Re: [service-orientated-architecture] Re: What is a "well defined interface"?

[Ron Schmelzer]

Wow -- very insightful response. That's quite correct. In general, that's why we only have a certain amount of looseness in coupling. You're always coupled at SOME level, and in this case, we have semantic tight coupling, even though we might have delivery loose coupling. So, can you ever truly be "decoupled"? Probably not. But, I love the response - gets to the heart of the matter! Ron Mark Baker wrote: Miko, very cool blog post. You write; > Ok so on to implementation. So we can put this interface up in front of a > pizza hut, or in front of a Domino's pizza or in front of Bilbo's pizza in > Kalamazoo Michigan. Great! Implementation doesnt matter, these are > completely interchangeable, mission accomplished! You could even put this > interface in front of a mail slot, and the money could be immediately grabbed > and the pizza implementation could be outsourced to India. That's great and all, but by only swapping in alternate pizza ordering service implementations in you example, are you then saying that your interface restricts your service implementation that way?  Said another way, could you swap in a sandwich shop, or a shoe shop, or even, say, a filesystem ...?  I think that unless you can, then you haven't truly separated interface from implementation because you've said "No, my implementations can only vary *this* much and no more, because that's all the variation in implementation that my interface permits".  IMO, interface and implementation aren't completely separated until you can answer "yes" to that substitutability question. Mark. -- Mark Baker.  Ottawa, Ontario, CANADA.       http://www.markbaker.ca __________ NOD32 1.1418 (20060224) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com __________ NOD32 1.1418 (20060224) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com -- _____________________________________________________________ Ronald Schmelzer [EMAIL PROTECTED] Senior Analyst ZapThink LLC Direct: 781-577-2779 / Main: 781-207-0203 SPONSORED LINKS Computer software Computer aided design software Computer job Soa Service-oriented architecture YAHOO! GROUPS LINKS  Visit your group "service-orientated-architecture" on the web.    To unsubscribe from this group, send an email to:  [EMAIL PROTECTED]    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.