[Mulgara-svn] r706 - branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query

[pag at mulgara.org]

Author: pag
Date: 2008-03-24 22:12:30 -0700 (Mon, 24 Mar 2008)
New Revision: 706

Added:
   branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintFilter.java
Log:
A new AST object to indicate filtering of a constraint

Added: branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintFilter.java
===================================================================
--- branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintFilter.java	                        (rev 0)
+++ branches/mgr-61-sparql/src/jar/query/java/org/mulgara/query/ConstraintFilter.java	2008-03-25 05:12:30 UTC (rev 706)
@@ -0,0 +1,147 @@
+/*
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (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.mozilla.org/MPL/
+ *
+ * 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.
+ *
+ * The Original Code is the Kowari Metadata Store.
+ *
+ * The Initial Developer of the Original Code is Plugged In Software Pty
+ * Ltd (http://www.pisoftware.com, mailto:info at pisoftware.com). Portions
+ * created by Plugged In Software Pty Ltd are Copyright (C) 2001,2002
+ * Plugged In Software Pty Ltd. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   getModel() contributed by Netymon Pty Ltd on behalf of
+ *   The Australian Commonwealth Government under contract 4500507038.
+ *
+ * [NOTE: The text of this Exhibit A may differ slightly from the text
+ * of the notices in the Source Code files of the Original Code. You
+ * should use the text of this Exhibit A rather than the text found in the
+ * Original Code Source Code for Your Modifications.]
+ *
+ */
+
+package org.mulgara.query;
+
+import java.util.Set;
+
+import org.mulgara.query.filter.Filter;
+
+// Third party packages
+import org.apache.log4j.Logger;
+
+/**
+ * A constraint expression comprised of filtering the subexpression according
+ * to an abstract formula specified as a {@link org.mulgara.query.filter.Filter}.
+ *
+ * @created Mar 24, 2008
+ * @author Paul Gearon
+ * @copyright &copy; 2008 <a href="mailto:pgearon at users.sourceforge.net">Paul Gearon</a>
+ * @licence <a href="{@docRoot}/../../LICENCE.txt">Open Software License v3.0</a>
+ */
+public class ConstraintFilter implements Constraint {
+
+  @SuppressWarnings("unused")
+  /** The logger */
+  private final static Logger logger = Logger.getLogger(ConstraintFilter.class.getName());
+
+  /**
+   * Allow newer compiled version of the stub to operate when changes
+   * have not occurred with the class.
+   * NOTE : update this serialVersionUID when a method or a public member is
+   * deleted.
+   */
+  private static final long serialVersionUID = -816733883358318430L;
+
+  /** The filtered expression. */
+  private Constraint constraint;
+
+  /** The filter construct. */
+  private Filter filter;
+
+  /**
+   * Construct a filtered constraint.
+   * @param constraint a non-<code>null</code> constraint
+   * @throws IllegalArgumentException if <var>constraint</var> is <code>null</code>
+   */
+  public ConstraintFilter(Constraint constraint, Filter filter) {
+    if (constraint == null) throw new IllegalArgumentException("Null \"constraint\" parameter");
+    if (filter == null) throw new IllegalArgumentException("Null \"filter\" parameter");
+    this.constraint = constraint;
+    this.filter = filter;
+  }
+  
+  /**
+   * Retrieve the internal filter expression. This constraint returns data whenever the filter
+   * returns <code>true</code>.
+   * @return the filter for this constraint.
+   */
+  public Filter getFilter() {
+    return filter;
+  }
+
+  /**
+   * Gets the constraint being filtered by this constraint.
+   * @return The original constraint expression.
+   */
+  public Constraint getUnfilteredConstraint() {
+    return constraint;
+  }
+
+  /**
+   * @see org.mulgara.query.Constraint#isRepeating()
+   * Returns the same value as the underlying constraint.
+   */
+  public boolean isRepeating() {
+    return constraint.isRepeating();
+  }
+
+
+  /** {@inheritDoc} */
+  public ConstraintElement getElement(int index) {
+    return constraint.getElement(index);
+  }
+
+  /** {@inheritDoc} */
+  public ConstraintElement getModel() {
+    return constraint.getModel();
+  }
+
+
+  /** {@inheritDoc} */
+  public Set<Variable> getVariables() {
+    return constraint.getVariables();
+  }
+
+
+  /** {@inheritDoc} */
+  public boolean isInnerConstraintIs() {
+    return constraint instanceof ConstraintIs;
+  }
+
+  /** {@inheritDoc} */
+  public String toString() {
+    return "filter " + constraint + " by ";
+  }
+
+  /** {@inheritDoc} */
+  public int hashCode() {
+    return constraint.hashCode() * -1;
+  }
+
+  /** {@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 so check each element.
+    return ConstraintFilter.class.equals(object.getClass()) &&
+           constraint.equals(((ConstraintFilter)object).constraint);
+  }
+}