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=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,9d8db3defac005a2 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-11-17 10:38:20 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!canoe.uoregon.edu!hammer.uoregon.edu!skates!not-for-mail From: Stephen Leake Newsgroups: comp.lang.ada Subject: Re: Renaming an abstract function Date: 17 Nov 2001 13:33:03 -0500 Organization: NASA Goddard Space Flight Center Message-ID: References: <9t1lp1$16unne$1@ID-25716.news.dfncis.de> NNTP-Posting-Host: anarres.gsfc.nasa.gov Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: skates.gsfc.nasa.gov 1006022127 4214 128.183.220.71 (17 Nov 2001 18:35:27 GMT) X-Complaints-To: dscoggin@cne-odin.gsfc.nasa.gov NNTP-Posting-Date: 17 Nov 2001 18:35:27 GMT User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.7 Xref: archiver1.google.com comp.lang.ada:16647 Date: 2001-11-17T18:35:27+00:00 List-Id: adam@irvine.com (Adam Beneschan) writes: > Stephen Leake wrote in message news:... > > "Nick Roberts" writes: > > > > > When given the program: > > > > > > package Test1 is > > > type T is abstract tagged limited private; > > > function P (X, Y: in T) return T is abstract; > > > function "*" (A, B: in T) return T renames P; -- error line > > > private > > > type T is abstract tagged limited null record; > > > end; > > > > > > GNAT 3.12p on Windows 95 returns the error message: > > > > > > function that returns abstract type must be abstract > > > > > > Is this a bug in: (a) GNAT; (b) the RM95; or (c) my brain? > > > > Same error in gnat 3.14 (you should at least upgrade to 3.13p). > > > > RM 8.5.4 (2) says: > > > > 2. subprogram_renaming_declaration ::= > > subprogram_specification renames callable_entity_name; > > > > The term "callable_entity_name" is not mentioned elsewhere in the > > reference manual, which I find odd. > > Note that "callable_entity" is in italics, while "name" is not. Well, not in the info version :). Guess there's a use for html, after all :). > In RM notation, that means that the language expects the syntax of a > "name" (defined in 4.1), while "callable_entity" is a description > that tells you what the name has to represent. I guess if you're > searching a text file version of the RM, there's probably no > indication that part of it is in italics. Yes; "info format" is ASCII with hyperlinks. Nice for reading from Emacs. But it does lose the italics. Hmm, Emacs 21.1 can probably do a better job of displaying the html version; I'll try that. > "callable entity" is easily found in the index. Ah. I didn't think of that. > A "callable entity" is defined (in 6(2)) to be a subprogram or > entry. Thus an abstract subprogram is a callable entity even though > you can't really call it. Ok. > I don't see any prohibition on renaming an abstract subprogram. > However, renaming subprograms don't quite take on all the > characteristics of the subprograms they rename; see 8.5.4(12) for > instance. I suspect that has something to do with why renaming an > abstract subprogram could lead to an error, but I don't have time > right this minute to look into it further. > > -- Adam -- -- Stephe