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=-0.8 required=5.0 tests=BAYES_00,INVALID_DATE autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f891f,bf2f30a0886f0d6c X-Google-Attributes: gidf891f,public X-Google-Thread: 103376,bf2f30a0886f0d6c X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 1993-03-29 02:28:59 PST Xref: sparky comp.lang.ada:4830 comp.lang.misc:4496 Path: sparky!uunet!spool.mu.edu!uwm.edu!caen!batcomputer!ghost.dsi.unimi.it!univ-lyon1.fr!scsing.switch.ch!sicsun!disuns2.epfl.ch!lglsun!nebbe From: nebbe@lglsun.epfl.ch (Robb Nebbe) Newsgroups: comp.lang.ada,comp.lang.misc Subject: Re: Classes vs Tagged Types - Terminology Message-ID: <1993Mar29.104039@lglsun.epfl.ch> Date: 29 Mar 93 09:26:56 GMT References: <1993Mar24.094530@lglsun.epfl.ch> Organization: Ecole Polytechnique Federale de Lausanne NNTP-Posting-Host: lglsun7.epfl.ch Date: 1993-03-29T09:26:56+00:00 List-Id: In article , emery@dr_no.mitre.org (David Emery) writes: : >Tagged types will probably be a peculiarity of Ada (although certainly : >justified in Ada's case) and I don't think we will be seeing other : >languages with tagged types. : > : > Robb : : Modula-3, if I'm not mistaken, uses the same idea as Ada 9X... : dave Modula-3 provides what they call object types but are really just classes in disguise. Modula-3 has adopted a whole new vocabulary but doesn't do anything fundamentally different from all the other "OO" languages such as Smalltalk, Eiffel, Simula, C++, and Objective C. The purpose of the Modula-3 vocabulary seems to be to give the appearance that object types (classes) are well integrated into the type system. This just serves to cover up the fact that Modula-3 is a hybrid language. This is to be contrasted with Ada 9X, where the approach is fundamentally different and the syntax reflects this difference. Ada 9X fully integrates the new OO features with the old OO features. This approach seems to provide quite a few advantages and will certainly be a plus for Ada. The language that comes the closest conceptually to the approach used in Ada 9X is Oberon. Ada 9X is clearly more powerful, but it seems to me that in some cases the solution chosen in Oberon is more appropriate than the solution chosen in Ada 9X; The Ada 9X solution looks a lot like Eiffel in some ways and I'm not sure if it is appropriate or not. Only time will tell. Robb