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=2.2 required=5.0 tests=BAYES_00,FROM_WORDY, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,ee1a8b8db84c88f X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!news.maxwell.syr.edu!border1.nntp.dca.giganews.com!local01.nntp.dca.giganews.com!nntp.rcn.net!news.rcn.net.POSTED!not-for-mail NNTP-Posting-Date: Sat, 20 Aug 2005 17:47:58 -0500 Reply-To: "Frank J. Lhota" From: "Frank J. Lhota" Newsgroups: comp.lang.ada References: <4301ab29$0$6989$9b4e6d93@newsread2.arcor-online.net> Subject: Re: Ada exception block does NOT work? Date: Sat, 20 Aug 2005 18:47:58 -0400 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.2670 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2670 Message-ID: NNTP-Posting-Host: 209.6.185.133 X-Trace: sv3-RkVzeefScpQg4eFy7usMfLsfv8bKakWS0GdKqPGAg7aD4DBKOB4dD7mMETNidcJnOEEqLM06I/S/5vf!pEMAyW6p1lm4VsqiKkoY54WUWFS4eB3isOTQfgmolT3kdDzkdKig+MWuhynWudH2 X-Complaints-To: abuse@rcn.net X-DMCA-Complaints-To: abuse@rcn.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: g2news1.google.com comp.lang.ada:4227 Date: 2005-08-20T18:47:58-04:00 List-Id: "Robert A Duff" wrote in message news:wccslx4gumc.fsf@shell01.TheWorld.com... > ... > To me, "pointer" does not imply "a single machine address". > To me, "pointer" means something that can point at things, > and that includes fat pointers, pointers containing array > dope, pointers represented as offsets instead of addresses, > double indirections, &c. Thats fine, but also understand that to many others, "pointer" does mean "a single machine address". It certainly does not hurt to introduce a new term to avoid potential misunderstandings. > To me, "pointer" and "reference" are synonymous. OK, but just be aware that in C++, "pointer" and "reference" are not synonyms. > And "address" or "machine address" can be used for the hardware-level > concept. > > An index into an array can be used as a pointer to a particular > array element. So the number 3 can be thought of as a pointer into any array indexed by a integer. An interesting concept, but this is certainly a non-standard use of the term "pointer". > Ada evolved from Pascal, and Pascal called them pointers. > In Pascal, there was no requirement or implication that > they must be a single machine address. There is no need > for array dope in Pascal, but adding array dope doesn't seem > like it requires renaming the whole concept. For the record, I know of no Pascal compiler that implements a pointer as anything other than a machine address. >> As for Integer, you're quite right, but it's also quite natural to use >> that name (or a shortened form of it) for such a subset. Such a usage is >> quite common in computer languages; see FORTRAN (1955?) for an >> example. What would be a better name for such a type? > > I'd use "Integer" for what Lisp calls "bignums" -- integers that can > grow without bound (except of course you can run out of memory, > but that's true of Strings and whatnot, too. I'd call the integer type > that is based on the hardware (e.g. 32-bit integers) "Machine_Integer". > And I wouldn't put it in a package called "Standard" and I wouldn't > make it automatically visible everywhere. > > I think one ought to be allowed to say: > > type T is range 1..10**100; > > Portably. Now that is an interesting concept. I am fond of divorcing the language from platform constrains when practical. There are, however, some practical concerns about this proposal. An Ada 'bignum' type would undoubtedly be a controlled type, introducing more overhead than one would expect in a scalar type. -- "All things extant in this world, Gods of Heaven, gods of Earth, Let everything be as it should be; Thus shall it be!" - Magical chant from "Magical Shopping Arcade Abenobashi" "Drizzle, Drazzle, Drozzle, Drome, Time for the this one to come home!" - Mr. Lizard from "Tutor Turtle"