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: 103376,319ef0454c7765d5,start X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 1995-03-24 02:57:27 PST Path: nntp.gmd.de!news.rwth-aachen.de!news.rhrz.uni-bonn.de!news.uni-stuttgart.de!rz.uni-karlsruhe.de!xlink.net!howland.reston.ans.net!cs.utexas.edu!uunet!in1.uu.net!fdn.fr!jussieu.fr!unilim.fr!NewsWatcher!user From: gauthier@unilim.fr (Michel Gauthier) Newsgroups: comp.lang.ada Subject: Re: Why no exception hierarchy ? Date: 24 Mar 1995 11:19:04 GMT Organization: Universite de Limoges Message-ID: References: <3ksv4s$f9e@news.uni-c.dk> NNTP-Posting-Host: 164.81.60.62 Date: 1995-03-24T11:19:04+00:00 List-Id: In article <3ksv4s$f9e@news.uni-c.dk>, mojemj@unidhp.uni-c.dk (Mogens Jensen) wrote: >> [...] >> >> As OOP has been built into the language, class hierarchies/libraries will >> be built (or transferred from C++, maybe?); and these will probably throw >> exceptions. >> As far as I can see, a hierarchy of exceptions would help a lot in such >> a library. >> >> What is the rationale for this (I couldn't find it in either the AARM or >> the Rationale). I cannot answer about the rationale for this, but I can emphasize that something like an exception hierarchy was already implementable in Ada-83, indeed with a lot of genericity (and crashes of the ...X... compiler). Using Ada-95, exception identities are very similar to an 'exception type'. You can pass them as parameters, store them in data structures if suitable (stacks, queues, arrays, record fields). These stored exceptions or parameter exceptions can be raised and handled (using the equality operator). The use of access discriminants to exception identities permits to use an exception as a per-object parameter. All these features are probably sufficient (I have not yet built this exception hierarchy ) to satisfy your needs. So, in fact, is there any real need for more specific features ? -- Michel Gauthier - Laboratoire d'informatique - 123 avenue Albert Thomas F-87060 Limoges - fax +33()55457315 ----- Are the messages that objects exchange also objects ? -----