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: 103376,73cb216d191f0fef X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,UTF8 X-Received: by 10.180.212.113 with SMTP id nj17mr828810wic.7.1366373326939; Fri, 19 Apr 2013 05:08:46 -0700 (PDT) Path: hg5ni21856wib.1!nntp.google.com!feeder1.cambriumusenet.nl!feed.tweaknews.nl!85.12.40.131.MISMATCH!xlned.com!feeder3.xlned.com!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!news.stack.nl!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Is this expected behavior or not Date: Fri, 19 Apr 2013 14:09:52 +0200 Organization: cbb software GmbH Message-ID: <84dn4lxu5j$.1mi40bvj8e8tc$.dlg@40tude.net> References: <516e6a0e$0$9505$9b4e6d93@newsspool1.arcor-online.net> <516efa28$0$9518$9b4e6d93@newsspool1.arcor-online.net> <51710936$0$6554$9b4e6d93@newsspool4.arcor-online.net> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: FbOMkhMtVLVmu7IwBnt1tw.user.speranza.aioe.org Mime-Version: 1.0 X-Complaints-To: abuse@aioe.org User-Agent: 40tude_Dialog/2.0.15.1 X-Notice: Filtered by postfilter v. 0.8.2 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Date: 2013-04-19T14:09:52+02:00 List-Id: On Fri, 19 Apr 2013 11:07:05 +0200, Georg Bauhaus wrote: > On 18.04.13 13:52, Dmitry A. Kazakov wrote: >> On Wed, 17 Apr 2013 21:38:28 +0200, Georg Bauhaus wrote: >> >>> On 17.04.13 11:57, Dmitry A. Kazakov wrote: >>> >>>>> If the Ada type system cannot express >>>>> time and space, I'll still consider them >>>>> functional requirements. >>>> >>>> And this should justify conflation of a representation with the type >>>> semantics... surely. >>> >>> Representation is functional, >> >> You should feel obliged to write an AI to disband ARM 7.3. > > Semantics is not restricted to private types. Private types have no semantics? Hint: language semantics /= program semantics >>> Nothing is conflated here because semantics is assignment of meaning, >> >> http://en.wikipedia.org/wiki/Semantics > > Yes, you might want to read it once more: > > "Semantics (from Ancient Greek: σημαντικός sēmantikós) is the study of > meaning. It focuses on the relation between signifiers, like words, > phrases, signs, and symbols, and what they stand for, their denotation." Semantics is not assignment of meaning. "Assignment of meaning" is an act of translation, understanding, cognition. >>> String is a good example. String is an array, and nothing else. >> >> Wrong. String has an array interface. > > No, right. String has the "interface" of array. Period. has /= is >> Operations like Find can be considered a third array interface. > > Confusion starts precisely from considering the mix of language > defined semantics and used defined types. Confusion of what with what? > Go ahead. Tell us how a compiler will check the consistency > of used defined array types with built-in arrays in all required > places in Ada programs; What is consistency of types and why the compiler must check it. Ada RM is silent about that. Anyway, normally, in formal systems or semi-formal ones like Ada programming language is, consistency (using standard meaning of this word) is guaranteed per construction of corresponding entities. Though I don't see how all this is related to array interfaces, built-in or not arrays, string types etc. There are certain requirements any implementation of array interface has to obey. Those are customary written in the RM under "implementation requirements" clauses. >> In many languages strings can be indexed by strings. > > Show me one, http://en.wikipedia.org/wiki/Associative_array >>> The existence of RM A.4.({4,5}) is of no consequence. To hell with it. >> >> In that case show us a way to create unbounded arrays with representation >> guts inside out. > > Ada does not have unbounded arrays and is not going to have them, Thus either your statement that string is an array is wrong or else Unbounded_Array is not string. The choice is yours. > I dare say. Instead, I suggest that you focus on creating/stealing types > useful for text processing, and make them very different---unless you > can finally produce a user-definable array facility 100% compatible > with the known Ada array facility. Their only relation to current String > (the current array) should be subprograms for conversion. How about > that? No idea. The question was how to implement unbounded strings exposing the representation. Do that first. Then the second question would be why on earth one should expose such a representation. The third question is why the RM should mandate this representation prohibiting other representations. >> Your concept simply does not hold. There are simple indisputable facts: >> >> 1. The representation of string object is irrelevant to what string is. > > Again, an occurrence of, and stipulation of truth in, the auxiliary > verb "is", without offering the necessary definitions of (a) its meaning, > (b) a proof of concept. Please, explain how representation aspects are relevant to the notion of strings in programming. That requires, in particular, a proof that all programming languages that deploy strings necessarily use same representation of. >> 2. It is impossible to have one implementation suitable for all string >> objects and all application domains that use strings, e.g. DNA sequencing, >> pattern matching, text processing, compiler construction etc. > > Yes, the impossible string. q.e.d. >>> The existence of RM 3.6 is essential, because of array semantics. >> >> Array semantics? What's that? > > When I declare an array type, RM 3.6 instructs about the meaning. Which is? You are confusing language semantics with program semantics. >> You claimed that semantics is representation. > > Again, a nice occurrence of a rhetorical classic. I said, instead: > > "Representation ... is meaningful, therefore it is semantically important." > "semantics is assignment of meaning," So representation is not semantics/meaning, at least to the programmer, of course, not to the hardware running the program, not to the artist using code printouts as tapestry patterns etc. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de