From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,5526cbaedf4542a4
X-Google-NewGroupId: yes
X-Google-Attributes: gida07f3367d7,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Received: by 10.68.235.4 with SMTP id ui4mr3607209pbc.3.1330963687310;
        Mon, 05 Mar 2012 08:08:07 -0800 (PST)
Path: 
 h9ni42552pbe.0!nntp.google.com!news1.google.com!goblin2!goblin.stu.neva.ru!aioe.org!eternal-september.org!feeder.eternal-september.org!mx04.eternal-september.org!.POSTED!not-for-mail
From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: ADTs C to Ada
Date: Mon, 05 Mar 2012 16:08:05 +0000
Organization: A noiseless patient Spider
Message-ID: <m2ipijhvyy.fsf@pushface.org>
References: <28640131.3602.1330956581432.JavaMail.geo-discussion-forums@vbw15>
Mime-Version: 1.0
Injection-Info: mx04.eternal-september.org;
 posting-host="dFCm8HWntFqmDIilBLqEJQ";
	logging-data="20729"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX1/uVxS5W3GZKzo1dAbeHm3r8q+x9Ii8rZs="
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (darwin)
Cancel-Lock: sha1:C/7L9BX+goYnSUawUe1GatE4dVQ=
	sha1:hUp/+KFtQFAOFfUOjzGcZ5O6Gkk=
Content-Type: text/plain; charset=us-ascii
Date: 2012-03-05T16:08:05+00:00
List-Id: <comp.lang.ada>

Patrick <patrick@spellingbeewinnars.org> writes:

> I am studying Ada and making progress. The C interface seems straight
> forward enough for functions, strings pointers and such but I am
> having trouble finding any information on how to interface with stucts
> that contain functions.

The thing to be careful of here is what the library does to the
pointer-to-subprogram. It's most likely to store it away somwehere and
call it in a different context, which would mean that the subprogram
might get called without the Ada environment it expects. See my response
in this thread:
https://groups.google.com/forum/?fromgroups#!searchin/comp.lang.ada/.threads/comp.lang.ada/Kl9hmcPMDos/-H_XoJYQvDkJ