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: 103376,c406e0c4a6eb74ed X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news2.google.com!proxad.net!newsfeed.icl.net!news-FFM2.ecrc.net!newsfeed00.sul.t-online.de!newsmm00.sul.t-online.de!t-online.de!news.t-online.com!not-for-mail From: Martin Krischik Newsgroups: comp.lang.ada Subject: Re: ADA Popularity Discussion Request Date: Tue, 21 Sep 2004 10:11:18 +0200 Organization: AdaCL Message-ID: <1434159.hBAPArD9Aj@linux1.krischik.com> References: <49dc98cf.0408110556.18ae7df@posting.google.com> <17sx057ro5jw5$.t2qlaeoxg611$.dlg@40tude.net> <1095082522.132276@master.nyc.kbcfp.com> <18ym85v67zof3$.7oqswzjfgswr.dlg@40tude.net> <1095090665.624419@master.nyc.kbcfp.com> <68zmgy3b894u.rs67cy6jjfiq$.dlg@40tude.net> <1164383.Vq7EPUUJyU@linux1.krischik.com> <2177491.OlAk1RxoCA@linux1.krischik.com> Reply-To: krischik@users.sourceforge.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit X-Trace: news.t-online.com 1095759857 07 9268 hyqhX+t6fuiHvkr 040921 09:44:17 X-Complaints-To: usenet-abuse@t-online.de X-ID: SxkJF4ZarezvijWlR0jgmiZbjLJYlyJCjquN2dO6Qvap2m7QYDYPcu User-Agent: KNode/0.7.7 Xref: g2news1.google.com comp.lang.ada:3891 Date: 2004-09-21T10:11:18+02:00 List-Id: Randy Brukardt wrote: > "Martin Krischik" wrote in message > news:2177491.OlAk1RxoCA@linux1.krischik.com... >> Georg Bauhaus wrote: >> >> > Martin Krischik wrote: >> > >> > : Now that you say it: True. Mind you, if space is a problem, you can >> > : always do it the C way: >> > : >> > : String_1 : aliased String = "1"; >> > : String_12 : aliased String = "12"; >> > : String_13 : aliased String = "13"; >> > : >> > : type String_Access is access all String; >> > : type Ragged is array (Integer range <>) of String_Access; >> > : X : constant Ragged := >> > : ( String_1'Access, >> > : String_12'Access, >> > : String_13'Access >> > : ); >> > >> > for constants, >> > >> > X: constant Ragged := >> > ( new String'("1"), >> > ... >> > >> > does just as well, the allocations are performed by the compiler, >> > not at run time :-) >> >> Really! I did not know that! Where does it say in the RM - or is a > compiler >> dependent optimisation. > > The standard really couldn't say it; we only define the semantics of the > operation, not the exact code that it uses. That said, there was an > intention by the Ada 95 design team that this be done, Well it is quite hidden. I did a query at ada-comments I got the following very short answer: ----- See 13.11(24): 24. A default (implementation-provided) storage pool for an access-to-constant type should not have overhead to support deallocation of individual objects. ----- Without the query I would neither found nor understand that chapter. Only now I see that if no deallocation is needed than allocation isn't needed either and the "new" can be optimised away. > and I think that > there is an AARM note to that effect. The AARM is even more difficult to read. > So it isn't surprises that > implementers would make this optimization. (We didn't do it in Janus/Ada, > simply because it didn't seem worth the work -- we hadn't seen any real > usage of it. If customers had asked for it, we would have done it, of > course.) It just might be that customers haven't asked for it because customers have not understand what 13.11(24) actually means. It makes ragged arrays just as easy as in C - if I had only known before. You With Rergards Martin -- mailto://krischik@users.sourceforge.net http://www.ada.krischik.com