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-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,b6e97963d32ee242
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2003-05-28 17:55:39 PST
Path: archiver1.google.com!postnews1.google.com!not-for-mail
From: aek@vib.usr.pu.ru (Alexander Kopilovitch)
Newsgroups: comp.lang.ada
Subject: Re: The old "Object.Method" syntax debate
Date: 28 May 2003 17:55:39 -0700
Organization: http://groups.google.com/
Message-ID: <e2e5731a.0305281655.6cf38e6b@posting.google.com>
References: 
 <254c16a.0305210726.485125de@posting.google.com><vcn7svfjbannd6@corp.supernews.com>
 <3eccdf77$1@epflnews.epfl.ch> <vcprq15q8m344e@corp.supernews.com>
 <3ecdd296$1@epflnews.epfl.ch> <bakm9r$oh3n$1@ID-77047.news.dfncis.de>
 <e2e5731a.0305231035.17962520@posting.google.com>
 <3ED056CB.8000200@attbi.com>
 <e2e5731a.0305271902.4993e9ea@posting.google.com>
 <3ed46d7a.994560@news.btclick.com>
NNTP-Posting-Host: 62.152.82.100
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Trace: posting.google.com 1054169739 10295 127.0.0.1 (29 May 2003 00:55:39
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: 29 May 2003 00:55:39 GMT
Xref: archiver1.google.com comp.lang.ada:37961
Date: 2003-05-29T00:55:39+00:00
List-Id: <comp.lang.ada>

>>The name space for attributes is too important language resource, it should
>>not be given out freely for general use.
>>  How about another character instead of apostrophe (or dot) for user-defined
>>attributes? For example, there is quite popular # (read "join" for this purpose):
>> Object#Operation 
>>("controlling object" somehow associates with "base" -:)
>
>Nah - that's ugly :-)

Well, perhaps Microsoft wouldn't say so -:)

  Anyway, I just imagined another notation for that purpose, and it seems
worth of discussion: dot-qualified attribute Method, i.e.

  Object'Method.Operation

for example:

  type T is ... ;
  function F(P : T; Q : Integer) return Integer;
  X : T;
  Actual_Q : Integer;
  ...

  X'Method.F(Actual_Q);

For me, this notation looks quite straight. Indeed, one may think that the
attribute Method returns a record -- method table, like in C++ code.
  (If you will argue that the attribute part in this notation is obviously
redundant, I will reply that you English all the time use articles "a" and
"the", which seem no less redundant for Russian native speaker, like me -:) .

  Furthemore, with this approach we may easily provide a denotation for the
corresponding abstraction, that is, unified notation for a component and
a method; all we need for this is another attribute Property, which should be
used the same way:

for both

  type T is ... ;
  function F(P : T) return Integer;

and

  type T is record 
     F : Integer;
     ...
  end record;

we can write:

  X : T;
  R : Integer;
  ...

  R := X'Property.F;


(This approach does not provide assignment to a property; for writable
properties we can rely upon controlled data components.)



Alexander Kopilovitch                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia