Object-oriented Software in Ada 95

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Object
Preface
An instance of a class. An object has a state that is interrogated / changed by
methods in the class. The object mike that is an instance of Account is
declared as follows:
Mike: Account;
Overloading
When an identifier can have several different meanings. For example, the
procedure Put in the package Ada.Text_Io has several different
meanings. Output an instance of a Character, output an instance of a
String.
Put("Hello Worl"); Put('d' );
Overriding
Polymorphism
The ability to send a message to an object whose type is not known at
compile-time. The method selected depends on the type of the receiving
object. For example the message 'Display' is sent to different types of
picture elements that are held in an array.
Display( Picture_Element(I) );
Rendezvous
Representation
clause
The interaction that occurs when two tasks meet to synchronize and possibly
exchange information.
Directs the compiler to map a program item onto specific hardware features
of a machine. For example, location is defined to be at address
16#046C#.
Mc_Address : constant Address :=
To_Address( 16#046C# );
Location : Integer;
for Location'Address use Mc_Address;
Static binding
Type
The binding between an object and the message that it is sent to it is known
at compile-time.
A type defines a set of values and the operations that may be performed on
those values. For example, the type Exam_Mark defines the values that may
be given for an exam in English.
type Exam_Mark is range 0 .. 100;
English : Exam_Mark
© M A Smith - May not be reproduced without permission