is to enhance gmPL not to replace it.

First and foremost, gmSL is a compiled language. Its statements are converted into byte codes and those byte code are then either executed immediately or are saved to be executed at a later time. The byte codes themselves are 100% compatible with those used by gmBasic to compile the various source lanuages that it processes. The engine used to execute the byte codes is the same as the one used to evaluate constant expressions in source codes.

There are many contexts in which gmSL can be used to enhance an gmPL script. the following topics describe these contexts and are intended to serve as an introdution to the capabilities of gmSL. The remainder of this manual describe the details of the language.

Embedding gmSL Expressions in gmPL Statements

The notation (%= ... %) is used.

Embedding gmSL Statements in gmPL Scripts

The notation ... is used.

Writing Stand Alone gmSL Scripts

Stand alone files with the extension gmSL can be executed directly from the command line.

Embedding gmSL Methods in the Language File

Many of the operations performed by gmBasic can be specified using gmSL defined methods that are precompiled in the language file.

Embedding gmSL Methods in a Global Settings File

Operations to be performed by multiple translation scripts can be specified using gmSL defined methods that are precompiled in a global settings.

Overriding gmSL language Methods in gmPL Scripts

Any precompiled gmSL method in the language file can be overridden in a translation script.

Using gmSL to Author Control Properties

Special methods can be entered into library description files that author control properties.