YANG sub module linking + unsupported yang construct + defect fix

Change-Id: I224c8c14ee2111f6844278cb540c48651544f59b

@@ -57,6 +57,11 @@ public class YangBelongsTo implements Parsable {
     private String belongsToModuleName;
     private String belongsToModuleName;
 
 
     /**
     /**
+     * Module node to which sub-module belongs to.
+     */
+    private YangNode moduleNode;
+
+    /**
      * Reference RFC 6020.
      * Reference RFC 6020.
      *
      *
      * The mandatory "prefix" substatement assigns a prefix for the module to
      * The mandatory "prefix" substatement assigns a prefix for the module to
@@ -110,6 +115,24 @@ public class YangBelongsTo implements Parsable {
     }
     }
 
 
     /**
     /**
+     * Returns the module data model node.
+     *
+     * @return the module data model node
+     */
+    public YangNode getModuleNode() {
+        return moduleNode;
+    }
+
+    /**
+     * Sets the module node.
+     *
+     * @param moduleNode module data model node
+     */
+    public void setModuleNode(YangNode moduleNode) {
+        this.moduleNode = moduleNode;
+    }
+
+    /**
      * Returns the type of the data as belongs-to.
      * Returns the type of the data as belongs-to.
      *
      *
      * @return ParsedDataType returns BELONGS_TO_DATA
      * @return ParsedDataType returns BELONGS_TO_DATA

@@ -135,6 +135,12 @@ public class YangChoice extends YangNode
     private YangStatusType status;
     private YangStatusType status;
 
 
     /**
     /**
+     * Default value in string, needs to be converted to the target object,
+     * based on the type.
+     */
+    private String defaultValueInString;
+
+    /**
      * Create a choice node.
      * Create a choice node.
      */
      */
     public YangChoice() {
     public YangChoice() {
@@ -276,6 +282,24 @@ public class YangChoice extends YangNode
     }
     }
 
 
     /**
     /**
+     * Returns the default value.
+     *
+     * @return the default value
+     */
+    public String getDefaultValueInString() {
+        return defaultValueInString;
+    }
+
+    /**
+     * Sets the default value.
+     *
+     * @param defaultValueInString the default value
+     */
+    public void setDefaultValueInString(String defaultValueInString) {
+        this.defaultValueInString = defaultValueInString;
+    }
+
+    /**
      * Returns the type of the data.
      * Returns the type of the data.
      *
      *
      * @return choice data
      * @return choice data

@@ -101,6 +101,12 @@ public class YangLeaf
     private YangType<?> dataType;
     private YangType<?> dataType;
 
 
     /**
     /**
+     * Default value in string, needs to be converted to the target object,
+     * based on the type.
+     */
+    private String defaultValueInString;
+
+    /**
      * Creates a YANG leaf.
      * Creates a YANG leaf.
      */
      */
     public YangLeaf() {
     public YangLeaf() {
@@ -239,6 +245,24 @@ public class YangLeaf
     }
     }
 
 
     /**
     /**
+     * Returns the default value.
+     *
+     * @return the default value
+     */
+    public String getDefaultValueInString() {
+        return defaultValueInString;
+    }
+
+    /**
+     * Sets the default value.
+     *
+     * @param defaultValueInString the default value
+     */
+    public void setDefaultValueInString(String defaultValueInString) {
+        this.defaultValueInString = defaultValueInString;
+    }
+
+    /**
      * Returns the data type.
      * Returns the data type.
      *
      *
      * @return the data type
      * @return the data type

@@ -445,16 +445,10 @@ public class YangList extends YangNode
 
 
         /* A list must have atleast one key leaf if config is true */
         /* A list must have atleast one key leaf if config is true */
         if (isConfig
         if (isConfig
-                && (keys == null || leaves == null && leafLists == null)) {
+                && (keys == null || leaves == null && leafLists == null && !isUsesPresentInList())) {
             throw new DataModelException("A list must have atleast one key leaf if config is true;");
             throw new DataModelException("A list must have atleast one key leaf if config is true;");
         } else if (keys != null) {
         } else if (keys != null) {
-            if (leaves != null) {
-                validateLeafKey(leaves, keys);
-            }
-
-            if (leafLists != null) {
-                validateLeafListKey(leafLists, keys);
-            }
+            validateKey(leaves, leafLists, keys);
         }
         }
     }
     }
 
 
@@ -528,31 +522,51 @@ public class YangList extends YangNode
      * Validates key statement of list.
      * Validates key statement of list.
      *
      *
      * @param leaves list of leaf attributes of list
      * @param leaves list of leaf attributes of list
+     * @param leafLists list of leaf-list attributes of list
      * @param keys list of key attributes of list
      * @param keys list of key attributes of list
      * @throws DataModelException a violation of data model rules
      * @throws DataModelException a violation of data model rules
      */
      */
-    private void validateLeafKey(List<YangLeaf> leaves, List<String> keys) throws DataModelException {
+    private void validateKey(List<YangLeaf> leaves, List<YangLeafList> leafLists, List<String> keys) throws
+            DataModelException {
         boolean leafFound = false;
         boolean leafFound = false;
         List<YangLeaf> keyLeaves = new LinkedList<>();
         List<YangLeaf> keyLeaves = new LinkedList<>();
+        List<YangLeafList> keyLeafLists = new LinkedList<>();
 
