HOMEWORK PROBLEM 9X_1         INTRODUCTION TO Ada   586


  PURPOSE:      To gain some experience with Ada9X. This problem
                can be worked on the gnat compiler. 


  END RESULT:   A package Shapes, compiled on an Ada9X compiler.


  PROBLEM:      Page 406, Barnes Programming in Ada, exercise 17.2.1


  TURN IN:      Printout of whatever you can capture.


  OBSERVE:      gnat naming conventions for now, require the file name
                to be the compilation unit name with .ads for specs and
                .adb for bodies.
                This is just a first example of the object oriented
                features added to Ada9X, there are more.


  METHOD:       Read Barns book, pages 398-406

                Compile with command  gcc -c gnate gnatf xxx.adb
                (There is usually no need to compile specs that have bodies)

                Link with  gnatbl -o  xxx  xxx.ali
                (having compiled non generic bodies first)

                run with   xxx

  READING:      BARNES  17.1, 17.2
                Ada9X Reference Manual  3.9

                ECLUS::CAS$DOC:ADA_RM9X_44.PS  is latest ISO draft
 





  New features in Ada9X


  Object Oriented Programming related:

    Tagged types, abstract types, type extension, class wide types,
    run time polymorphism, late binding, dispatching,
    access types for subprograms


  Program Libraries

    No longer a flat name space, child libraries, ability to "use" a type
    public, private and protected parts


  Interfacing

    New method, compiler has major responsibility


  Tasking

    monitor tasks, asynchronous transfer of control, protected types
    low level semaphores


  Misc.

    new generic features
    address arithmetic
    modular arithmetic
    special interest annexes