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: 103376,12a5900a995ed824,start X-Google-Attributes: gid103376,public X-Google-Thread: 114809,e4d2a5e9631f7573 X-Google-Attributes: gid114809,public From: "Mark L. Fussell" Subject: Re: Object Oriented differences between Smalltalk and Ada Date: 1997/10/30 Message-ID: <3458FBA1.152@chimu.com>#1/1 X-Deja-AN: 286879310 References: <34592B6D.226C@ednet.co.uk> To: David Brown X-Trace: 878246852 16831 (none) 206.86.0.12 Organization: ChiMu Corporation Newsgroups: comp.lang.smalltalk,comp.lang.ada Date: 1997-10-30T00:00:00+00:00 List-Id: David Brown wrote: > Can anyone please help me, I have to write an essay on the object > oriented differences between Ada and Smalltalk. Any info. would be > appreciated, even if it was just one one of the languages. That is a hard task: you will really have to immerse yourself in both languages to understand how they think about the world. Although this is always true about language comparisons, Ada and Smalltalk are from to completely different family trees. The following diagram is from: http://www.cs.waikato.ac.nz/~marku/313/oo.history.html Simula | Pascal Smalltalk | . /:\ Modula-2 . / : \ / | \ . / : \ Ada | \ . / : \ / | | \ Self Obj-C C++ Eiffel | Oberon Modula-3 | | | | : | | | | : | Java Sather | Python Cecil Ada95 Although I do not completely agree with the genealogy (some of the references below include alternative diagrams), you can immediately see the problem with comparing Smalltalk and Ada95: Ada95 is "newer" but it was grown from a different root and is growing towards a different sun's light[1,2]. You will need to decide what your goal is. Smalltalk is inherently OO programming. Ada is not. Do you want to compare Ada95's OO features to Smalltalk's OO features? Or do you want to compare some of the goals of OO programming with approaches that can be used in Ada95? The later is a "fairer" comparison because Ada cares about building good software but it does not have the same priorities and approaches as Smalltalk and OO programming. To immerse yourself in the languages you will need books and environments. You can find references to both in the corresponding FAQ's. The following are just samples: Smalltalk-80: The Language and its Implementation. Adele Goldberg and David Robson. Addison-Wesley, Reading, MA, 1983. Squeak http://www.create.ucsb.edu/squeak Ada as a Second Language, Second Edition Norman Cohen. McGraw-Hill, New York, NY, 1996. GNAT http://www.gnat.com/ A few random cross-language resources off my bookshelves: History of Programming Languages-II Thomas Bergin and Richard Gibson, editors. Addison-Wesley, Reading, MA, 1996. Programming Lnaguage Concepts Carlo Ghezzi and Mehdi Jazayeri Wiley, New York, NY, 1987 Computer Languages, A Guide for the Perplexed Naomi Baron Anchor Press/Doubleday, Garden City, NY, 1986. Good luck on your essay and let me know if you find some good online resources. --Mark mark.fussell@chimu.com [1] Java on the other hand has clearly grown from the Smalltalk root although also towards a different SUN. And the unpredictable orbit of that SUN and a bunch of parasitic 'c'ritters have turned Java into a really gnarly branch. [2] Actually, no language has grown much beyond Smalltalk towards the light Alan Kay was reading by. [OK, OK, I am beating up the metaphor. I'll stop now :-]. i ChiMu Corporation Architectures for Information h M info@chimu.com Object-Oriented Information Systems C u www.chimu.com Architecture, Frameworks, and Mentoring