[topicmapmail] Topicmaps and LINQ ??

[Lars Marius Garshol]

* Patrick Durusau
>
> I am not real sure what "dreaded so-called impedance mismatch" the  
> author is describing.

Usually programs are written in terms of objects with attributes and  
methods, where many of those objects reflect data that's actually  
stored in a completely different way (as tables with columns and  
rows). Moreover, the language used to deal with objects is completely  
different from that used to deal with the tables.

It's not too unlike having a contract that's written in English,  
following UK legal practice, but where many of the key bits are  
written in Japanese, following Japanese legal practice. I think it's  
quite clear that it would be significantly easier to deal with if it  
was all English or all Japanese. :)

You may want to look at this, btw:
   http://www.garshol.priv.no/download/text/role-of-xml.pdf

Slides 6-17 have a reasonable presentation of this.

> It really looks like they are embedding a query language in a  
> language and then writing converters to make that work with  
> arbitrary back-end database systems and XML.

Yes. I've never written a program like that, but I would think it  
helps somewhat. Data binding (or OR-mapping) seems cleaner to me,  
though.

> Perhaps that reduces the amount of work for programmers and makes  
> it easier to integrate querying in programs since the programmers  
> will have only one interface to learn.
>
> But, and it is a significant *but,* that does not begin to answer  
> the more significant issue which is semantic impedance between  
> systems.

True.

--Lars M.