Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!tut.cis.ohio-state.edu!unmvax!pprg.unm.edu!hc!lanl!opus!ted From: ted@nmsu.edu (Ted Dunning) Newsgroups: comp.sw.components Subject: Re: Inheritance vs. component efficienc Message-ID: Date: 12 Jun 89 17:49:41 GMT References: <5186@pt.cs.cmu.edu> <5740@hubcap.clemson.edu> Sender: news@nmsu.edu Organization: NMSU Computer Science Lines: 47 In-reply-to: billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu's message of 11 Jun 89 20:26:43 GMT i hate to get a reputation for leaping all over william thomas wolfe's postings (and in fact i actually agreed with most of what he said this time), but.... In article <5740@hubcap.clemson.edu> billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu (William Thomas Wolfe,2847,) writes: ... Why? Ada provides a very high level of support for abstract data types, so no problems there. There is a large and growing set of Ada packages which support specific domains (the classic math libraries are the basis for this increasingly important reuseability strategy), which extend reuseability into reuseable domain-specific knowledge; they certainly work rather effectively. What basis is there for claiming otherwise? there really isn't yet a basis for claiming that there are known problems that need stronger techniques, BUT there are stronger techniques that have been developed that allow much more powerful forms of genericity than that provided in ada (ml is a good early example). these improved forms can actually subsume inheritance and can provide a much simpler interface to a generic package. When we consider that Ada was designed in the late 70's (it took from 1980 to 1983 to get Ada through the ISO), its continuously accelerating popularity almost a decade later is quite remarkable, and a strong affirmation of the vision and skill of its designers. now wait a minute. don't you think that there is a possibility that the interest in ada is mostly market driven? further, isn't there a distinct probability the reason that people are only now beginning to seriously talk about ada is that in spite of the heavy market drive (i.e. dod money), reasonable ada compilers have only recently (last 3 years) become available on machines that people are interested in using? what does it mean if a language is so complex that it takes the resources of the dod nearly 10 years to force the development of even moderate quality compilers for common development platforms? compare this development with the concurrent development of simpler languages that include the important features without including the bureaucratic drek. examples of such languages include modula [23], c++, ml, common lisp and others. compare also the effort required. does 2 or 3 orders of magnitude simpler implementation mean something?