From: stt@houdini.camb.inmet.com (Tucker Taft)
Subject: Re: Doubly linked list.
Date: 1998/12/15
Date: 1998-12-15T00:00:00+00:00 [thread overview]
Message-ID: <F40rpJ.5yB.0.-s@inmet.camb.inmet.com> (raw)
In-Reply-To: 7560vn$21e@romeo.logica.co.uk
Matt Tyler (matt_tyler@hotmail.com) wrote:
: I'm having trouble implementing a Doubly linked list in ada.
: My procedure to add a new singly linked record to the list is (body only)
: List:=new Box'(V,List);
: where V is an integer and List is an access type to box.
: I don't understand how to set another access type in the record to the
: previous record on the list. Can anyone help??
With a doubly linked list, each list element has both a "next" and
a "prev" component, in general. You need to initialize both. In
general, one will be null in the new element.
The following will accomplish the job:
-- Insert on front of list
List := new Box'(V, Next => List, Prev => null);
if List.Next /= null then
-- Make old "first" element point back to new "first"
List.Next.Prev := List;
end if;
: P.S is there a comp.lang.ada faq ???????????
Try www.adahome.com.
: Cheers,
: Matt Tyler
--
-Tucker Taft stt@averstar.com http://www.averstar.com/~stt/
Technical Director, Intermetrics, Inc. Burlington, MA USA
An AverStar Company (www.averstar.com)
next prev parent reply other threads:[~1998-12-15 0:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-12-15 0:00 Doubly linked list Matt Tyler
1998-12-15 0:00 ` Tucker Taft [this message]
1999-01-19 0:00 ` news.oxy.com
1999-01-19 0:00 ` Simon Wright
1999-01-20 0:00 ` news.oxy.com
1999-01-21 0:00 ` Simon Wright
1999-01-21 0:00 ` news.oxy.com
-- strict thread matches above, loose matches on Subject: below --
1993-09-24 17:06 Doubly Linked List Robert Kitzberger
1993-09-24 13:32 John Lorenzen
1993-09-23 16:41 cis.ohio-state.edu!math.ohio-state.edu!caen!usenet.cis.ufl.edu!eng.ufl.ed
1993-09-22 0:24 George C. Harrison, N orfolk State University
1993-09-21 0:47 Gregory Aharonian
1993-09-20 15:14 David Tannen
1993-09-19 22:59 agate!howland.reston.ans.net!europa.eng.gtefsd.com!darwin.sura.net!seas.g
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