- Improved (largely) SPARQLLinker rendering, added sameAs equality

html/relnotes.html

@@ -80,8 +80,7 @@ with a warning:
 
 <h2>Version 4.8 (2097): 2015-11-20 - Ant&eacute;sine</h2>
 
-<p>The Alignment API is now compiled in Java 1.8 (it will not compile
-  in 1.7: please provide feedback if you need it in 1.7).</p>
+<p>The Alignment API is now compiled in Java 1.8 (it will not compile in 1.7: please provide feedback if you need it in 1.7).</p>
 
 <p><ul compact="1">
 <li>Fixed a bug in pool aggregation (impl)</li>
@@ -400,11 +399,8 @@ with a warning:
 
 <p><span style="color: red;">BEWARE:</span>
 Java WordNet Library (JWNL) has been upgraded to version 1.4.1rc2 (from 1.3rc3). This is included in the lib directory.
-Hence, it is necessary to use WordNet-3.0 (the jwnl part will not work
-  anymore with 2.0).
-If you want to stay with WordNet-2.0, you need to replace the jwnl.jar
-  library by the older one and this will work. However, using WordNet
-  with the Alignment API is not compulsory.
+Hence, it is necessary to use WordNet-3.0 (the jwnl part will not work anymore with 2.0).
+If you want to stay with WordNet-2.0, you need to replace the jwnl.jar library by the older one and this will work. However, using WordNet with the Alignment API is not compulsory.
 </p>
 <p>
 <ul compact="1">

src/fr/inrialpes/exmo/align/impl/renderer/SPARQLLinkkerRendererVisitor.java

@@ -74,6 +74,8 @@ public class SPARQLLinkkerRendererVisitor extends GraphPatternRendererVisitor im
 
     boolean select = false;
 
+    boolean generateSameAs = false;
+
     boolean requestedblanks = false;
 
     private String content_Corese = "";                     // resulting string for Corese
@@ -101,9 +103,13 @@ public class SPARQLLinkkerRendererVisitor extends GraphPatternRendererVisitor im
         if ( p.getProperty("graphName2") != null ) {
             setGraph2Name( p.getProperty("graphName2") );
         }
-        if ( p.getProperty("select") != null && !p.getProperty("select").equals("") ) {
+        if ( p.getProperty("select") != null ) {
             select = true;
-	} else {
+	}
+        if ( p.getProperty("sameAs") != null ) {
+            generateSameAs = true;
+	}
+	if ( generateSameAs || !select ) {
 	    prefixList.put("http://www.w3.org/2002/07/owl#", "owl");
         }
 
@@ -255,26 +261,48 @@ public class SPARQLLinkkerRendererVisitor extends GraphPatternRendererVisitor im
 
