Add classes for visitor traversal

[cql-java-moved-to-github.git] / src / main / java / org / z3950 / zing / cql / CQLNodeVisitor.java

diff --git a/src/main/java/org/z3950/zing/cql/CQLNodeVisitor.java b/src/main/java/org/z3950/zing/cql/CQLNodeVisitor.java
new file mode 100644 (file)
index 0000000..0d120d8
--- /dev/null
+++ b/src/main/java/org/z3950/zing/cql/CQLNodeVisitor.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 1995-2014, Index Data
+ * All rights reserved.
+ * See the file LICENSE for details.
+ */
+
+package org.z3950.zing.cql;
+
+/**
+ * Allows to visit different types of nodes in the query tree.
+ * @author jakub
+ */
+public interface CQLNodeVisitor {
+  
+  public void onSortNode(CQLSortNode node);
+  
+  public void onPrfixNode(CQLPrefixNode node);
+  
+  public void onBooleanNode(CQLBooleanNode node);
+  
+  public void onProxNode(CQLProxNode node);
+  
+  public void onAndNode(CQLAndNode node);
+  
+  public void onOrNode(CQLOrNode node);
+  
+  public void onNotNode(CQLNotNode node);
+  
+  public void onTermNode(CQLTermNode node);
+  
+  public void onRelation(CQLRelation relation);
+  
+}