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 Xref: utzoo comp.software-eng:1185 comp.lang.ada:2088 Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!iuvax!purdue!decwrl!megatest!djones From: djones@megatest.UUCP (Dave Jones) Newsgroups: comp.software-eng,comp.lang.ada Subject: Re: Good Design Strategies Message-ID: <2543@goofy.megatest.UUCP> Date: 28 Feb 89 22:35:15 GMT References: <52101@yale-celray.yale.UUCP> Organization: Megatest Corporation, San Jose, Ca List-Id: >From article <52101@yale-celray.yale.UUCP>, by jellinghaus-robert@CS.YALE.EDU (Rob Jellinghaus): > A good object-oriented > system quite often will consist largely of software components that > have been taken from older projects, which is not really a possibility > in either the top-down or the bottom-up model. If the map of a top- > down system is a tree, with the principal function at the top, then > an object-oriented system is a net, with each object providing > services to other objects, with no clear hierarchical arrangement; > this enables the system to be locally modified without global effects. > Point of semantics well taken. Perhaps I should not be using the term "bottom-up". I guess if you get into the topology of it, inheritance of structure (not reference), yields a directed acyclic graph which may have lots of local bottoms and tops. But if I said, "infrenum-supremum" programming, who would know what I was talking about? Dave J.