[exprla-devel] Re: [XPL] The structure of classes in XPL

[reid_spencer <ras...@re...>]

--- In xpl-dev@y..., "Garreth Galligan" <garreth.galligan@o...> wrote:
When worlds collide, data architecture meets class architecture :)
What's good for data: highly ridged, hierarchical and dependent 
structures
is not necessarily good for a program.

We are certainly staring right into the face of some very big and
interesting contradictions:


Alexander E. Gutman  wrote:

>  As soon as XPL is closely related to XML, the structure
>  of its classes should be as flexible as XML structures.
>  Should we regard classes as XML element types
>  (and, probably, declare them via schema element type definitions)
>  or should we employ a standard approach of some kind?

Just to muddy the waters further - Why Classes at all?
Do Classes truly have any relevance to XML?
Is XML and Classes a square peg in a round hole?
Are we forcing OO paradigms on XML for paradigms' sake?
I don't have the answers, just a lot of questions :)

>  but I wonder if there is a solution close (in flexibility) to that 
of XML

I risk my neck and offer classless (no pun intended) object-based 
languages
(e.g. Self, JavaScript) as an alternative model which perhaps more 
closely
mirror the flexibility and *simplicity* of XML. XML already offers 
many of
the advantages of a class based system, e.g. encapsulation via 
namespaces.

This is probably not the best example in the world to display 
prototyping,
but:

<occupation id="occupation1">
    <title>mathematician</title>
    <workplace>An Institute</workplace>
    <alias>Some Guy</alias>
</occupation>

<occupation id="occupation2">
    <title>programmer</title>
    <workplace>A Company</workplace>
    <alias>Some Guy</alias>
</occupation>


<me>
    <human>
        <name>Alexander Gutman</name>
        <birthdate>1996-07-01</birthdate>
    </human>
    <prototype obj="occupation1">
        <workplace>BlahBlah Institute</workplace>
        <alias>Alex Goodman</alias>
    </prototype>
    <prototype obj="occupation2">
        <alias>Alex Softman</alias>
        <workplace>Foobar Software</workplace>
        <prototype>
            <description>My main job</description>
        </prototype>
    </prototype>
</me>

As you can see with the above we are looking at a much simpler DTD in 
terms
of structural relationships. Defining 'objects' on the simplest level
possible in the DTD and building up relationships in the instance 
document.
--- End forwarded message ---