[Mulgara-svn] r964 - trunk/src/jar/resolver-spi/java/org/mulgara/resolver/spi

[pag at mulgara.org]

Author: pag
Date: 2008-05-30 16:58:35 -0700 (Fri, 30 May 2008)
New Revision: 964

Added:
   trunk/src/jar/resolver-spi/java/org/mulgara/resolver/spi/ConstraintVariableRewrite.java
Log:
Added a new mechanism to re-write the names of variables in a constraint. Used for naming duplicate variables, when one of the duplicates is the graph

Added: trunk/src/jar/resolver-spi/java/org/mulgara/resolver/spi/ConstraintVariableRewrite.java
===================================================================
--- trunk/src/jar/resolver-spi/java/org/mulgara/resolver/spi/ConstraintVariableRewrite.java	                        (rev 0)
+++ trunk/src/jar/resolver-spi/java/org/mulgara/resolver/spi/ConstraintVariableRewrite.java	2008-05-30 23:58:35 UTC (rev 964)
@@ -0,0 +1,38 @@
+/*
+ * 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.resolver.spi;
+
+// Local packages
+import org.mulgara.query.Constraint;
+import org.mulgara.query.Variable;
+
+/**
+ * Used to update a given variable in a constraint to a new name.
+ *
+ * @created May 29, 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 interface ConstraintVariableRewrite {
+
+  /**
+   * Rewrite this constraint to use a new variable name
+   *
+   * @param graphVar the graph variable. This will appear elsewhere in the constraint.
+   * @param newVar the new variable to replace the graph variable with outside of the graph position.
+   * @param constraint the constraint to update
+   */
+    public Constraint rewrite(Variable graphVar, Variable newVar, Constraint constraint) throws Exception;
+}