Author's_notes modified by Hugh Greene

Hugh Greene — Fri, 20 Jan 2023 12:12:45 -0000

I'll be brief, and someone can format this all nice-like later.

While extending ENIGMA by adding a new API is simple and requires
minimal rewriting, extending it by porting to a new language (other than
C++) involves a total rewrite of all systems, including functions
defined by Universal_System/, which is
responsible for sensitive and important key systems, such as instance
management. This page is a collection of notes from developers who have
implemented these systems; may they help you in porting to new
languages.

Instance Management

Storage

To implement GM's random-access routines on objects by index, by id, and
by heritage, it is wise to store a data structure of some kind for each
of those. In C++, a list is kept for each object index, and a map is
kept for id-based access. Children of an object are added to both the
parent's list and the child's list.

Destruction

In compiled languages, instance_destroy() is a dangerous mechanism.
Since it is the current instance that is being destroyed, it would be
folly to free concerned memory immediately upon the call to the
function. Instead, iterators are removed during the call, but are kept
valid, and maintained upon later destroys. Instances are "Garbage
Collected" at the end of the event, and the iterators finally removed.

Instantiation

In the C version, upon instantiation, each object adds its own iterators
and keeps a reference to them for when it is destroyed. The actual
destructor is designed to remove them.

Recent changes to Author's_notes

Author's_notes modified by Hugh Greene

Instance Management

Storage

Destruction

Instantiation