 
         /*
         /*
          * 1. Leaf identifier must refer to a child leaf of the list 2. A leaf
          * 1. Leaf identifier must refer to a child leaf of the list 2. A leaf
          * that is part of the key must not be the built-in type "empty".
          * that is part of the key must not be the built-in type "empty".
          */
          */
         for (String key : keys) {
         for (String key : keys) {
-            for (YangLeaf leaf : leaves) {
-                if (key.equals(leaf.getName())) {
-                    if (leaf.getDataType().getDataType() == YangDataTypes.EMPTY) {
-                        throw new DataModelException(" A leaf that is part of the key must not be the built-in " +
-                                "type \"empty\".");
+            if (leaves != null && !leaves.isEmpty()) {
+                for (YangLeaf leaf : leaves) {
+                    if (key.equals(leaf.getName())) {
+                        if (leaf.getDataType().getDataType() == YangDataTypes.EMPTY) {
+                            throw new DataModelException(" A leaf that is part of the key must not be the built-in " +
+                                    "type \"empty\".");
+                        }
+                        leafFound = true;
+                        keyLeaves.add(leaf);
+                        break;
                     }
                     }
-                    leafFound = true;
-                    keyLeaves.add(leaf);
-                    break;
                 }
                 }
             }
             }
-            if (!leafFound) {
-                throw new DataModelException("Leaf identifier must refer to a child leaf of the list");
+
+            if (leafLists != null && !leafLists.isEmpty()) {
+                for (YangLeafList leafList : leafLists) {
+                    if (key.equals(leafList.getName())) {
+                        if (leafList.getDataType().getDataType() == YangDataTypes.EMPTY) {
+                            throw new DataModelException(" A leaf-list that is part of the key" +
+                                    " must not be the built-in type \"empty\".");
+                        }
+                        leafFound = true;
+                        keyLeafLists.add(leafList);
+                        break;
+                    }
+                }
+            }
+
+            if (!leafFound && !isUsesPresentInList()) {
+                throw new DataModelException("An identifier, in key, must refer to a child leaf of the list");
             }
             }
             leafFound = false;
             leafFound = false;
         }
         }
@@ -567,42 +581,8 @@ public class YangList extends YangNode
                         " \"config\" as the list itself.");
                         " \"config\" as the list itself.");
             }
             }
         }
         }
-    }
 
 
-    /**
-     * Validates key statement of list.
-     *
-     * @param leafLists list of leaf-list attributes of list
-     * @param keys list of key attributes of list
-     * @throws DataModelException a violation of data model rules
-     */
-    private void validateLeafListKey(List<YangLeafList> leafLists, List<String> keys) throws DataModelException {
-        boolean leafFound = false;
-        List<YangLeafList> keyLeafLists = new LinkedList<>();
-
-        /*
-         * 1. Leaf identifier must refer to a child leaf of the list 2. A leaf
-         * that is part of the key must not be the built-in type "empty".
-         */
-        for (String key : keys) {
-            for (YangLeafList leafList : leafLists) {
-                if (key.equals(leafList.getName())) {
-                    if (leafList.getDataType().getDataType() == YangDataTypes.EMPTY) {
-                        throw new DataModelException(" A leaf-list that is part of the key must not be the built-in " +
-                                "type \"empty\".");
-                    }
-                    leafFound = true;
-                    keyLeafLists.add(leafList);
-                    break;
-                }
-            }
-            if (!leafFound) {
-                throw new DataModelException("Leaf-list identifier must refer to a child leaf of the list");
-            }
-            leafFound = false;
-        }
-
-        /*
+         /*
          * All key leafs in a list MUST have the same value for their "config"
          * All key leafs in a list MUST have the same value for their "config"
          * as the list itself.
          * as the list itself.
          */
          */
@@ -627,4 +607,16 @@ public class YangList extends YangNode
                     getName() + "\"");
                     getName() + "\"");
         }
         }
     }
     }
+
+    private boolean isUsesPresentInList() {
+        YangNode node = this.getChild();
+        while (node != null) {
+            if (node instanceof YangUses) {
+                return true;
+            }
+            node = node.getNextSibling();
+        }
+        return false;
+    }
+
 }
 }

@@ -19,6 +19,8 @@ package org.onosproject.yangutils.datamodel;
 import java.util.LinkedList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.List;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.utils.YangConstructType;
 import org.onosproject.yangutils.utils.builtindatatype.YangBuiltInDataTypeInfo;
 import org.onosproject.yangutils.utils.builtindatatype.YangBuiltInDataTypeInfo;
 
 
 import static org.onosproject.yangutils.utils.builtindatatype.BuiltInTypeObjectFactory.getDataObjectFromString;
 import static org.onosproject.yangutils.utils.builtindatatype.BuiltInTypeObjectFactory.getDataObjectFromString;
@@ -55,7 +57,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
  * @param <T> range type (data type)
  * @param <T> range type (data type)
  */
  */
 public class YangRangeRestriction<T extends YangBuiltInDataTypeInfo<T>>
 public class YangRangeRestriction<T extends YangBuiltInDataTypeInfo<T>>
-        implements YangDesc, YangReference, YangAppErrorInfo {
+        implements YangDesc, YangReference, YangAppErrorInfo, Parsable {
 
 
     /**
     /**
      * Ascending list of range interval restriction. If the restriction is a
      * Ascending list of range interval restriction. If the restriction is a
@@ -311,4 +313,19 @@ public class YangRangeRestriction<T extends YangBuiltInDataTypeInfo<T>>
     public void setErrorAppTag(String errTag) {
     public void setErrorAppTag(String errTag) {
         errorAppTag = errTag;
         errorAppTag = errTag;
     }
     }
+
+    @Override
+    public YangConstructType getYangConstructType() {
+        return YangConstructType.RANGE_DATA;
+    }
+
+    @Override
+    public void validateDataOnEntry() throws DataModelException {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void validateDataOnExit() throws DataModelException {
+        //TODO: implement the method.
+    }
 }
 }

@@ -16,6 +16,9 @@
 
 
 package org.onosproject.yangutils.datamodel;
 package org.onosproject.yangutils.datamodel;
 
