Re: About Constructions rules

[Matthias Clasen <clasen@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

> From: "Didier PH Martin" <martind@xxxxxxxxxxxxx>
> Date: Wed, 14 Jul 1999 11:52:20 -0400
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> Hi Peter,
> 
> Peter said:
> But it will only get processed if that node appears in the source grove.
> The query expression is for matching nodes more generally than the other
> expressions, not for inclusion.
> 
> This might be worth noting.
> 
> Didier says:
> I thought a lot about your comment and let's clarify it by sharing our
> thoughts and knowledge about it.
> 
> a) The construction rule firing mechanism is based on a kind of loop. First
> a node is obtained from the source grove. Then the construction rule list is
> enumerated an element at a time for a pattern match. this happens for
> construction rules like: root, element, id, default, query.
> b) if a construction rule list element match the source node, the rule is
> fired and its content-construct executed.
> 
> Do you mean that the query construction rule's query-expression part is
> constrained to be restricted to a current-node query expression. Said
> differently, that the query could only be expressed on the current-node sub
> list or node list elements?
> 

No, I think what Peter wanted to point out is that a query construction 
rule is "fired" for every node of the grove which is a member of the node-list
returned by the query-expression. Your example involving sgml-parse isn't
very useful, since sgml-parse returns a node-list, but none of the nodes is
part of the current grove. Thus the rule will never be fired.

-- 
Matthias Clasen, 
Tel. 0761/203-5606
Email: clasen@xxxxxxxxxxxxxxxxxxxxxxxxxx
Mathematisches Institut, Albert-Ludwigs-Universitaet Freiburg


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