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Date: 28 Jan 93 08:07:43 GMT
From: paster@dna.lth.se (Christian S. Collberg)
Subject: Re: private types and recompilation
Message-ID: <1993Jan28.080743.29006@lth.se>
List-Id: <comp.lang.ada>

In article <9301271722.aa25516@Paris.ics.uci.edu> kanderso@mabillon.ICS.UCI.EDU
 (Kenneth Anderson) writes:
>In comp.lang.ada you write:
>
>>When Ada 83 was designed, why did the designers choose to put
>>the details of private types in package specifications, rather than
>>in package bodies (which is more in the spirit of information hiding, and
>>better supports independent compilation).
>
>I'm not sure, but I think because the compiler needs to know the size
                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>of the types so that it can allocate space for parameters in the
^^^^^^^^^^^^^
>subprograms that are defined in the spec.
>
>


Yes, this is correct. See my thesis "Flexible Encapsulation" (Yes, this is a
blatant plug :-)) for a description of an Ada-like language (Zuse) which --
through the use of novel translation techniques -- allows private parts of
hidden types to be hidden within package bodies.

Christian
-- 
Christian.Collberg@dna.lth.se
Department of Computer Science, Lund University, BOX 118, S-221 00 LUND, Sweden