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=unavailable autolearn_force=no version=3.4.4 Path: border2.nntp.dca3.giganews.com!backlog4.nntp.dca3.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!ottix-news.ottix.net!newsswitch.lcs.mit.edu!nntp.TheWorld.com!.POSTED!not-for-mail From: Robert A Duff Newsgroups: comp.lang.ada Subject: Re: abstract types and subprograms Date: Sat, 24 May 2014 14:49:55 -0400 Organization: The World Public Access UNIX, Brookline, MA Message-ID: References: <1xpqa3ak5k59r$.ncugtl37io47.dlg@40tude.net> NNTP-Posting-Host: shell01.theworld.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: pcls7.std.com 1400957393 21062 192.74.137.71 (24 May 2014 18:49:53 GMT) X-Complaints-To: abuse@TheWorld.com NNTP-Posting-Date: Sat, 24 May 2014 18:49:53 +0000 (UTC) User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (irix) Cancel-Lock: sha1:iwL2Dj/WIAutpV/cWPx0UCp0as4= X-Original-Bytes: 1728 Xref: number.nntp.dca.giganews.com comp.lang.ada:186603 Date: 2014-05-24T14:49:55-04:00 List-Id: "Dmitry A. Kazakov" writes: > I disagree. There is no need for instances of abstract objects, as there is > no need of extension aggregates. There should be proper constructors > instead. You've said that many times, but I've never seen a detailed description of what you mean. (Sorry if I missed it -- I don't read newsgroups regularly.) Can you please show us your language design for "proper constructors"? It seems like something like extension aggregates are needed -- you need a way to create an object of a type, given the value of an ancestor, and the values of the extension components. - Bob