 
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.utils.YangConstructType;
 import org.onosproject.yangutils.utils.builtindatatype.YangUint64;
 import org.onosproject.yangutils.utils.builtindatatype.YangUint64;
 
 
 /*-
 /*-
@@ -28,7 +31,7 @@ import org.onosproject.yangutils.utils.builtindatatype.YangUint64;
 /**
 /**
  * Represents the restriction for string data type.
  * Represents the restriction for string data type.
  */
  */
-public class YangStringRestriction {
+public class YangStringRestriction implements YangDesc, YangReference, YangAppErrorInfo, Parsable {
 
 
     /*-
     /*-
      * Reference RFC 6020.
      * Reference RFC 6020.
@@ -77,6 +80,26 @@ public class YangStringRestriction {
     private YangPatternRestriction patternRestriction;
     private YangPatternRestriction patternRestriction;
 
 
     /**
     /**
+     * Textual reference.
+     */
+    private String reference;
+
+    /**
+     * Application's error message, to be used for data error.
+     */
+    private String errorMessage;
+
+    /**
+     * Application's error tag, to be filled in data validation error response.
+     */
+    private String errorAppTag;
+
+    /**
+     * Textual description.
+     */
+    private String description;
+
+    /**
      * Creates a YANG string restriction object.
      * Creates a YANG string restriction object.
      */
      */
     public YangStringRestriction() {
     public YangStringRestriction() {
@@ -129,4 +152,101 @@ public class YangStringRestriction {
         }
         }
         getPatternRestriction().addPattern(newPattern);
         getPatternRestriction().addPattern(newPattern);
     }
     }
+
+    /**
+     * Returns the textual reference of the string restriction.
+     *
+     * @return textual reference of the string restriction
+     */
+    @Override
+    public String getReference() {
+        return reference;
+    }
+
+    /**
+     * Sets the textual reference of the string restriction.
+     *
+     * @param ref textual reference of the string restriction
+     */
+    @Override
+    public void setReference(String ref) {
+        reference = ref;
+    }
+
+    /**
+     * Returns the description of the string restriction.
+     *
+     * @return description of the string restriction
+     */
+    @Override
+    public String getDescription() {
+        return description;
+    }
+
+    /**
+     * Sets the description of the string restriction.
+     *
+     * @param desc description of the string restriction
+     */
+    @Override
+    public void setDescription(String desc) {
+        description = desc;
+
+    }
+
+    /**
+     * Returns application's error message, to be used for data error.
+     *
+     * @return Application's error message, to be used for data error
+     */
+    @Override
+    public String getGetErrorMessage() {
+        return errorMessage;
+    }
+
+    /**
+     * Sets Application's error message, to be used for data error.
+     *
+     * @param errMsg Application's error message, to be used for data error
+     */
+    @Override
+    public void setErrorMessage(String errMsg) {
+        errorMessage = errMsg;
+
+    }
+
+    /**
+     * Returns application's error tag, to be used for data error.
+     *
+     * @return application's error tag, to be used for data error
+     */
+    @Override
+    public String getGetErrorAppTag() {
+        return errorAppTag;
+    }
+
+    /**
+     * Sets application's error tag, to be used for data error.
+     *
+     * @param errTag application's error tag, to be used for data error.
+     */
+    @Override
+    public void setErrorAppTag(String errTag) {
+        errorAppTag = errTag;
+    }
+
+    @Override
+    public YangConstructType getYangConstructType() {
+        return YangConstructType.PATTERN_DATA;
+    }
+
+    @Override
+    public void validateDataOnEntry() throws DataModelException {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void validateDataOnExit() throws DataModelException {
+        //TODO: implement the method.
+    }
 }
 }

@@ -16,6 +16,7 @@
 
 
 package org.onosproject.yangutils.datamodel.utils;
 package org.onosproject.yangutils.datamodel.utils;
 
 
+import java.util.Iterator;
 import java.util.List;
 import java.util.List;
 
 
 import org.onosproject.yangutils.datamodel.CollisionDetector;
 import org.onosproject.yangutils.datamodel.CollisionDetector;
@@ -29,6 +30,7 @@ import org.onosproject.yangutils.datamodel.YangResolutionInfo;
 import org.onosproject.yangutils.datamodel.YangRpc;
 import org.onosproject.yangutils.datamodel.YangRpc;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.plugin.manager.YangFileInfo;
 import org.onosproject.yangutils.utils.YangConstructType;
 import org.onosproject.yangutils.utils.YangConstructType;
 
 
 /**
 /**
@@ -240,4 +242,26 @@ public final class DataModelUtils {
         }
         }
         return false;
         return false;
     }
     }
+
+    /**
+     * Returns module's data model node to which sub-module belongs to.
+     *
+     * @param yangFileInfo YANG file information
+     * @param belongsToModuleName name of the module to which sub-module belongs to
+     * @return module node to which sub-module belongs to
+     * @throws DataModelException when belongs to module node is not found
+     */
+    public static YangNode findBelongsToModuleNode(List<YangFileInfo> yangFileInfo,
+                String belongsToModuleName) throws DataModelException {
+        Iterator<YangFileInfo> yangFileIterator = yangFileInfo.iterator();
+        while (yangFileIterator.hasNext()) {
+            YangFileInfo yangFile = yangFileIterator.next();
+            YangNode yangNode = yangFile.getRootNode();
+            if (yangNode.getName().equals(belongsToModuleName)) {
+                return yangNode;
+            }
+        }
+        throw new DataModelException("YANG file error : Module " + belongsToModuleName + " to which sub-module " +
+                "belongs to is not found.");
+    }
 }
 }

