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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Received: by 2002:a6b:1a8e:: with SMTP id a136-v6mr7363109ioa.66.1530373387562; Sat, 30 Jun 2018 08:43:07 -0700 (PDT) X-Received: by 2002:aca:f495:: with SMTP id s143-v6mr155723oih.7.1530373387451; Sat, 30 Jun 2018 08:43:07 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!feeder.erje.net!1.eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed7.news.xs4all.nl!85.12.16.70.MISMATCH!peer03.ams1!peer.ams1.xlned.com!news.xlned.com!peer03.am4!peer.am4.highwinds-media.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!u78-v6no1422442itb.0!news-out.google.com!z3-v6ni1120iti.0!nntp.google.com!u78-v6no1422440itb.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Sat, 30 Jun 2018 08:43:07 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=50.66.161.135; posting-account=lzqe5AoAAADHhp_gregSufVhvwu22fBS NNTP-Posting-Host: 50.66.161.135 References: <993f28de-6a64-480b-9c6e-d9714bcdef0d@googlegroups.com> <167bec10-2a52-4c79-958d-91faadad915b@googlegroups.com> <2d6a5ab7-812f-47a9-a958-44177a3cf203@googlegroups.com> <64a526cb-e6d5-44a6-b446-5b652ebe60ca@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <845ed7d6-f0c0-4c6e-834c-eea8f2ad1792@googlegroups.com> Subject: Re: Ada lacks lighterweight-than-task parallelism From: Brad Moore Injection-Date: Sat, 30 Jun 2018 15:43:07 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Received-Bytes: 3362 X-Received-Body-CRC: 2193959396 Xref: reader02.eternal-september.org comp.lang.ada:53478 Date: 2018-06-30T08:43:07-07:00 List-Id: I don't think that would fit into the language very well, and I dont think = this is particularly appealing to me, though at one time I was suggesting t= hat we could apply aspects such as parallel and other controls to a locally= declared subtype, we moved away from that idea. We have "reverse" syntax f= or loops already which specifies an order. It would be inconsistent to some= times specify the order on the loop, and sometimes somewhere else. It also = seems like it would be messy for ADT's such as containers. Sometimes you wa= nt to iterate through a type sequentially, for example when the work to be = performed per iteration is very small and not worth doing in parallel, and = sometimes you want to specify parallel execution, if you know that there is= significant processing required for each iteration. You might have a conta= iner with many elements. It sounds like you'd have to declare two container= objects, (one parallel, and one sequential), and then copy all the element= s from one to the other whenever you wanted to switch from sequential to pa= rallel iteration or vice versa, when really you only want or need a single = container object. Similarly, you might want to iterate through an enumeration with a particul= ar order for one loop, and a different order for another loop. It seems to = be better to apply the hint to the loop construct rather than the iterator = type, which is also consistent with other approaches such as in OpenMP and = Cilk. Brad Moore