[Mulgara-svn] r810 - branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query

[pag at mulgara.org]

Author: pag
Date: 2008-04-22 10:26:28 -0700 (Tue, 22 Apr 2008)
New Revision: 810

Added:
   branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintIn.java
Log:
A wrapper constraint that evaluates the inner constraint expression according to a set graph, rather than the default graph.

Added: branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintIn.java
===================================================================
--- branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintIn.java	                        (rev 0)
+++ branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintIn.java	2008-04-22 17:26:28 UTC (rev 810)
@@ -0,0 +1,116 @@
+/**
+ * The contents of this file are subject to the Open Software License
+ * Version 3.0 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.opensource.org/licenses/osl-3.0.txt
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ */
+
+package org.mulgara.query;
+
+// Java 2 standard packages
+import java.util.*;
+
+// Third party packages
+// import org.apache.log4j.Logger;
+
+// Local packages
+import org.apache.log4j.Logger;
+
+/**
+ * A constraint expression for setting the GRAPHs of all child expressions.
+ *
+ * @created Apr 22, 2008
+ * @author Paul Gearon
+ * @copyright &copy; 2008 <a href="http://www.topazproject.org/">The Topaz Project</a>
+ * @licence <a href="{@docRoot}/../../LICENCE.txt">Open Software License v3.0</a>
+ */
+public class ConstraintIn implements ConstraintExpression {
+
+  /** Serialization ID for marshalling */
+  private static final long serialVersionUID = 1248304769395263538L;
+
+  /** Logger. */
+  @SuppressWarnings("unused")
+  private final static Logger logger = Logger.getLogger(ConstraintIn.class);
+
+  /** The filtered expression. */
+  private ConstraintExpression constraint;
+
+  /** The IN element to set subconstraints to. */
+  private ConstraintElement graph;
+
+  /**
+   * Construct a filtered constraint.
+   * @param constraint a non-<code>null</code> constraint.
+   * @param graph the value to set all the graphs of all sub-constraints to.
+   * @throws IllegalArgumentException if <var>constraint</var> is <code>null</code>
+   */
+  public ConstraintIn(ConstraintExpression constraint, ConstraintElement graph) {
+    if (constraint == null) throw new IllegalArgumentException("Null \"constraint\" parameter");
+    if (graph == null) throw new IllegalArgumentException("Null graph parameter");
+    this.constraint = constraint;
+    this.graph = graph;
+  }
+  
+  /**
+   * Retrieve the graph to use.
+   * @return the graph value for this constraint.
+   */
+  public ConstraintElement getGraph() {
+    return graph;
+  }
+
+  /**
+   * Gets the constraint being modified by this constraint.
+   * @return The original constraint expression.
+   */
+  public ConstraintExpression getConstraintParam() {
+    return constraint;
+  }
+
+  /** {@inheritDoc} */
+  public ConstraintElement getModel() {
+    return graph;
+  }
+
+
+  /** {@inheritDoc} */
+  public Set<Variable> getVariables() {
+    return constraint.getVariables();
+  }
+
+
+  /** {@inheritDoc} */
+  public boolean isInnerConstraintIs() {
+    return constraint instanceof ConstraintIs;
+  }
+
+  /** {@inheritDoc} */
+  public String toString() {
+    return "GRAPH " + graph + " { " + constraint + " }";
+  }
+
+  /** {@inheritDoc} */
+  public int hashCode() {
+    return constraint.hashCode() * -7;
+  }
+
+  /** {@inheritDoc} */
+  public boolean equals(Object object) {
+    if (object == null) return false;
+    if (object == this) return true;
+
+    // Check that the given object is the correct class.
+    if (!ConstraintIn.class.equals(object.getClass())) return false;
+    // check each element.
+    ConstraintIn other = (ConstraintIn)object;
+    // can't do an equals() on filter, as this evaluates the filter in context
+    return constraint.equals(other.constraint) && graph.equals(other.graph);
+  }
+
+}