@@ -75,6 +75,11 @@ import org.onosproject.yangutils.parser.impl.listeners.UnitsListener;
 import org.onosproject.yangutils.parser.impl.listeners.UsesListener;
 import org.onosproject.yangutils.parser.impl.listeners.UsesListener;
 import org.onosproject.yangutils.parser.impl.listeners.ValueListener;
 import org.onosproject.yangutils.parser.impl.listeners.ValueListener;
 import org.onosproject.yangutils.parser.impl.listeners.VersionListener;
 import org.onosproject.yangutils.parser.impl.listeners.VersionListener;
+import org.onosproject.yangutils.utils.YangConstructType;
+
+import static org.onosproject.yangutils.utils.UtilConstants.UNSUPPORTED_YANG_CONSTRUCT;
+import static org.onosproject.yangutils.utils.UtilConstants.CURRENTLY_UNSUPPORTED;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.handleUnsupportedYangConstruct;
 
 
 /**
 /**
  * Represents ANTLR generates parse-tree. ANTLR generates a parse-tree listener interface that responds to events
  * Represents ANTLR generates parse-tree. ANTLR generates a parse-tree listener interface that responds to events
@@ -148,62 +153,62 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterModuleBody(GeneratedYangParser.ModuleBodyContext ctx) {
     public void enterModuleBody(GeneratedYangParser.ModuleBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitModuleBody(GeneratedYangParser.ModuleBodyContext ctx) {
     public void exitModuleBody(GeneratedYangParser.ModuleBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterModuleHeaderStatement(GeneratedYangParser.ModuleHeaderStatementContext ctx) {
     public void enterModuleHeaderStatement(GeneratedYangParser.ModuleHeaderStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitModuleHeaderStatement(GeneratedYangParser.ModuleHeaderStatementContext ctx) {
     public void exitModuleHeaderStatement(GeneratedYangParser.ModuleHeaderStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterLinkageStatements(GeneratedYangParser.LinkageStatementsContext ctx) {
     public void enterLinkageStatements(GeneratedYangParser.LinkageStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitLinkageStatements(GeneratedYangParser.LinkageStatementsContext ctx) {
     public void exitLinkageStatements(GeneratedYangParser.LinkageStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterMetaStatements(GeneratedYangParser.MetaStatementsContext ctx) {
     public void enterMetaStatements(GeneratedYangParser.MetaStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitMetaStatements(GeneratedYangParser.MetaStatementsContext ctx) {
     public void exitMetaStatements(GeneratedYangParser.MetaStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRevisionStatements(GeneratedYangParser.RevisionStatementsContext ctx) {
     public void enterRevisionStatements(GeneratedYangParser.RevisionStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRevisionStatements(GeneratedYangParser.RevisionStatementsContext ctx) {
     public void exitRevisionStatements(GeneratedYangParser.RevisionStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterBodyStatements(GeneratedYangParser.BodyStatementsContext ctx) {
     public void enterBodyStatements(GeneratedYangParser.BodyStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitBodyStatements(GeneratedYangParser.BodyStatementsContext ctx) {
     public void exitBodyStatements(GeneratedYangParser.BodyStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -213,7 +218,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitYangVersionStatement(GeneratedYangParser.YangVersionStatementContext ctx) {
     public void exitYangVersionStatement(GeneratedYangParser.YangVersionStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -223,7 +228,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitNamespaceStatement(GeneratedYangParser.NamespaceStatementContext ctx) {
     public void exitNamespaceStatement(GeneratedYangParser.NamespaceStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -233,7 +238,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitPrefixStatement(GeneratedYangParser.PrefixStatementContext ctx) {
     public void exitPrefixStatement(GeneratedYangParser.PrefixStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -248,12 +253,12 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterImportStatementBody(GeneratedYangParser.ImportStatementBodyContext ctx) {
     public void enterImportStatementBody(GeneratedYangParser.ImportStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitImportStatementBody(GeneratedYangParser.ImportStatementBodyContext ctx) {
     public void exitImportStatementBody(GeneratedYangParser.ImportStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -263,7 +268,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitRevisionDateStatement(GeneratedYangParser.RevisionDateStatementContext ctx) {
     public void exitRevisionDateStatement(GeneratedYangParser.RevisionDateStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -283,7 +288,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitOrganizationStatement(GeneratedYangParser.OrganizationStatementContext ctx) {
     public void exitOrganizationStatement(GeneratedYangParser.OrganizationStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -293,7 +298,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitContactStatement(GeneratedYangParser.ContactStatementContext ctx) {
     public void exitContactStatement(GeneratedYangParser.ContactStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -303,7 +308,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitDescriptionStatement(GeneratedYangParser.DescriptionStatementContext ctx) {
     public void exitDescriptionStatement(GeneratedYangParser.DescriptionStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -313,7 +318,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitReferenceStatement(GeneratedYangParser.ReferenceStatementContext ctx) {
     public void exitReferenceStatement(GeneratedYangParser.ReferenceStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -328,12 +333,12 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterRevisionStatementBody(GeneratedYangParser.RevisionStatementBodyContext ctx) {
     public void enterRevisionStatementBody(GeneratedYangParser.RevisionStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRevisionStatementBody(GeneratedYangParser.RevisionStatementBodyContext ctx) {
     public void exitRevisionStatementBody(GeneratedYangParser.RevisionStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -348,22 +353,22 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterSubmoduleBody(GeneratedYangParser.SubmoduleBodyContext ctx) {
     public void enterSubmoduleBody(GeneratedYangParser.SubmoduleBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitSubmoduleBody(GeneratedYangParser.SubmoduleBodyContext ctx) {
     public void exitSubmoduleBody(GeneratedYangParser.SubmoduleBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterSubmoduleHeaderStatement(GeneratedYangParser.SubmoduleHeaderStatementContext ctx) {
     public void enterSubmoduleHeaderStatement(GeneratedYangParser.SubmoduleHeaderStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitSubmoduleHeaderStatement(GeneratedYangParser.SubmoduleHeaderStatementContext ctx) {
     public void exitSubmoduleHeaderStatement(GeneratedYangParser.SubmoduleHeaderStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -378,132 +383,132 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterBelongstoStatementBody(GeneratedYangParser.BelongstoStatementBodyContext ctx) {
     public void enterBelongstoStatementBody(GeneratedYangParser.BelongstoStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitBelongstoStatementBody(GeneratedYangParser.BelongstoStatementBodyContext ctx) {
     public void exitBelongstoStatementBody(GeneratedYangParser.BelongstoStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterExtensionStatement(GeneratedYangParser.ExtensionStatementContext ctx) {
     public void enterExtensionStatement(GeneratedYangParser.ExtensionStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.EXTENSION_DATA, ctx, UNSUPPORTED_YANG_CONSTRUCT);
     }
     }
 
 
     @Override
     @Override
     public void exitExtensionStatement(GeneratedYangParser.ExtensionStatementContext ctx) {
     public void exitExtensionStatement(GeneratedYangParser.ExtensionStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing
     }
     }
 
 
     @Override
     @Override
     public void enterExtensionBody(GeneratedYangParser.ExtensionBodyContext ctx) {
     public void enterExtensionBody(GeneratedYangParser.ExtensionBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitExtensionBody(GeneratedYangParser.ExtensionBodyContext ctx) {
     public void exitExtensionBody(GeneratedYangParser.ExtensionBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterArgumentStatement(GeneratedYangParser.ArgumentStatementContext ctx) {
     public void enterArgumentStatement(GeneratedYangParser.ArgumentStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitArgumentStatement(GeneratedYangParser.ArgumentStatementContext ctx) {
     public void exitArgumentStatement(GeneratedYangParser.ArgumentStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterArgumentBody(GeneratedYangParser.ArgumentBodyContext ctx) {
     public void enterArgumentBody(GeneratedYangParser.ArgumentBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitArgumentBody(GeneratedYangParser.ArgumentBodyContext ctx) {
     public void exitArgumentBody(GeneratedYangParser.ArgumentBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterYinElementStatement(GeneratedYangParser.YinElementStatementContext ctx) {
     public void enterYinElementStatement(GeneratedYangParser.YinElementStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitYinElementStatement(GeneratedYangParser.YinElementStatementContext ctx) {
     public void exitYinElementStatement(GeneratedYangParser.YinElementStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterIdentityStatement(GeneratedYangParser.IdentityStatementContext ctx) {
     public void enterIdentityStatement(GeneratedYangParser.IdentityStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.IDENTITY_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitIdentityStatement(GeneratedYangParser.IdentityStatementContext ctx) {
     public void exitIdentityStatement(GeneratedYangParser.IdentityStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterIdentityBody(GeneratedYangParser.IdentityBodyContext ctx) {
     public void enterIdentityBody(GeneratedYangParser.IdentityBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitIdentityBody(GeneratedYangParser.IdentityBodyContext ctx) {
     public void exitIdentityBody(GeneratedYangParser.IdentityBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterBaseStatement(GeneratedYangParser.BaseStatementContext ctx) {
     public void enterBaseStatement(GeneratedYangParser.BaseStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.BASE_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitBaseStatement(GeneratedYangParser.BaseStatementContext ctx) {
     public void exitBaseStatement(GeneratedYangParser.BaseStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterFeatureStatement(GeneratedYangParser.FeatureStatementContext ctx) {
     public void enterFeatureStatement(GeneratedYangParser.FeatureStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.FEATURE_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitFeatureStatement(GeneratedYangParser.FeatureStatementContext ctx) {
     public void exitFeatureStatement(GeneratedYangParser.FeatureStatementContext ctx) {
-        // TODO: implement the method.
+        //TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
     public void enterFeatureBody(GeneratedYangParser.FeatureBodyContext ctx) {
     public void enterFeatureBody(GeneratedYangParser.FeatureBodyContext ctx) {
-        // TODO: implement the method.
+        //TODO : to be implemented
     }
     }
 
 
     @Override
     @Override
     public void exitFeatureBody(GeneratedYangParser.FeatureBodyContext ctx) {
     public void exitFeatureBody(GeneratedYangParser.FeatureBodyContext ctx) {
-        // TODO: implement the method.
+        //TODO : to be implemented
     }
     }
 
 
     @Override
     @Override
     public void enterDataDefStatement(GeneratedYangParser.DataDefStatementContext ctx) {
     public void enterDataDefStatement(GeneratedYangParser.DataDefStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDataDefStatement(GeneratedYangParser.DataDefStatementContext ctx) {
     public void exitDataDefStatement(GeneratedYangParser.DataDefStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterIfFeatureStatement(GeneratedYangParser.IfFeatureStatementContext ctx) {
     public void enterIfFeatureStatement(GeneratedYangParser.IfFeatureStatementContext ctx) {
-        // TODO: implement the method.
+        // TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
     public void exitIfFeatureStatement(GeneratedYangParser.IfFeatureStatementContext ctx) {
     public void exitIfFeatureStatement(GeneratedYangParser.IfFeatureStatementContext ctx) {
-        // TODO: implement the method.
+        // TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
@@ -513,7 +518,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitUnitsStatement(GeneratedYangParser.UnitsStatementContext ctx) {
     public void exitUnitsStatement(GeneratedYangParser.UnitsStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -538,22 +543,32 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterTypeBodyStatements(GeneratedYangParser.TypeBodyStatementsContext ctx) {
     public void enterTypeBodyStatements(GeneratedYangParser.TypeBodyStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitTypeBodyStatements(GeneratedYangParser.TypeBodyStatementsContext ctx) {
     public void exitTypeBodyStatements(GeneratedYangParser.TypeBodyStatementsContext ctx) {
+        // do nothing.
+    }
+
+    @Override
+    public void enterDecimal64Specification(GeneratedYangParser.Decimal64SpecificationContext ctx) {
         // TODO: implement the method.
         // TODO: implement the method.
     }
     }
 
