-- F393B00.A -- Alert_Foundation -- -- Grant of Unlimited Rights -- -- Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687, -- F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained -- unlimited rights in the software and documentation contained herein. -- Unlimited rights are defined in DFAR 252.227-7013(a)(19). By making -- this public release, the Government intends to confer upon all -- recipients unlimited rights equal to those held by the Government. -- These rights include rights to use, duplicate, release or disclose the -- released technical data and computer software in whole or in part, in -- any manner and for any purpose whatsoever, and to have or permit others -- to do so. -- -- DISCLAIMER -- -- ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR -- DISCLOSED ARE AS IS. THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED -- WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE -- SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE -- OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A -- PARTICULAR PURPOSE OF SAID MATERIAL. --* -- -- FOUNDATION DESCRIPTION: -- This package declares three abstract types for use in C660 series -- tests, Alert, Special_Alert, and Private_Alert. -- It models (in miniature) an application situation in which an -- abstraction is defined in terms of structure (record and operations -- on the record) but not in terms of content (record is null). It -- also models a situation in which an abstraction includes some -- specific, implementation dependent, information. -- -- CHANGE HISTORY: -- 06 Dec 94 SAIC ACVC 2.0 -- --! package F393B00 is type Alert is abstract tagged null record; -- abstract type -- see procedure Handle below procedure Handle (A : in out Alert) is abstract; -- abstract procedure, -- explicitly declared type Private_Alert is abstract tagged private; procedure Handle (PA : in out Private_Alert) is abstract; -- ensures that Private_Alert -- is visibly abstract type Status_Kind is (Practice, Real, Dont_Care); type Urgency_Kind is (Low, Medium, High); type Practice_Alert is new Alert with record Status : Status_Kind := Dont_Care; Urgency : Urgency_Kind := Low; end record; procedure Handle (PA : in out Practice_Alert); -- overrides inherited Handle type Device is (Teletype, Console, Big_Screen); type Special_Alert (Age : Integer) is abstract new Practice_Alert with record Display : Device; end record; procedure Handle (SA : in out Special_Alert) is abstract; -- overrides inherited Handle private subtype Implementation_Detail is Integer range 1..10; type Private_Alert is abstract tagged record Private_Field : Implementation_Detail := 1; end record; end F393B00; --=======================================================================-- package body F393B00 is procedure Handle (PA : in out Practice_Alert) is begin PA.Status := Real; PA.Urgency := Medium; end Handle; end F393B00;