From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on ip-172-31-74-118.ec2.internal X-Spam-Level: X-Spam-Status: No, score=0.8 required=3.0 tests=BAYES_50 autolearn=ham autolearn_force=no version=3.4.5-pre1 Date: 14 Apr 93 00:12:48 GMT From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!news.aero.org!jordan@ucb vax.Berkeley.EDU (Larry M. Jordan) Subject: Ichbiah's Letter Message-ID: <1qfku0INN5f9@news.aero.org> List-Id: Omnes: I read Ichbiah's letter to C. Anderson (as I'm sure many of you did). I came away feeling a bit depressed, since I was seriously swayed by the accumulated 'force' of Ichbiah's arguments. I've spent the past few weeks trying to read and comprehend a recent mapping spec (v1.4). I've not addressed any of the tasking related changes. I'm quite familiar with Ada'83, have also taught a C++ course) and I'm struggling with Ada'9X and wondering what herculean effort will be required by the uninitiated C or C++ programmer. I want 9X to not only succeed, I also want it to be an obvious and superior alternative to C++ in my lifetime. I think some of Ichbiah's words 'enjoy' another hearing (I sure relished them): (aesthetics) "More than most people, I am driven by aesthetic considerations and the strong belief that only beautiful shape can be correct shape." "Alltogether, my impression of the present proposal reminds me of my awe when first crossing this bridge in Boston: the Mystic River Bridge. It certainly met the requirements but the accumulation and clutter of metal was oppressive and threatening and ... my preference will always go to the Golden Gate Bridge. The first had engineered features, the second had an Architect and a prodigious Architecture with charm." (homeric allusion, prophesy?!) "(Unlike Cassandra, I speak here with experience. Like Cassandra, however, I may share the dual attributes of being right and not believed.) (upward [in]compatibility) "Success of 9X will not happen unless it is a superset of current Ada: Existing compilers will have to be maintained for their current applications and the resources do not exist to maintain two separate families of compilers." "Moreover, very strict upward compatibility is a prerequisite for the strategy of gradual introduction of 9X features in existing Ada compilers." "With the 9X revision process, we were considering a language revision, as opposed to the design of an entirely new language." (focus) "The priority for OOP comes from a real market requirement - these features will attract new users to Ada - and also from the ability to reuse the significant work that was done in libraries of classes for C++ and Turbo Pascal. So it is part of the effort to interface Ada with the outside world and to reuse software and methods that are developed outside Ada." (complexity) "Moreover, the choice of Ada over some competing language such as C or C++ is not going to depend on the presence of tasking features since these competing alternatives do not have any. On the contrary, the presence in 9X of features that they do not use could be an argument for not using the language as people fear the distributed inefficiencies that are commonplace for implementation of new languages (and with the level of change presently contemplated, 9X would be a new language to which the fine-tuning that took place for Ada in the past ten years would not apply)." (hierarchical libraries) "The feature may be well-designed, but it is nevertheless dead weight. In addition, it has been shown to undermine one of the most valuable conceptual assets of Ada: the safety of packages (with unwanted self-proclaimed children getting access to the private part)." (solution) "I think that the 9X program requires a very substantial reorientation to succeed: I see more risk in continuing in the present course than in attempting a courageous reorientation." I'd like to hear a response from the '9X team to each of these. Or do I ask too much? --Larry "Ted Holden delendus est"