The SOM run-time library

In addition to the SOM Compiler, SOM includes a run-time library. This library provides, among other things, a set of classes, methods, and procedures used to create object and invoke methods on them. The library allows any programming language to use SOM classes (classes developed using SOM) if that language can:

• Call external procedures,

• Store a pointer to a procedure and subsequently invoke that procedure, and

• Map IDL types onto the programming language's native types.

Thus, the user of a SOM class and the implementer of a SOM class needn't use the same programming language, and neither is required to use an object-oriented language. The independence of client language and implementation language also extends to subclassing: a SOM class can be derived from other SOM classes, and the subclass may or may not be implemented in the same language as the parent class(es). Moreover, SOM's run-time environment allows applications to access information about classes dynamically (at run time).