Re: Redefine?

Nigel Hardy <nwh@aber.ac.uk> writes:

> The listing below sets the (simplified) scene. An element "List"
> contains and number of As and Bs. I'm happy with that schema.
> 
> 
> I then want to create an alternative schema with an additional
> identity constraint, viz. a keyref to ensure that all As reference a
> valid B. For the obvious s/w engineering reasons I would like the
> alternative schema to be based on the original (not copied) so I feel
> I should be using redefine. I can't make this work, feel I am swimming
> against a stream and therefore assume that I have got it all wrong
> somewhere. Can I use redefine to add identity constraints? Should I be
> going about this some other way?

You should be able to, but in fact because keys and keyrefs are part
of element declarations, not type definitions, you can't.  Arguably a
design flaw, sorry.

ht
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Received on Tuesday, 17 June 2003 12:07:38 UTC