Adding JMCR-Stable version

[Benchmarks_CSolver.git] / JMCR-Stable / real-world application / MyDerby-10.3 / java / engine / org / apache / derby / impl / sql / compile / SubstituteExpressionVisitor.java

diff --git a/JMCR-Stable/real-world application/MyDerby-10.3/java/engine/org/apache/derby/impl/sql/compile/SubstituteExpressionVisitor.java b/JMCR-Stable/real-world application/MyDerby-10.3/java/engine/org/apache/derby/impl/sql/compile/SubstituteExpressionVisitor.java
new file mode 100644 (file)
index 0000000..b131c98
--- /dev/null
+++ b/JMCR-Stable/real-world application/MyDerby-10.3/java/engine/org/apache/derby/impl/sql/compile/SubstituteExpressionVisitor.java
@@ -0,0 +1,83 @@
+/*\r
+\r
+   Derby - Class org.apache.derby.impl.sql.compile.SubstituteExpressionVisitor\r
+\r
+   Licensed to the Apache Software Foundation (ASF) under one or more\r
+   contributor license agreements.  See the NOTICE file distributed with\r
+   this work for additional information regarding copyright ownership.\r
+   The ASF licenses this file to you under the Apache License, Version 2.0\r
+   (the "License"); you may not use this file except in compliance with\r
+   the License.  You may obtain a copy of the License at\r
+\r
+      http://www.apache.org/licenses/LICENSE-2.0\r
+\r
+   Unless required by applicable law or agreed to in writing, software\r
+   distributed under the License is distributed on an "AS IS" BASIS,\r
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+   See the License for the specific language governing permissions and\r
+   limitations under the License.\r
+\r
+ */\r
+package org.apache.derby.impl.sql.compile;\r
+\r
+import org.apache.derby.iapi.error.StandardException;\r
+import org.apache.derby.iapi.sql.compile.Visitable;\r
+import org.apache.derby.iapi.sql.compile.Visitor;\r
+\r
+/**\r
+ * Replaces a <em>source</em> expression with a <em>target</em>\r
+ * expression.  \r
+ * \r
+ */\r
+class SubstituteExpressionVisitor implements Visitor \r
+{\r
+       private ValueNode source;\r
+       private ValueNode target;\r
+       private Class     skipOverClass;\r
+       \r
+       SubstituteExpressionVisitor(\r
+                       ValueNode s, ValueNode t, Class skipThisClass)  \r
+       {\r
+               source = s;\r
+               target = t;\r
+               skipOverClass = skipThisClass;\r
+       }\r
+\r
+       /**\r
+        * used by GroupByNode to process expressions by complexity level.\r
+        */\r
+       public ValueNode getSource()\r
+       {\r
+               return source;\r
+       }\r
+\r
+       public Visitable visit(Visitable node) throws StandardException \r
+       {\r
+               if (!(node instanceof ValueNode))\r
+               {\r
+                       return node;\r
+               }\r
+               \r
+               ValueNode nd = (ValueNode)node;\r
+               if (nd.isEquivalent(source)) \r
+               {\r
+                       return target;\r
+               } \r
+               else \r
+               {\r
+                       return node;\r
+               }\r
+       }\r
+\r
+       public boolean stopTraversal() \r
+       {\r
+               return false;\r
+       }\r
+\r
+       public boolean skipChildren(Visitable node) \r
+       {\r
+               return (skipOverClass == null) ?\r
+                               false:\r
+                               skipOverClass.isInstance(node);\r
+       }\r
+}\r