 
     @Override
     @Override
-    public void enterNumericalRestrictions(GeneratedYangParser.NumericalRestrictionsContext ctx) {
+    public void exitDecimal64Specification(GeneratedYangParser.Decimal64SpecificationContext ctx) {
         // TODO: implement the method.
         // TODO: implement the method.
     }
     }
 
 
     @Override
     @Override
+    public void enterNumericalRestrictions(GeneratedYangParser.NumericalRestrictionsContext ctx) {
+        // do nothing.
+    }
+
+    @Override
     public void exitNumericalRestrictions(GeneratedYangParser.NumericalRestrictionsContext ctx) {
     public void exitNumericalRestrictions(GeneratedYangParser.NumericalRestrictionsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -563,27 +578,27 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitRangeStatement(GeneratedYangParser.RangeStatementContext ctx) {
     public void exitRangeStatement(GeneratedYangParser.RangeStatementContext ctx) {
-        // TODO: implement the method.
+        RangeRestrictionListener.processRangeRestrictionExit(this, ctx);
     }
     }
 
 
     @Override
     @Override
     public void enterCommonStatements(GeneratedYangParser.CommonStatementsContext ctx) {
     public void enterCommonStatements(GeneratedYangParser.CommonStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitCommonStatements(GeneratedYangParser.CommonStatementsContext ctx) {
     public void exitCommonStatements(GeneratedYangParser.CommonStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterStringRestrictions(GeneratedYangParser.StringRestrictionsContext ctx) {
     public void enterStringRestrictions(GeneratedYangParser.StringRestrictionsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitStringRestrictions(GeneratedYangParser.StringRestrictionsContext ctx) {
     public void exitStringRestrictions(GeneratedYangParser.StringRestrictionsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -593,7 +608,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitLengthStatement(GeneratedYangParser.LengthStatementContext ctx) {
     public void exitLengthStatement(GeneratedYangParser.LengthStatementContext ctx) {
-        // TODO: implement the method.
+        LengthRestrictionListener.processLengthRestrictionExit(this, ctx);
     }
     }
 
 
     @Override
     @Override
@@ -603,7 +618,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitPatternStatement(GeneratedYangParser.PatternStatementContext ctx) {
     public void exitPatternStatement(GeneratedYangParser.PatternStatementContext ctx) {
-        // TODO: implement the method.
+        PatternRestrictionListener.processPatternRestrictionExit(this, ctx);
     }
     }
 
 
     @Override
     @Override
@@ -613,7 +628,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitDefaultStatement(GeneratedYangParser.DefaultStatementContext ctx) {
     public void exitDefaultStatement(GeneratedYangParser.DefaultStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -638,62 +653,62 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterEnumStatementBody(GeneratedYangParser.EnumStatementBodyContext ctx) {
     public void enterEnumStatementBody(GeneratedYangParser.EnumStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitEnumStatementBody(GeneratedYangParser.EnumStatementBodyContext ctx) {
     public void exitEnumStatementBody(GeneratedYangParser.EnumStatementBodyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterLeafrefSpecification(GeneratedYangParser.LeafrefSpecificationContext ctx) {
     public void enterLeafrefSpecification(GeneratedYangParser.LeafrefSpecificationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitLeafrefSpecification(GeneratedYangParser.LeafrefSpecificationContext ctx) {
     public void exitLeafrefSpecification(GeneratedYangParser.LeafrefSpecificationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterPathStatement(GeneratedYangParser.PathStatementContext ctx) {
     public void enterPathStatement(GeneratedYangParser.PathStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.PATH_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitPathStatement(GeneratedYangParser.PathStatementContext ctx) {
     public void exitPathStatement(GeneratedYangParser.PathStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRequireInstanceStatement(GeneratedYangParser.RequireInstanceStatementContext ctx) {
     public void enterRequireInstanceStatement(GeneratedYangParser.RequireInstanceStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.REQUIRE_INSTANCE_DATA, ctx, UNSUPPORTED_YANG_CONSTRUCT);
     }
     }
 
