At 06:43 AM 10/2/2001 +1000, Thomas Beale wrote:
>David W Forslund wrote: > >>Thomas Beale writes: >> >> > Do you mean being able to inherit across languages? I thought it was > >> wierd too, but I have seen a demo program in Eiffel... >> > >> >>But why couldn't this be done just as well with Java? Why all of >>sudden with C#? >I suppose no-one has developed the infrastructure to make it work. You >know Sun's ideology: Java or nothing (I'm sure everyone remembers >McNeely's absurd statement that there is no reason to program in anything >but Java.) Sun believes in a monoculture. I know Scott says goofy things, but I don't see what that has to do with having Eiffel work with Java. Java supports CORBA and IIOP, so it obviously is designed to work with other languages. McNealy's statements are far less offensive than those of MS which is even more "monoculture". >> > Two answers: the linux .net (if it exists) allows one flavour of > >> cross-platform; secondly, MSIL is designed to be compiled to binary, >> not > interpreted bytecode like Java, improving performance (presumably >> this > is MSs motive). So you have a back-end cross compiler on every >> platform > for MSIL. >> >>So it is like Corba IDL? Wht is the intermachine protocol? XML? >THere are tools to extract the IDL equivalent, which is I guess a bit more >like an API specification (finer grained than most people would write IDL) >from the MSIL. So if I write an Eiffel.net component, and give it to you >in MSIL, you can write a VB interface to it, based on the interface spec >extractable from the MSIL. How do you hand all the nice things in Eiffel that are not in VB? And doesn't the MSIL have language specific things in it based on your statements below. >>>I don't know all the mechanics, but it at least works with C#, VB, >> > Eiffel and COBOL (of all things). The approach seems to be to define >> a > kind of XXX-#, where XXX is some normal language. The sharp version >> has > to conform to the C# meta-model (no MI, no-variant redefinition, >> no > genericity, etc, type system etc), and then it is a case of >> generating > MSIL from such a compiler. You might say, then you are just >> programming > in C#. But I think the point is that the XXX-# variants >> have the same > syntax as their mother langauges, and can be used in the >> same > development environment. >>But this is not interoperability, as you describe it. Seems like a step >>backwards from current technology. You start with a language and then >>build an inteface from it? >Actually, that's very common. Consider what could happen with say the CEN >or HL7v3 standards. They both include information models (not service >models), describing the required semantics for conformance. If one was to >build a system from them, one could start with UML models, build software, >and export the API via .net. You might say: but why not use HDTF specs. I >say, well you might (should that be "should"?), but some people might not. But aren't you describing language specific interfaces not some higher level UML models? You are saying that the interfaces have language specific things in them, not abstract UML models. What am I missing here? I'm not referring to HDTF specs, here, but trying to understand what it means to generate an interface from a language specific system. This seems to be going from the particular to the general, not the other way around. Dave >- thomas > >
