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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Intervention needed?
Date: Mon, 25 Mar 2019 21:44:09 +0100
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Xref: reader01.eternal-september.org comp.lang.ada:55965
Date: 2019-03-25T21:44:09+01:00
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On 2019-03-25 20:14, Randy Brukardt wrote:

> I was specifically asking about the common need to have connections between
> containers. It's not likely that a single container is all one needs to
> solve a problem, so one needs ways to refer to elements of one container
> from another.

Example: a relational table searchable by keys K1..KN containing data 
D1..DM. A typical implementation is a map Index->(D1,...,DM) and N maps 
Ki->Index.

> For instance, one might need a index for another container. (For instance,
> to allow lookups by some internal characteristic.) If the main container is
> structured (as in an internal representation of HTML or XML, or a compiler
> symbol table), the index has to be a separate container. Ada provides
> cursors to represent those sorts of interconnections.

Things become especially interesting with forward and backward 
references, transitive references and references marshaled from context 
to context.

> P.S. Sorry about breaking the thread; the message wouldn't post because of
> header limits (too many replies).

References again...

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de