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TopQuadrant supports Feature:Assignment

From: Holger Knublauch <holger@topquadrant.com>
Date: Thu, 5 Mar 2009 10:49:44 -0800
Message-Id: <1EECE709-EF2E-4EF6-9BCD-E569D21AA660@topquadrant.com>
To: public-rdf-dawg-comments@w3.org
Dear SPARQL working group,

TopQuadrant (W3C member) strongly supports the proposed Assignment  
feature [1]. In particular we have many customers who rely on the  
ability to construct new RDF nodes (literals and URIs) as part of  
CONSTRUCT rules. Use cases include ontology mapping and deriving new  
values from existing ones. The LET keyword implemented by Jena/ARQ [2]  
has proven to be an excellent solution for those tasks, and leads to  
very readable queries.

Example:

# Computes area := width * height
CONSTRUCT {
     ?this :area ?area .
}
WHERE {
     ?this :width ?width .
     ?this :height ?height .
     LET (?area := (?width * ?height)) .
}

Regards,
Holger

[1] http://www.w3.org/2009/sparql/wiki/Feature:Assignment
[2] Assignment in ARQ
Received on Thursday, 5 March 2009 18:50:29 GMT

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