 
     @Override
     @Override
     public void exitRequireInstanceStatement(GeneratedYangParser.RequireInstanceStatementContext ctx) {
     public void exitRequireInstanceStatement(GeneratedYangParser.RequireInstanceStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterInstanceIdentifierSpecification(GeneratedYangParser.InstanceIdentifierSpecificationContext ctx) {
     public void enterInstanceIdentifierSpecification(GeneratedYangParser.InstanceIdentifierSpecificationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitInstanceIdentifierSpecification(GeneratedYangParser.InstanceIdentifierSpecificationContext ctx) {
     public void exitInstanceIdentifierSpecification(GeneratedYangParser.InstanceIdentifierSpecificationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterIdentityrefSpecification(GeneratedYangParser.IdentityrefSpecificationContext ctx) {
     public void enterIdentityrefSpecification(GeneratedYangParser.IdentityrefSpecificationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitIdentityrefSpecification(GeneratedYangParser.IdentityrefSpecificationContext ctx) {
     public void exitIdentityrefSpecification(GeneratedYangParser.IdentityrefSpecificationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -728,12 +743,12 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterBitBodyStatement(GeneratedYangParser.BitBodyStatementContext ctx) {
     public void enterBitBodyStatement(GeneratedYangParser.BitBodyStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitBitBodyStatement(GeneratedYangParser.BitBodyStatementContext ctx) {
     public void exitBitBodyStatement(GeneratedYangParser.BitBodyStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -743,7 +758,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitPositionStatement(GeneratedYangParser.PositionStatementContext ctx) {
     public void exitPositionStatement(GeneratedYangParser.PositionStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -753,7 +768,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitStatusStatement(GeneratedYangParser.StatusStatementContext ctx) {
     public void exitStatusStatement(GeneratedYangParser.StatusStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -763,7 +778,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitConfigStatement(GeneratedYangParser.ConfigStatementContext ctx) {
     public void exitConfigStatement(GeneratedYangParser.ConfigStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -773,7 +788,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitMandatoryStatement(GeneratedYangParser.MandatoryStatementContext ctx) {
     public void exitMandatoryStatement(GeneratedYangParser.MandatoryStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -783,47 +798,47 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitPresenceStatement(GeneratedYangParser.PresenceStatementContext ctx) {
     public void exitPresenceStatement(GeneratedYangParser.PresenceStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterOrderedByStatement(GeneratedYangParser.OrderedByStatementContext ctx) {
     public void enterOrderedByStatement(GeneratedYangParser.OrderedByStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.ORDERED_BY_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitOrderedByStatement(GeneratedYangParser.OrderedByStatementContext ctx) {
     public void exitOrderedByStatement(GeneratedYangParser.OrderedByStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterMustStatement(GeneratedYangParser.MustStatementContext ctx) {
     public void enterMustStatement(GeneratedYangParser.MustStatementContext ctx) {
-        // TODO: implement the method.
+        // TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
     public void exitMustStatement(GeneratedYangParser.MustStatementContext ctx) {
     public void exitMustStatement(GeneratedYangParser.MustStatementContext ctx) {
-        // TODO: implement the method.
+        // TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
     public void enterErrorMessageStatement(GeneratedYangParser.ErrorMessageStatementContext ctx) {
     public void enterErrorMessageStatement(GeneratedYangParser.ErrorMessageStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.ERROR_MESSAGE_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitErrorMessageStatement(GeneratedYangParser.ErrorMessageStatementContext ctx) {
     public void exitErrorMessageStatement(GeneratedYangParser.ErrorMessageStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterErrorAppTagStatement(GeneratedYangParser.ErrorAppTagStatementContext ctx) {
     public void enterErrorAppTagStatement(GeneratedYangParser.ErrorAppTagStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.ERROR_APP_TAG_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitErrorAppTagStatement(GeneratedYangParser.ErrorAppTagStatementContext ctx) {
     public void exitErrorAppTagStatement(GeneratedYangParser.ErrorAppTagStatementContext ctx) {
-        // TODO: implement the method.
+        //do nothing
     }
     }
 
 
     @Override
     @Override
@@ -833,7 +848,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitMinElementsStatement(GeneratedYangParser.MinElementsStatementContext ctx) {
     public void exitMinElementsStatement(GeneratedYangParser.MinElementsStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -843,7 +858,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitMaxElementsStatement(GeneratedYangParser.MaxElementsStatementContext ctx) {
     public void exitMaxElementsStatement(GeneratedYangParser.MaxElementsStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -853,7 +868,7 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitValueStatement(GeneratedYangParser.ValueStatementContext ctx) {
     public void exitValueStatement(GeneratedYangParser.ValueStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -913,17 +928,17 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void exitKeyStatement(GeneratedYangParser.KeyStatementContext ctx) {
     public void exitKeyStatement(GeneratedYangParser.KeyStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterUniqueStatement(GeneratedYangParser.UniqueStatementContext ctx) {
     public void enterUniqueStatement(GeneratedYangParser.UniqueStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.UNIQUE_DATA, ctx, CURRENTLY_UNSUPPORTED);
     }
     }
 
 
     @Override
     @Override
     public void exitUniqueStatement(GeneratedYangParser.UniqueStatementContext ctx) {
     public void exitUniqueStatement(GeneratedYangParser.UniqueStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -957,6 +972,16 @@ public class TreeWalkListener implements GeneratedYangListener {
     }
     }
 
 
     @Override
     @Override
+    public void enterAnyxmlStatement(GeneratedYangParser.AnyxmlStatementContext ctx) {
+        handleUnsupportedYangConstruct(YangConstructType.ANYXML_DATA, ctx, UNSUPPORTED_YANG_CONSTRUCT);
+    }
+
+    @Override
+    public void exitAnyxmlStatement(GeneratedYangParser.AnyxmlStatementContext ctx) {
+        // do nothing.
+    }
+
+    @Override
     public void enterUsesStatement(GeneratedYangParser.UsesStatementContext ctx) {
     public void enterUsesStatement(GeneratedYangParser.UsesStatementContext ctx) {
         UsesListener.processUsesEntry(this, ctx);
         UsesListener.processUsesEntry(this, ctx);
     }
     }
@@ -968,82 +993,82 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterRefineStatement(GeneratedYangParser.RefineStatementContext ctx) {
     public void enterRefineStatement(GeneratedYangParser.RefineStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.REFINE_DATA, ctx, UNSUPPORTED_YANG_CONSTRUCT);
     }
     }
 
