This chapter describes several important classes and structures that provide the main way of specifying all of the part, instrument, and notational information that is passed to FOMUS for processing. Each section gives a description of a class or structure, its constructor, and a list of its accessor functions. How these are actually used depends on the interface that the user chooses to use (See Usage for more information).

All constructor functions have a corresponding copy function that take exactly the same keyword arguments plus one extra argument (the object to be copied). Any keyword/argument pairs supplied when a copy function is called indicate new replacement values. Objects may therefore be used as templates for creating new objects that differ only in one or two slot values.

The actual class hierarchy isn't given here since it shouldn't be of any concern for most users. It is reflected somewhat in the prefixes that appear in the accessor function names.