Re: [xml-dev] Abstract types in RNG ?

[John Cowan <cowan@mercury.ccil.org>]

David Lee scripsit:

> I'm trying to learn RNG (compact) and I'm stumped on this one.  In XSD
> I can do this but cant figure it out in RNG ... is it possible ?

The key to solving this sort of problem with RNG is to let go of the
idea that you can only name element patterns.  In fact, you can name
any kind of pattern: a sequence of two elements, a choice between three
attributes, a choice between an element and a sequence of two attributes,
all these can have names.  What you need here is to name a sequence,
and you do that like this:

> Address = 
>                 element name { xs:string },
>                 element address1 { xs:string} ,
>                 ...

Note that there are no braces, which are part of the syntax of an
element pattern.

> ShippingAddress  = element shipAddress  { Address }
> 
> BillingAddress  = element billAddress  { Address }
> 
>  
> The only difference between shipAddress and billAddress would be the element
> name.

Just so, since th element patterns have the same named content model.

> Is this possible in RNG ?  I know I can just duplicate the definitions but
> that feels so bad !

It certainly would be.

-- 
Even a refrigerator can conform to the XML      John Cowan
Infoset, as long as it has a door sticker       cowan@ccil.org
saying "No information items inside".           http://www.ccil.org/~cowan
        --Eve Maler