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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,39579ad87542da0e X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit X-Received: by 10.180.105.161 with SMTP id gn1mr5485811wib.6.1369279405348; Wed, 22 May 2013 20:23:25 -0700 (PDT) Path: fw11ni1136wic.0!nntp.google.com!feeder1.cambriumusenet.nl!feed.tweaknews.nl!85.12.40.130.MISMATCH!xlned.com!feeder1.xlned.com!border2.nntp.ams.giganews.com!border3.nntp.ams.giganews.com!border1.nntp.ams.giganews.com!nntp.giganews.com!news.panservice.it!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Seeking for papers about tagged types vs access to subprograms Date: Wed, 15 May 2013 15:00:32 +0200 Organization: cbb software GmbH Message-ID: <1nkyb845dehcu.1sd90udwsrpdu.dlg@40tude.net> References: <1bfhq7jo34xpi.p8n2vq6yjsea.dlg@40tude.net> <12gn9wvv1gwfk.10ikfju4rzmnj.dlg@40tude.net> <1oy5rmprgawqs.1jz36okze0xju$.dlg@40tude.net> <1q2ql1e4rcgko.diszzq1mhaq8$.dlg@40tude.net> <518dedd4$0$6581$9b4e6d93@newsspool3.arcor-online.net> <1um7tijeo609b$.1gtdijp0acfmn$.dlg@40tude.net> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: FbOMkhMtVLVmu7IwBnt1tw.user.speranza.aioe.org Mime-Version: 1.0 X-Complaints-To: abuse@aioe.org User-Agent: 40tude_Dialog/2.0.15.1 X-Notice: Filtered by postfilter v. 0.8.2 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Date: 2013-05-15T15:00:32+02:00 List-Id: On Wed, 15 May 2013 07:20:23 -0400, Peter C. Chapin wrote: > On Tue, 14 May 2013, Dmitry A. Kazakov wrote: > >> procedure Foo; > > This procedure does nothing unless it has side effects. If so, then those > side effects entail operations on values of a particular type. Nevertheless it is an operation that does not refer to any particular type. >> Value is not a programming language term, it belongs to the application >> domain. Value is the meaning attributed to the state of a typed object in >> some context. >> >> E.g. >> >> Salary : Buckazoid := 1; >> >> Salary is meant to have the value of 1 Buckazoid. > > A type is a pair of sets: a set of values and a set of operations defined > over those values (for example as functions taking items from the first > set as a parameter). Either set can be empty. In any case "value" is most > certainly a programming language term. type Employee is ...; How is employee a language term? task type Driver is ...; Show me an RM section which defines the values of this type. And the simplest possible example why the language has nothing to do with values is this: type Some_Transcendental_Numbers is (e, Pi, Euler); What is the value of e? > You can't talk about a type without > talking about the values that inhabit that type (again, could be an empty > set in certain special cases). This is what I said in response to Randy. That type, operations, values cannot be separated to each other. Neither is more or less fundamental than other. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de