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 X-Received: by 2002:a24:75c2:: with SMTP id y185-v6mr2027558itc.35.1521651890503; Wed, 21 Mar 2018 10:04:50 -0700 (PDT) X-Received: by 2002:a9d:5906:: with SMTP id t6-v6mr723139oth.2.1521651890399; Wed, 21 Mar 2018 10:04:50 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!news.uzoreto.com!weretis.net!feeder6.news.weretis.net!feeder.usenetexpress.com!feeder-in1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!199-v6no2052957itl.0!news-out.google.com!d3-v6ni1255itf.0!nntp.google.com!199-v6no2052954itl.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Wed, 21 Mar 2018 10:04:50 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=47.185.233.194; posting-account=zwxLlwoAAAChLBU7oraRzNDnqQYkYbpo NNTP-Posting-Host: 47.185.233.194 References: User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <9ed9edb1-3342-4644-89e8-9bcf404970ee@googlegroups.com> Subject: Re: Ada-Oriented GUI From: "Dan'l Miller" Injection-Date: Wed, 21 Mar 2018 17:04:50 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Xref: reader02.eternal-september.org comp.lang.ada:51099 Date: 2018-03-21T10:04:50-07:00 List-Id: On Wednesday, March 21, 2018 at 11:27:56 AM UTC-5, Dmitry A. Kazakov wrote: > On 21/03/2018 15:30, Dan'l Miller wrote: >=20 > > Rx is directly aiming at solving that entire problem space. Quite well= , btw, especially regarding concurrent scheduler-based handling events arri= ving haphazard from drastically-different concerns: human GUI events, appl= ication lifetime events, network traffic arrival events, asynchronous OS ev= ents (e.g., filesystem I/O), and so forth. >=20 > Scheduling implies that order of events is not preserved, right? How=20 > consistency is achieved? The order of each sequence of events from a single-threaded sender is stric= tly preserved in Rx (including under the numerous filtering mechanisms). C= onversely, there is no order to preserve between different single-threaded = senders. E.g., async filesystem I/O events can interleave GUI human-activi= ty events can interleave application-lifecycle events can interleave networ= k packet-arrival events arbitrarily and differently each execution. Having= a software architecture that obfuscates this natural lack of any inter-sen= der ordering is what causes deep & severe & pernicious bugs (actually worse= that bugs, usually fatal-to-the-feature back-to-the-drawingboard nonrealti= me design flaws and much head-scratching). Having a software architecture = that effectively says, =E2=80=9CHey, we've done the heavy lifting of flowin= g all these rivers of data to you without ruining them; now you need to do = the hey-dummy-don't-ruin-them-by-comingling-them-illogically too, such as i= mplicitly expecting a GUI event to arrive ahead of a network packet or vice= versa, or implicitly expecting an app-lifecycle event to never arrive befo= re an async filesystem I/O event.=E2=80=9D Rx brings =E2=80=A2composable s= ystem=E2=80=A2 to realtime event arrival by (nearly-)demanding that the arb= itrary-order events are blatantly obvious *between* different sequences (by= making the preserved-order events blatantly obvious *within* any one seque= nce).