     /**
      * Generate the constraint corresponding to:
-     * MINUS SELECT ?x ?y WHERE { ?x pj ?wj . FILTER NOT EXISTS { ?y qj ?wj . } }
-     * MINUS SELECT ?x ?y WHERE { ?y qj ?wj . FILTER NOT EXISTS { ?x pj ?wj . } }
+     * MINUS { ?x pj ?wj . FILTER NOT EXISTS { ?y qj ?wj . } }
+     * MINUS { ?y qj ?wj . FILTER NOT EXISTS { ?x pj ?wj . } }
+     * Unfortunately with real link keys it should be (for w1 w2 initially selected):
+     * MINUS { ?x pj ?w3 . FILTER ( NOT ( EXISTS { ?y qj ?w4 . } &&  lcase(str(?w3)) = lcase(str(?w4)) )) }
+     * MINUS { ?y qj ?w5 . FILTER ( NOT ( EXISTS { ?x pj ?w6 . } &&  lcase(str(?w6)) = lcase(str(?w5)) )) }
      */
     public void visit( final LinkkeyEquals linkkeyEquals ) throws AlignmentException {
 	// In the semantics of EQ-Linkkeys, the intersection must not be empty...
 	processInLinkKey( linkkeyEquals );
-	initStructure(); //strBGP = ""; // congrats! Unsure
-	String o1 = createVarName();
-	resetVariables( "?s1", o1 );
-	linkkeyEquals.getExpression1().accept( this );
-	String temp = obj;
-        String GP1 = wrapInNamedGraph( onto1NamedGraph, getGP() );
-	initStructure(); //strBGP = ""; // congrats!
-	resetVariables( "?s2", o1 );
-	obj = temp;
-	linkkeyEquals.getExpression2().accept( this );
-        String GP2 = wrapInNamedGraph( onto2NamedGraph, getGP() );
-	lkpattern += "MINUS { " + GP1 + " FILTER NOT EXISTS { " + GP2 + " } }"+NL;
-	lkpattern += "MINUS { " + GP2 + " FILTER NOT EXISTS { " + GP1 + " } }"+NL;
-	// Because virtoso insist on having extravar2 bound in the WHERE clause of the query, we have to add this...
+	if ( (linkkeyEquals.getExpression1() instanceof PropertyExpression) || (linkkeyEquals.getExpression2() instanceof PropertyExpression) ) { // Literal values
+	    //initStructure(); //strBGP = ""; // congrats! Unsure
+	    emptyGP();
+	    String o1 = createVarName();
+	    resetVariables( "?s1", o1 );
+	    linkkeyEquals.getExpression1().accept( this );
+	    String GP1 = wrapInNamedGraph( onto1NamedGraph, getGP() );
+	    //initStructure(); //strBGP = ""; // congrats!
+	    emptyGP();
+	    String o2 = createVarName();
+	    resetVariables( "?s2", o2 );
+	    linkkeyEquals.getExpression2().accept( this );
+	    String GP2 = wrapInNamedGraph( onto2NamedGraph, getGP() );
+	    // The two patterns are independent so can use the same variables
+	    lkpattern += "MINUS { " + GP1 + "FILTER NOT EXISTS { "+ GP2 +" FILTER ( "+equalValueFilterStatement( o1, o2 )+" ) } }"+NL;
+	    lkpattern += "MINUS { " + GP2 + "FILTER NOT EXISTS { "+ GP1 +" FILTER ( "+equalValueFilterStatement( o1, o2 )+" ) } }"+NL;
+	} else if ( generateSameAs ) { // should be the same...
+	} else {
+	    initStructure(); //strBGP = ""; // congrats! Unsure
+	    emptyGP();
+	    String o1 = createVarName();
+	    resetVariables( "?s1", o1 );
+	    linkkeyEquals.getExpression1().accept( this );
+	    String temp = obj;
+	    String GP1 = wrapInNamedGraph( onto1NamedGraph, getGP() );
+	    initStructure(); //strBGP = ""; // congrats!
+	    resetVariables( "?s2", temp );
+	    linkkeyEquals.getExpression2().accept( this );
+	    String GP2 = wrapInNamedGraph( onto2NamedGraph, getGP() );
+	    // The two patterns are independent so can use the same variables
+	    lkpattern += "MINUS { " + GP1 + " FILTER NOT EXISTS { " + GP2 + " } }"+NL;
+	    lkpattern += "MINUS { " + GP2 + " FILTER NOT EXISTS { " + GP1 + " } }"+NL;
+	}
    }
 
     public void visit( final LinkkeyIntersects linkkeyIntersects ) throws AlignmentException {
@@ -294,7 +322,22 @@ public class SPARQLLinkkerRendererVisitor extends GraphPatternRendererVisitor im
 	    resetVariables( lkvar2, o2 );
 	    binding.getExpression2().accept( this );
 	    lkpattern += wrapInNamedGraph( onto2NamedGraph, getGP() );
-	    lkpattern += "FILTER( lcase(str("+o1+")) = lcase(str("+o2+")) )"+NL;
+	    lkpattern += "FILTER ( "+equalValueFilterStatement( o1, o2 )+" )"+NL;
+	    //"FILTER( lcase(str("+o1+")) = lcase(str("+o2+")) )"+NL;
+	} else if ( generateSameAs ) {
+	    // Relations
+	    emptyGP();
+	    String o1 = createVarName();
+	    resetVariables( lkvar1, o1 );
+	    binding.getExpression1().accept( this );
+	    lkpattern += wrapInNamedGraph( onto1NamedGraph, getGP() );
+	    emptyGP();
+	    String o2 = createVarName();
+	    resetVariables( lkvar2, o2 );
+	    binding.getExpression2().accept( this );
+	    lkpattern += wrapInNamedGraph( onto2NamedGraph, getGP() );
+	    lkpattern += "FILTER ( "+equalObjectFilterStatement( o1, o2 )+" )"+NL;
+	    //o1+" owl:sameAs "+o2+"."+NL+" UNION FILTER( "+o1+" = "+o2+" )"+NL;
 	} else {
 	    //?x p'i ?zi . ?y q'i ?zi .
 	    emptyGP();
@@ -309,6 +352,16 @@ public class SPARQLLinkkerRendererVisitor extends GraphPatternRendererVisitor im
 	}
     }
 
+    // There could be two options, test which one is fastest to evaluate...
+    protected String equalObjectFilterStatement ( String o1, String o2 ) {
+	//return o1+" owl:sameAs "+o2+". UNION FILTER( "+o1+" = "+o2+" )";
+	return o1+" = "+o2+" || EXISTS { "+o1+" owl:sameAs "+o2+" . }";
+    }
+    
+    protected String equalValueFilterStatement ( String o1, String o2 ) {
+	return "lcase(str("+o1+")) = lcase(str("+o2+"))";
+    }
+    
     protected String wrapInNamedGraph( String namedGraph, String stuff ) {
         if ( namedGraph != null ) {
             return "GRAPH <" + namedGraph + "> {" + NL + stuff + "}" + NL ;