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I'm using TopBraid Composer Free Edition (TBC FE) Version 5.1.3. I'm building SPIN rules / CONSTRUCT queries. Part of my query has a FILTER statement with multiple OR'd conditions. I enter it into TBC FE as follows:

FILTER (
 (?orgString = SUBSTR("AF  X"^^xsd:string, 1, 4)) ||
 (?orgString = SUBSTR("J   X"^^xsd:string, 1, 4)) || 
 (?orgString = SUBSTR("AR  X"^^xsd:string, 1, 4)) || 
 (?orgString = SUBSTR("N   X"^^xsd:string, 1, 4)) || 
 (?orgString = SUBSTR("NS  X"^^xsd:string, 1, 4)) || 
 (?orgString = SUBSTR("MC  X"^^xsd:string, 1, 4))
) .

But, when I save the SPIN rule in TBC FE, it regroups the OR'd conditions to be a set of binary OR's:

FILTER (
(((((?orgString = SUBSTR("AF  X"^^xsd:string, 1, 4))  || 
    (?orgString = SUBSTR("J   X"^^xsd:string, 1, 4))) ||
    (?orgString = SUBSTR("AR  X"^^xsd:string, 1, 4))) ||
    (?orgString = SUBSTR("N   X"^^xsd:string, 1, 4))) ||
    (?orgString = SUBSTR("NS  X"^^xsd:string, 1, 4))) ||
    (?orgString = SUBSTR("MC  X"^^xsd:string, 1, 4))
) .

My question is: why the regrouping? I've used other SPARQL editors and end points that did not do this regrouping. I contend that this makes my code much harder to read (cost), so I'm wondering what the benefit is?

Also, if this is regrouping is not necessary, is there a way to turn it off in TBC FE?

Thanks.

PS: Yes, I know that taking a substring of a literal string seems stupid. I'm doing it to avoid a bug in Sesame that trims my literal strings when I load my RDF file I save from TBD FE into Sesame. The bug has been reported and is being addressed. When it's fixed, I'll upgrade my Sesame version and remove these ugly substrings.

Stanislav Kralin
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Greg Cox
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1 Answers1

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It's the way Jena print queries, not an aspect of TBC FE. For an binary operator that is left associative the parser creates the expression tree (( E1 op E2 ) op E3 ) and it is printed like that. It is simple and safe; printing expressions does not take precedence into account.

An alternative way to write your FILTER is 

?orgString IN ( SUBSTR("AF  X", 1, 4), SUBSTR("J   X", 1, 4), ...)

in case that is any help.

AndyS
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