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Re: optional arcs implementation

From: Eric Prud'hommeaux <eric@w3.org>
Date: Fri, 11 Jun 2004 12:09:27 +0900
To: public-rdf-dawg@w3.org, Rob Shearer <Rob.Shearer@networkinference.com>
Message-ID: <20040611030927.GB12275@w3.org>

Added another test case at the bottom (down 100 lines).

On Fri, Jun 11, 2004 at 11:00:07AM +0900, Eric Prud'hommeaux wrote:
> 
> sorry for the delay in sending this out to you:
> 
> The algae code:
> 
> package W3C::Rdf::AlgaeCompileTree::Option;
> sub evaluateQTerm {
>     my ($self, $resultSet, $db, $modifier) = @_;
> 
>     for (my $e = $resultSet->elements; $e->hasMoreElements;) {
> 	my $row = $e->nextElement;
> 	my $miniResultSet = $row->makeResultSet;
> 	$self->{DECL}->evaluateQTerm($miniResultSet, $db, $modifier);
> 	my $empty = 1;
> 	for (my $miniE = $miniResultSet->elements; $miniE->hasMoreElements;) {
> 	    $empty = 0;
> 	    my $miniRow = $miniE->nextElement;
> 	    my $newRow = $row->duplicate;
> 	    $newRow->assumeNewBindings($miniRow);
> 	}
> 	if (!$empty) {
> 	    $row->eliminate;
> 	}
>     }
> }
> 
> The interface to the solution set is:
> for each row
>   for each new solution
>     duplicate the row
>     add the bindings to the new row
> eliminate the original row
> 
> ala:
> sub evaluateQTerm {
>     for (my $e = $resultSet->elements; $e->hasMoreElements;) {
> 	my $row = $e->nextElement;
> 	for each solution
> 	    my $newRow = $row->duplicate;
> 	    $newRow->assumeNewBindings(solution);
> 	}
> 	$row->eliminate;
>     }
> }
> 
> Trivial test:
>   ns <http://example.org/n#>
>   assert (
>    A p1 B .
>    A p2 C .
>    A p3 D .
>   
>    B p1 B .
>    B p2 C )
>   
>   ask (
>    ?n p1 B .
>    ?n p2 C .
>    ~?n p3 ?n2 )
>   
>   collect (?n ?n2)
> got:
> +------------------------+------------------------+
> |                       n|                      n2|
> |------------------------|------------------------|
> |<http://example.org/n#B>|               !unbound!|
> |<http://example.org/n#A>|<http://example.org/n#D>|
> +------------------------+------------------------+
> 
> Testing for unintended extra resuts:
> ns <http://example.org/n#>
>   assert (
>    A p1 B .
>    A p2 C .
>    A p3 D .
>   
>    D p4 E .
>    E p5 F .
>   
>    D2 p4 E2 .
>    E2 p5 F2 )
>   
>   ask (
>    ?n p1 B .
>    ?n p2 C .
>    ~?n ?po ?n2 .
>    ?n2 p4 ?n3 .
>    ?n3 p5 ?n4)
>   
>   collect (?n ?n2 ?po)
> got:
> +------------------------+------------------------+-------------------------+
> |                       n|                      n2|                       po|
> |------------------------|------------------------|-------------------------|
> |<http://example.org/n#A>|<http://example.org/n#D>|<http://example.org/n#p3>|
> +------------------------+------------------------+-------------------------+

Testing nested optionals (comments in the data set demonstrate which
results are expected):

  ns <http://example.org/n#>
  assert (
   A p1 B . # truncates on optional 1 term 1
   A p2 C .
  # A p3 D .
  
  # D p4 E .
  # D p5 F .
  # D p6 F .
  
   A2 p1 B . # truncates on optional term 2
   A2 p2 C .
   A2 p3 D2 .
  
   D2 p4 E2 .
  # D2 p5 F2 .
  # D2 p6 F2 .
  
   A3 p1 B . # eliminates second optional
   A3 p2 C .
   A3 p3 D3 .
  
   D3 p4 E3 .
   D3 p5 F3 .
  # D3 p6 F3 .
  
   A4 p1 B . # has all arcs
   A4 p2 C .
   A4 p3 D4 .
  
   D4 p4 E4 .
   D4 p5 F4 .
   D4 p6 F4 
  )
  
  ask (
   ?n p1 B .
   ?n p2 C .
   ~(?n ?p3 ?d .
     ?d p4 ?e .
     ?d p5 ?f .
     ~?d p6 ?g))
  
  collect (?n ?d ?e ?f ?g)

and this got:
+----------+----------+----------+----------+----------+
|         n|         d|         e|         f|         g|
+----------+----------+----------+----------+----------+
|         A| !unbound!| !unbound!| !unbound!| !unbound!|
|        A2| !unbound!| !unbound!| !unbound!| !unbound!|
|        A3|        D3|        E3|        F3| !unbound!|
|        A4|        D4|        E4|        F4|        F4|
+----------+----------+----------+----------+----------+

-- 
-eric

office: +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA
cell:   +1.857.222.5741

(eric@w3.org)
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Received on Thursday, 10 June 2004 23:09:20 GMT

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