[Mulgara-svn] r768 - branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/filter

[pag at mulgara.org]

Author: pag
Date: 2008-04-10 16:19:58 -0700 (Thu, 10 Apr 2008)
New Revision: 768

Modified:
   branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/filter/TestContext.java
Log:
Added functionality to include nulls as bound objects. These represent unbound values.

Modified: branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/filter/TestContext.java
===================================================================
--- branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/filter/TestContext.java	2008-04-10 23:19:05 UTC (rev 767)
+++ branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/filter/TestContext.java	2008-04-10 23:19:58 UTC (rev 768)
@@ -23,6 +23,7 @@
 
 /**
  * A simple Context used for testing purposes.
+ * This context returns <code>null</code> for unbound values, since it is globalizing.
  * @created Mar 31, 2008
  * @author Paul Gearon
  * @copyright &copy; 2008 <a href="mailto:pgearon at users.sourceforge.net">Paul Gearon</a>
@@ -95,7 +96,7 @@
   public Node globalize(long node) throws QueryException {
     Node n = globalizer.get(node);
     if (n == null) throw new QueryException("Unable to globalize id <" + node + ">");
-    return n;
+    return n != Null.NULL ? n : null;
   }
 
   /** @see org.mulgara.query.filter.Context#isBound(int) */
@@ -114,10 +115,18 @@
     for (Node[] row: rows) {
       assert row.length == columnNames.size();
       for (Node v: row) {
+        if (v == null) v = Null.NULL;
         Node stored = globalizer.get((long)v.hashCode());
         if (stored == null) globalizer.put((long)v.hashCode(), v);
         else assert stored == v : "Unexpected hash collision in test";
       }
     }
   }
+
+  /** Testing class used for storing a symbol for <code>null</code> that is disambiguated from a missing value */
+  @SuppressWarnings("serial")
+  private static class Null implements Node {
+    public static final Null NULL = new Null();
+    public int hashCode() { return -1; }
+  }
 }