From: Mart van de Wege <mvdwege@gmail.com>
Subject: Re: Getting the index for an element in mutually referencing containers
Date: Thu, 09 Mar 2017 17:02:02 +0100
Date: 2017-03-09T17:02:02+01:00 [thread overview]
Message-ID: <86efy630cl.fsf@gaheris.avalon.lan> (raw)
In-Reply-To: 86k27y314h.fsf@gaheris.avalon.lan
Mart van de Wege <mvdwege@gmail.com> writes:
> Egil H H <ehh.public@gmail.com> writes:
>
>> On Thursday, March 9, 2017 at 2:50:03 PM UTC+1, Mart van de Wege wrote:
>>>
>>> Children : Offspring.Vector := Offspring.To_Vector(4);
>>>
>>> Put(Integer(Father.Children.Find_Index(Child)));
>>
>>
>> To_Vector adds empty elements to your list of Children, so Find_Index
>> fails (probably dereferencing null or other erroneouse memory access)
>> when trying to compare them to the Child. Removing the call to
>> To_Vector seems to work as expected...
>
> Aargh. So Find and Find_Index don't just skip empty elements, but die on
> them? *That* was not clear from my reading of the spec.
>
> And yes, in actual practice I expect to have sparse Vectors with a few
> gaps not holding an Element. So how do I deal with this?
>
Hmm. Given that Person objects and their derivatives aren't very large,
I could just prefill the Vector with Person objects. As long as I don't
set any of their parameters, they will represent *potential* siblings.
This feels like a hack though.
Mart
--
"We will need a longer wall when the revolution comes."
--- AJS, quoting an uncertain source.
next prev parent reply other threads:[~2017-03-09 16:02 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-09 13:45 Getting the index for an element in mutually referencing containers Mart van de Wege
2017-03-09 15:25 ` Egil H H
2017-03-09 15:45 ` Mart van de Wege
2017-03-09 16:02 ` Mart van de Wege [this message]
2017-03-09 16:11 ` Egil H H
[not found] ` <ly7f3xedp4.fsf@pushface.org>
[not found] ` <86k27xpikd.fsf@gaheris.avalon.lan>
[not found] ` <lywpbxc9my.fsf@pushface.org>
[not found] ` <86wpbxneuz.fsf@gaheris.avalon.lan>
[not found] ` <o9vcbp$t0t$1@franka.jacob-sparre.dk>
2017-03-11 6:45 ` Mart van de Wege
2017-03-11 8:40 ` Simon Wright
2017-03-11 8:58 ` Dmitry A. Kazakov
2017-03-11 11:21 ` Simon Wright
2017-03-11 14:18 ` Dmitry A. Kazakov
2017-03-11 20:05 ` Simon Wright
2017-03-11 20:52 ` Dmitry A. Kazakov
2017-03-11 21:46 ` Simon Wright
2017-03-11 22:37 ` Niklas Holsti
2017-03-12 8:22 ` Simon Wright
2017-03-12 9:38 ` G.B.
2017-03-12 11:21 ` Simon Wright
2017-03-13 10:29 ` Alejandro R. Mosteo
2017-03-12 8:20 ` Dmitry A. Kazakov
2017-03-12 11:30 ` Simon Wright
2017-03-12 11:55 ` Dmitry A. Kazakov
2017-03-12 16:44 ` Simon Wright
2017-03-12 17:42 ` Dmitry A. Kazakov
2017-03-13 19:55 ` Randy Brukardt
2017-03-13 20:53 ` Dmitry A. Kazakov
2017-03-14 20:40 ` Randy Brukardt
2017-03-15 8:44 ` Dmitry A. Kazakov
2017-03-15 20:12 ` Randy Brukardt
2017-03-16 2:59 ` Paul Rubin
2017-03-16 9:04 ` Dmitry A. Kazakov
2017-03-13 23:25 ` Simon Wright
2017-03-14 8:25 ` Dmitry A. Kazakov
2017-03-12 1:36 ` Randy Brukardt
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