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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,2ea02452876a15e1 X-Google-Attributes: gid103376,public From: bobduff@world.std.com (Robert A Duff) Subject: Re: Multiple Dispatch in Ada 95 (Was Re: Real OO) Date: 1996/04/21 Message-ID: #1/1 X-Deja-AN: 150628046 references: organization: The World Public Access UNIX, Brookline, MA newsgroups: comp.lang.ada Date: 1996-04-21T00:00:00+00:00 List-Id: In article , Brian Rogoff wrote: >Sure, I've seen the approach. What I was wondering is "What criteria did the >designers of Ada 95 use to decide against supporting multimethods, I thought there was something in the Rationale about it, but I can't seem to find it by quickly flipping through (and the index isn't much help). I think the main reasons were just added complexity (complexity of the language, not so much complexity of the implementation, although that's part of it). With multi-methods, it becomes hard (for the user) to associate a particular method with a particular abstraction -- suppose I want a multi-method that dispatches on two types declared in two different packages -- where do I put it? The same is true of multilple inheritance. I remember discussing it at length with Tucker, and being overwhelmed by the number of extra rules and functionality needed to deal with name clashes and so forth. >...and is >it possible that the issue will be reevaluated in the future?". Anything's possible in Ada 0X. ;-) Also, nothing's stopping somebody from designing a language extension, adding it to GNAT or something, and playing with it to see if it makes sense. - Bob