add more comments
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/typecomputer/impl/CastListResultTypeComputer.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/typecomputer/impl/CastListResultTypeComputer.java
index d3e0699..4c3c56b 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/typecomputer/impl/CastListResultTypeComputer.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/typecomputer/impl/CastListResultTypeComputer.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
package edu.uci.ics.asterix.om.typecomputer.impl;
import edu.uci.ics.asterix.om.typecomputer.base.IResultTypeComputer;
@@ -9,6 +24,11 @@
import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression;
import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
+/**
+ * The type computer for the cast-list function
+ *
+ * @author yingyib
+ */
public class CastListResultTypeComputer implements IResultTypeComputer {
public static final CastListResultTypeComputer INSTANCE = new CastListResultTypeComputer();
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/CastListDescriptor.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/CastListDescriptor.java
index fb4e2e4..c1817e5 100644
--- a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/CastListDescriptor.java
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/CastListDescriptor.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
package edu.uci.ics.asterix.runtime.evaluators.functions;
import java.io.DataOutput;
@@ -20,6 +35,12 @@
import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
+/**
+ * The runtime function for casting a list(unordered list or ordered list)
+ *
+ * @author yingyib
+ *
+ */
public class CastListDescriptor extends AbstractScalarFunctionDynamicDescriptor {
public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {