Object-oriented Software in Ada 95

Appendix A 369
package body Class_Interest_Account is
procedure Interest_Credit( The:in out Interest_Account ) is
begin
Deposit( The, Money(The.Accumulated_Interest) ); --Rounds
The.Accumulated_Interest := 0.00;
end Interest_Credit;
-- Procedure calc_interest
end Class_Interest_Account;
Program delay
delay n.m seconds
delay n.m;
delay until a_time;
declare
use Ada.Calendar;
begin
delay until time_of(2000,1,1,0.0);
-- 24 Hours
end;
Task
task type Task_Factorial is
entry Start( F:in Positive );
entry Finish( R:out Positive );
end Task_Factorial;
--Specification
--Rendezvous
--Rendezvous
task body Task_Factorial is --Implementation
Fact : Positive; Answer : Positive := 1;
begin
accept Start( F:in Positive) do Fact := F; end Start;
for I in 2 .. Fact loop Answer := Answer * I; end loop;
accept Finish( R:out Positive ) do R:=Answer; end Finish;
end Task_Factorial;
Communication with a task
procedure Main is
Factorial : Task_Factorial;
Res : Natural;
begin
Factorial.Start(5); Put("Factorial 5 is ");
Factorial.Finish(Res); Put( Res, Width=>4 ); New_Line;
end Main;
Rendezvous
select statement select with else select with delay
© M A Smith - May not be reproduced without permission