Object-oriented Software in Ada 95

368 Appendix A
The following code will execute until the condition sunny is met.
loop --Repeat
Work; -- Perform work
exit when Sunny; -- exit from loop when sunny
end loop; --
Class declaration and implementation
package Class_Account is
type Account is tagged private;
type Money is delta 0.01 digits 8; --
subtype Pmoney is Money range 0.0 .. Money'Last; --+ve Money
procedure Deposit( The:in out Account; Amount:in Pmoney );
procedure Withdraw( The:in out Account;
Amount:in Pmoney; Get:out Pmoney );
function Balance( The:in Account ) return Money;
private
type Account is tagged record --Instance variables
Balance_Of : Money := 0.00; --Amount on deposit
Min_Balance : Money := 0.00; --Minimum Balance
end record;
end Class_Account;
package body Class_Account is
procedure Deposit( The:in out Account; Amount:in Pmoney ) is
begin
The.Balance_Of := The.Balance_Of + Amount;
end Deposit;
-- Procedures withdraw and balance
end Class_Account;
Inheritance
with Class_Account;
use Class_Account;
package Class_Interest_Account is
type Interest_Account is new Account with private;
type Imoney is digits Money'digits+2; --
procedure End_Of_Day( The:in out Interest_Account );
procedure Interest_Credit( The:in out Interest_Account );
procedure Interest_Accumulate( The:in out Interest_Account;
Amount: in Imoney );
private
Daily_Interest_Rate: constant Imoney := 0.000133680617;
type Interest_Account is new Account with record
Accumulated_Interest : Imoney := 0.00; --To date
end record;
The_Interest_Rate : Imoney := Daily_Interest_Rate;
end Class_Interest_Account;
© M A Smith - May not be reproduced without permission