[ONOS-3902, ONOS-3903, ONOS-3904] string type, integer type derrived type

Change-Id: I8279e93fcb7dfb82491cc09057c9d75165add68d
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
index 9c951ae..49c0348 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
@@ -59,15 +59,14 @@
     }
 
     /**
-     * It is called when parser receives an input matching the grammar
-     * rule (config), performs validation and updates the data model
-     * tree.
+     * It is called when parser receives an input matching the grammar rule
+     * (config), performs validation and updates the data model tree.
      *
      * @param listener listener's object.
      * @param ctx context object of the grammar rule.
      */
     public static void processConfigEntry(TreeWalkListener listener,
-                                             GeneratedYangParser.ConfigStatementContext ctx) {
+            GeneratedYangParser.ConfigStatementContext ctx) {
         boolean isConfig = false;
 
         // Check for stack to be non empty.
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java
index 9d41253..d2f90ce 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java
@@ -56,26 +56,27 @@
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.ParsableDataType;
-import static org.onosproject.yangutils.parser.ParsableDataType.TYPEDEF_DATA;
-import static org.onosproject.yangutils.parser.ParsableDataType.UNITS_DATA;
-import static org.onosproject.yangutils.parser.ParsableDataType.DEFAULT_DATA;
-import static org.onosproject.yangutils.parser.ParsableDataType.TYPE_DATA;
-import static org.onosproject.yangutils.parser.ParsableDataType.DESCRIPTION_DATA;
-import static org.onosproject.yangutils.parser.ParsableDataType.REFERENCE_DATA;
-import static org.onosproject.yangutils.parser.ParsableDataType.STATUS_DATA;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.onosproject.yangutils.parser.ParsableDataType.DEFAULT_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.DESCRIPTION_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.REFERENCE_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.STATUS_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.TYPEDEF_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.TYPE_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.UNITS_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_CARDINALITY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 
 /**
@@ -115,8 +116,8 @@
 
         Parsable curData = listener.getParsedDataStack().peek();
 
-        if (curData instanceof YangModule | curData instanceof YangSubModule | curData instanceof YangContainer
-                | curData instanceof YangList) {
+        if ((curData instanceof YangModule) | (curData instanceof YangSubModule) | (curData instanceof YangContainer)
+                | (curData instanceof YangList)) {
             /*
              * TODO YangGrouping, YangRpc, YangInput, YangOutput, Notification.
              */
@@ -150,7 +151,6 @@
         if (listener.getParsedDataStack().peek() instanceof YangTypeDef) {
             listener.getParsedDataStack().pop();
         } else {
-            listener.getErrorInformation().setErrorFlag(true);
             throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, TYPEDEF_DATA,
                     ctx.IDENTIFIER().getText(), EXIT));
         }