Re: Help: Ada and Object-Oriented Methodologies

[rlk@rational.com (Bob Kitzberger)]

[tried email, but it bounced...]

There are two versions of the Ada standard: Ada 83, which supports
object-based programming; and Ada 95 which supports object-oriented
programming directly.

For a discussion of Ada83 object-based programming, see Booch's book
(the first edition) of "Object Oriented Design with
Applications". Basically, you define a class as a private type, and
encapsulate it and all of its functions in a package, e.g.:

	-- Ada 83 object-based example
	with Color;		-- other classes referenced
	with Manufacturer;	--  "
	package Automobile is

	  type Object is private;

	  function Create( The_Color : Color.Object;
			   The_Manufacturer : Manufacturer.Object )
			   return Object;

	  procedure Destroy ( The_Auto : in out Object );

	  function The_Color( Of_Auto : in Object ) return Color.Object;
	  function The_Manufacturer( Of_Auto : in Object ) return
		Manufacturer.Object;

	  ...etc other selectors/accessors/etc...
	private
	  type Object is ...
	end Automobile;

Using this "class":

	My_Car : Automobile.Object :=
		Automobile.Create( Color.Hunter_Green,
				   Manufacturer.Jeep );
	...
	C : Color.Object := Automobile.The_Color( My_Car );


For Ada95 clases, inheritance, etc.  see the Ada 95 reference manual
(poke around in the <A HREF="http://lglwww.epfl.ch/Ada/"> Home of the
Brave Ada Programmers </A>


--
Bob Kitzberger	        +1 (916) 274-3075	        rlk@rational.com
Rational Software Corp., 10565 Brunswick Rd. #11, Grass Valley, CA 95945
  "...the solution to the problem is usually to pee on it"  -- Dave Barry