Notes on modifying the fundamental classes in E-Cell 4

In E-Cell 3 the fundamental class structure is the following:

  PropertiedClass <----- Entity <------ Variable
                     |              |
                     |              |-- Process
                     |              |
                     |              |-- System
                     |
                     |-- Stepper

For E-Cell 4 that structure will be changed. First, the Entity class will be depreciated, and Variable, Process and System (as well as Stepper) will all derive directly from Entity. Next, System will be renamed to Entity, which will hold Variable objects.

Variable object will be modified so that it is no longer a PropertiedClass, but is instead just a lightweight wrapper around an ID (which acts like a pointer to a PropertySlot).

The resulting class structure will be the following:

  PropertiedClass <----- Entity (was System)
                     |          
                     |-- Process
                     |
                     |-- Stepper

  Entity <>--- Variable