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 10.68.46.193 with SMTP id x1mr21024138pbm.7.1319322196771; Sat, 22 Oct 2011 15:23:16 -0700 (PDT) Path: c1ni1334pbr.0!nntp.google.com!news2.google.com!npeer01.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!nx02.iad01.newshosting.com!newshosting.com!news2.euro.net!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: Sun, 23 Oct 2011 00:23:14 +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> <4d97ced2-1695-4352-926c-2070f9ccbbf1@o19g2000vbk.googlegroups.com> <1cchjqhfjqo2l$.1s951jo0p9w8c.dlg@40tude.net> <1xuiads70kb6s$.odhmr2fg9b0z.dlg@40tude.net> <1ljblwrul8pmp$.1crge3eb0lhon.dlg@40tude.net> NNTP-Posting-Host: GNfGRARmUQU94N9UnyMBHA.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:14157 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Content-Transfer-Encoding: Quoted-Printable Date: 2011-10-23T00:23:14+02:00 List-Id: Le Sat, 22 Oct 2011 09:54:07 +0200, Dmitry A. Kazakov = a =C3=A9crit: >> Conclusion: the interface could not remain the same, and different >> interface, means different type. > > Here you confirm that LSP does work. But Ada does not base its type = > system > on LSP. There cannot be any usable LSP-conform type system. It actually do. But it will never with a broken design, obviously. With = = the above example of sub=E2=80=91typing a container for a subtype elemen= t type, = the trouble does not come with Ada, but with the merge of two interfaces= : = input interface and output interface. It's a rule of thumb for me, to = separate both, because after some experiences, I've learned sooner or = later, you face troubles if you do not distinguish both (*). If you have= = two interfaces, one for input and one for output, there is no more = trouble, you can subtype the Input interface to follow an element subtyp= e. = If you don't want to separate both, then you just can't subtype this way= . = You have to make a choice, and that's not Ada's fault, that's the domain= 's = =E2=80=9Cfault=E2=80=9D. Although Jean-Pierre underlined they are with Ada, some matters which ar= e = in practice above some others (which is true and OK to notice), nothing = in = Ada prevents you from using the good design, even if that design does = match Ada niches and typical use cases (you may just have to not tell = anyone, cheese). (*) I like to redesign sometime, with a read only abstract T1 and a = concrete derived read/write T2. If you really believe Ada subtypes, *as Ada allows to use it*, does not = = conform to the substitution principle, can you provide an example ? = Personally I don't see a trouble if the language does not allow you to d= o = something it would not be able to handle. You know=E2=80=A6 better not r= un = anything at all, than running an erroneous thing. Please Dmitry, could write down once a whole, all you comments about Ada= . = Even do it with a funny title, kind of =E2=80=9CAda criticisms (and _pro= posals_)=E2=80=9D = if you feel it. At least this would help to follow the story, because = that's easy to forget what was already said and what was not, along with= = rationales and examples=E2=80=A6 I have a strange feeling of repeating m= yself, = sometime, when I reply to you when you complain. Also, this would be an = = opportunity for better formalization of your comments. I don't enjoy tal= ks = which too much seems to be about taste when the subject is a rather form= al = thing (the language) and also when the subject is something into which = many people invested a lot. Your paper could also be opened for comments= = (just like Ada do with its definition). An opportunity for better, longe= r = and clearer clarifications in a single reference place would be nice. -- = =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