Re: Need advice: Enumerate or not

[Jim Rogers <jimmaureenrogers@worldnet.att.net>]

Both approaches will work.

The use of enumerated types is clearly more of an Ada 83 design
pattern. Its limitation is that you must update the source code
for the Update procedure when new options are permitted.

The use of dispatching is clearly more of an Ada 95 design
pattern. Its main advantage is that you never need to change
the Update procedure taking a parameter of type
"access Gtk_Frame_Record'Class". All you need to do is override the
Update procedure for the new child type of Gtk_Frame_Record.

The Ada 95 approach is perhaps harder to read, because all the
decisions are performed by dispatching and not by explicit
branching in your code. On the other hand, the dispatching
approach reduces maintenance cost and explicit complexity.

Jim Rogers