Universes Libraries System

Introduction

The notion of 'universe' is not the same since the advent of 'ecf' files. The understanding of those terms diverged from the one appeared with xace files.

Universe

A universe is set of classes in an ECF library or an 'assembly'. In an ECF or an assembly, each class has a unique name.

System

A system is defined with an ECF. A system assembles clusters and other ECF libraries.

A system is thus a universe that recursively references other universes (libraries or assemblies).

Group

A 'group' is a physical location where a class resides.

This is either a cluster (directory) or a .NET assembly.

Classes and Universes

In a universe, classes come from

• a group that is locally defined in this universe
• another library (embedded universe). In that case, the classes are 'imported' from the embedded universe.

A class (ET_CLASS) corresponds to a physical class (a file with its textual representation).

For incremental compilation purpose, there is a supplementary indirection. In a universe, each class name is associated with a master class (ET_MASTER_CLASS). The master class is resolved at compile time to a class that is declared locally in the universe, or imported from another universe (or library).

{ET_MASTER_CLASS}.actual_class gives access to the 'resolved' class.

Dependencies between universes are recursive. If you want to browse things, you have to use the *_do_recurse features from ET_SYSTEM to browse an entire universe.

For example, calling an action for every class in a system is done like this:

my_system.classes_do_recursive (agent action)

To feed a list with all classes in a system :

my_list: DS_LINKED_LIST[ET_CLASS]
...
my_system.classes_do_recursive (agent my_list.put_last)

Note

From my experience at this time (PGC, November 19, 2012) I can say that you have to use a system straight from a system parser.

The original eDoc code did the following:

1. Parse a system/library
2. Append the clusters to a list of clusters
3. Create a system from scratch, setting the list of clusters obtained in (2)

Unfortunately, in that case, the *_do_recursive functions do not work on this newly created universe.