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: 103376,6ff6ac051491e437 X-Google-Attributes: gid103376,public From: dewar@cs.nyu.edu (Robert Dewar) Subject: Re: Question about the need for requeue as described in Rationale Date: 1996/07/04 Message-ID: #1/1 X-Deja-AN: 163822519 references: <31c8fdd4.5a455349@zesi.ruhr.de> <835637893.1349.0@assen.demon.co.uk> <835984668.12569.0@assen.demon.co.uk> <31DAD51F.40F1@csehp3.mdc.com> organization: Courant Institute of Mathematical Sciences newsgroups: comp.lang.ada Date: 1996-07-04T00:00:00+00:00 List-Id: James Squire said ""Indeed, the very astute reader might care to note that we can actually program this example in Ada 95 without using requeue at all." - Great! So why was it used if it wasn't needed? For that matter, how can I do it in Ada 95 without requeue?" That strikes me as a bit odd. You often use features in programming languages that are not "needed", to improve the efficiency, readability, implementability, or simplicity of your code. After all it is obvious that the assignment statement in Ada is redundant in that any code you write using assignments could be written in an applicative style without assignments, but that's no reason to avoid assignments. A complex feature like requeue is never essential from a functionality point of view (though it might be critical on a given implementation from a performance point of view). Clearly anything in Ada 95 that can be written with requeue can be written without, but possibly at the expense of clarity and efficiency. This is one of those situations where the notions of complexity and simplicity get quite confused. Adding a feature like requeue to a language makes he language more complex, but may well make programs using the feature more simple. During the Ada 95 design process, everyone was in favor of simplicity, and opposed to complexity, but we often found that this agreement was pretty meaningless, given these often entirely contradictory ideas of what simplicity might mean. A designer trying to simplify programming in Ada by providing useful new features does *not* find the impelementors agreeing that they are simplifying things :-)