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,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,5bcc293dc5642650 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,UTF8 Received: by 10.68.8.135 with SMTP id r7mr15186401pba.8.1319201593147; Fri, 21 Oct 2011 05:53:13 -0700 (PDT) Path: d5ni39575pbc.0!nntp.google.com!news2.google.com!goblin1!goblin.stu.neva.ru!feeder.news-service.com!aioe.org!.POSTED!not-for-mail From: =?utf-8?Q?Yannick_Duch=C3=AAne_=28Hibou57?= =?utf-8?Q?=29?= Newsgroups: comp.lang.ada Subject: Re: Why no Ada.Wide_Directories? Date: Fri, 21 Oct 2011 14:53:11 +0200 Organization: Ada @ Home Message-ID: References: <9937871.172.1318575525468.JavaMail.geo-discussion-forums@prib32> <418b8140-fafb-442f-b91c-e22cc47f8adb@y22g2000pri.googlegroups.com> <7156122c-b63f-487e-ad1b-0edcc6694a7a@u10g2000prl.googlegroups.com> <409c81ab-bd54-493b-beb4-a0cca99ec306@p27g2000prp.googlegroups.com> <1rlz5gwqmeizn$.fwqpl0mhzf54$.dlg@40tude.net> <1w7i4ekc7yvjx$.60o908ry5lhc$.dlg@40tude.net> NNTP-Posting-Host: q7N8AolrQHo0KApF9Qa31g.user.speranza.aioe.org Mime-Version: 1.0 X-Complaints-To: abuse@aioe.org User-Agent: Opera Mail/11.51 (Linux) X-Notice: Filtered by postfilter v. 0.8.2 Xref: news2.google.com comp.lang.ada:14127 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Content-Transfer-Encoding: Quoted-Printable Date: 2011-10-21T14:53:11+02:00 List-Id: Le Thu, 20 Oct 2011 19:35:21 +0200, Dmitry A. Kazakov = a =C3=A9crit: > No, FP is just too low level: procedural decomposition. Type systems > correspond to the categories - a better and more capable mathematics =3D= > > safer design. Another fundamental problem of FP is a wrong premise abo= ut > being stateless. Computing is solely about states. You run a program t= o > have its side effects, there is no other reason for doing that. You should write every thing down you know (your though about Ada, FP, a= nd = so on). Would be useful to you and others. >> What's missing from Interface type introduced with Ada 2005 ? > > 1. Most Ada types do not have interfaces Eiffel has this, and this is 1) not perfect (may lead to performance = issue) 2) rarely used in practice > 2. Ada interface cannot be inherited from a concrete type You can have a concrete implementation, why is that not enough ? > 3. Ada interface cannot have implementation Derived types can. Why is that a trouble is one inheritance level is = purely abstract ? > 4. Ada interface does not support ad-hoc supertypes Can you tell more with an example ? (I don't know what supertypes are) Feels like to need an even higher level language than Ada is. There are = = some, however most are interpreted language, and are not targeting safet= y = (in the wide meaning) as much as Ada too. > Not an issue. Scalar types may have interfaces at zero time/space cost= . = > You > don't need to embed tag into by-value types. This is possible indeed, but at the cost of separate compilation. = SmallEiffel did this, but was relying on overall program analysis, which= = were compiled as a whole. Some other Eiffel implementation using separat= e = compilation, could not optimize. If you make it part of the language = standard, you are imposing implementation requirements beyond the = reasonable. Very big applications need separate compilation. Although = attempted and suggested by Bertrand Meyer, Eiffel applications never = scaled large fine (except with global analysis, but re-compiling a whole= = application whenever something change, although they may be some trick t= o = avoid real recompilation of everything, is not an acceptable option for = = Ada niches). >>> Any syntax sugar (prefix notation, infix operations, >>> assignments, indexing, member extraction, aggregates, entries, >>> attributes) shall be operations. >> Are you sure you are not confused between concrete syntax and abstrac= t >> syntax ? > > I don't understand this. The problem is that, for example, for the rec= ord > type T and its member A, the ".A" is not the operation of T, because = > record > is not an interface. A'First is not an operation of array. ":=3D" is n= ot an > operation (doubly dispatching) of its left and right sides etc. Same feeling as above. Seems you are looking for something which is high= er = level than Ada is. There are some pleasant language in this area, but = which just end to be cool toys (although still cool to play with ;) ). M= ay = be worth to recall Ada is not a modeling language, but an implementation= = language with features to enforce safety as much as possible. >> This is not a language topic, instead, a technology level topic. I fe= el >> runtime check is a reasonable fall-back for what cannot be statically= >> checked in th actual state of the technology. > > No, it is inconsistent and unreasonable. Static checks are meant to = > detect bugs. Bug is either there or not, independently on whether the = = > program is > running, not running, will ever run. Easy to say, less to do. You did not demonstrate this is not related to = = actual technology, you just complained it is not as you wish. Sorry if I've not replied to each point, to keep it short. I often agree= = with many points you sometime raised about Ada. There, I feel you are = going to far for what Ada is intended to. You are not noticing any = inconsistencies in existing features, you are requiring new features. -- = =E2=80=9CSyntactic sugar causes cancer of the semi-colons.=E2=80=9D [Ep= igrams on = Programming =E2=80=94 Alan J. =E2=80=94 P. Yale University] =E2=80=9CStructured Programming supports the law of the excluded muddle.= =E2=80=9D [Idem] Java: Write once, Never revisit