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, MSGID_SHORT autolearn=no autolearn_force=no version=3.4.4 Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site usl.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!akgub!usl!jih From: jih@usl.UUCP (Juha I. Heinanen) Newsgroups: net.lang.st80,net.lang.ada,net.lang.mod2 Subject: Re: Definition of Buzzwords: "Object-Oriented" Message-ID: <271@usl.UUCP> Date: Tue, 5-Feb-85 11:21:32 EST Article-I.D.: usl.271 Posted: Tue Feb 5 11:21:32 1985 Date-Received: Wed, 6-Feb-85 06:13:15 EST References: <4288@ucbvax.ARPA> <366@cavell.UUCP> <769@loral.UUCP>, <247@cheviot.UUCP> Organization: USL, Lafayette, LA Xref: watmath net.lang.st80:177 net.lang.ada:177 net.lang.mod2:156 List-Id: I agree with Robert Stroud that from the programmer's point of view it was a serious mistake to include the privite part in the package specification and thus force the programmer to tell the memory representation of a private type before writing the package body. Since the algorithms depend on memory representation and vice versa it is in practice impossible to separate the specification from the implementation. This ruins the whole idea of data abstraction with separate compilation. What comes to Modula-2, I wouldn't have placed any restrictions on the memory representation of opaque types. If the actual representation turns out to fit in one word then that is fine. If not I would have made the compiler implicitly declare a pointer variable that points to the real memory representation and implicitly allocate the object from the heap. Similarly all direct references to the memory representation would have been implicitly changed to pointer references. This arrangement would have freed the programmer from the artificial introduction of pointer variables. Juha Heinanen USL, P.O. Box 44330, Lafayette, LA 70504, tel. (318)231-5345 UUCP: {ut-sally, akgua}!usl!jih ARPA: usl!jih@ut-sally -- Will this be appended?