 
     @Override
     @Override
     public void exitRefineStatement(GeneratedYangParser.RefineStatementContext ctx) {
     public void exitRefineStatement(GeneratedYangParser.RefineStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefineContainerStatements(GeneratedYangParser.RefineContainerStatementsContext ctx) {
     public void enterRefineContainerStatements(GeneratedYangParser.RefineContainerStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefineContainerStatements(GeneratedYangParser.RefineContainerStatementsContext ctx) {
     public void exitRefineContainerStatements(GeneratedYangParser.RefineContainerStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefineLeafStatements(GeneratedYangParser.RefineLeafStatementsContext ctx) {
     public void enterRefineLeafStatements(GeneratedYangParser.RefineLeafStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefineLeafStatements(GeneratedYangParser.RefineLeafStatementsContext ctx) {
     public void exitRefineLeafStatements(GeneratedYangParser.RefineLeafStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefineLeafListStatements(GeneratedYangParser.RefineLeafListStatementsContext ctx) {
     public void enterRefineLeafListStatements(GeneratedYangParser.RefineLeafListStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefineLeafListStatements(GeneratedYangParser.RefineLeafListStatementsContext ctx) {
     public void exitRefineLeafListStatements(GeneratedYangParser.RefineLeafListStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefineListStatements(GeneratedYangParser.RefineListStatementsContext ctx) {
     public void enterRefineListStatements(GeneratedYangParser.RefineListStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefineListStatements(GeneratedYangParser.RefineListStatementsContext ctx) {
     public void exitRefineListStatements(GeneratedYangParser.RefineListStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefineChoiceStatements(GeneratedYangParser.RefineChoiceStatementsContext ctx) {
     public void enterRefineChoiceStatements(GeneratedYangParser.RefineChoiceStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefineChoiceStatements(GeneratedYangParser.RefineChoiceStatementsContext ctx) {
     public void exitRefineChoiceStatements(GeneratedYangParser.RefineChoiceStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefineCaseStatements(GeneratedYangParser.RefineCaseStatementsContext ctx) {
     public void enterRefineCaseStatements(GeneratedYangParser.RefineCaseStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefineCaseStatements(GeneratedYangParser.RefineCaseStatementsContext ctx) {
     public void exitRefineCaseStatements(GeneratedYangParser.RefineCaseStatementsContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
-    public void enterUsesAugmentStatement(GeneratedYangParser.UsesAugmentStatementContext ctx) {
-        // TODO: implement the method.
+    public void enterRefineAnyxmlStatements(GeneratedYangParser.RefineAnyxmlStatementsContext ctx) {
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
-    public void exitUsesAugmentStatement(GeneratedYangParser.UsesAugmentStatementContext ctx) {
-        // TODO: implement the method.
+    public void exitRefineAnyxmlStatements(GeneratedYangParser.RefineAnyxmlStatementsContext ctx) {
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
@@ -1058,12 +1083,12 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterWhenStatement(GeneratedYangParser.WhenStatementContext ctx) {
     public void enterWhenStatement(GeneratedYangParser.WhenStatementContext ctx) {
-        // TODO: implement the method.
+        // TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
     public void exitWhenStatement(GeneratedYangParser.WhenStatementContext ctx) {
     public void exitWhenStatement(GeneratedYangParser.WhenStatementContext ctx) {
-        // TODO: implement the method.
+        // TODO: to be implemented
     }
     }
 
 
     @Override
     @Override
@@ -1108,271 +1133,291 @@ public class TreeWalkListener implements GeneratedYangListener {
 
 
     @Override
     @Override
     public void enterDeviationStatement(GeneratedYangParser.DeviationStatementContext ctx) {
     public void enterDeviationStatement(GeneratedYangParser.DeviationStatementContext ctx) {
-        // TODO: implement the method.
+        handleUnsupportedYangConstruct(YangConstructType.DEVIATION_DATA, ctx, UNSUPPORTED_YANG_CONSTRUCT);
     }
     }
 
 
     @Override
     @Override
     public void exitDeviationStatement(GeneratedYangParser.DeviationStatementContext ctx) {
     public void exitDeviationStatement(GeneratedYangParser.DeviationStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterDeviateNotSupportedStatement(GeneratedYangParser.DeviateNotSupportedStatementContext ctx) {
     public void enterDeviateNotSupportedStatement(GeneratedYangParser.DeviateNotSupportedStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDeviateNotSupportedStatement(GeneratedYangParser.DeviateNotSupportedStatementContext ctx) {
     public void exitDeviateNotSupportedStatement(GeneratedYangParser.DeviateNotSupportedStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterDeviateAddStatement(GeneratedYangParser.DeviateAddStatementContext ctx) {
     public void enterDeviateAddStatement(GeneratedYangParser.DeviateAddStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDeviateAddStatement(GeneratedYangParser.DeviateAddStatementContext ctx) {
     public void exitDeviateAddStatement(GeneratedYangParser.DeviateAddStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterDeviateDeleteStatement(GeneratedYangParser.DeviateDeleteStatementContext ctx) {
     public void enterDeviateDeleteStatement(GeneratedYangParser.DeviateDeleteStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDeviateDeleteStatement(GeneratedYangParser.DeviateDeleteStatementContext ctx) {
     public void exitDeviateDeleteStatement(GeneratedYangParser.DeviateDeleteStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterDeviateReplaceStatement(GeneratedYangParser.DeviateReplaceStatementContext ctx) {
     public void enterDeviateReplaceStatement(GeneratedYangParser.DeviateReplaceStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDeviateReplaceStatement(GeneratedYangParser.DeviateReplaceStatementContext ctx) {
     public void exitDeviateReplaceStatement(GeneratedYangParser.DeviateReplaceStatementContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterString(GeneratedYangParser.StringContext ctx) {
     public void enterString(GeneratedYangParser.StringContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitString(GeneratedYangParser.StringContext ctx) {
     public void exitString(GeneratedYangParser.StringContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterIdentifier(GeneratedYangParser.IdentifierContext ctx) {
     public void enterIdentifier(GeneratedYangParser.IdentifierContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitIdentifier(GeneratedYangParser.IdentifierContext ctx) {
     public void exitIdentifier(GeneratedYangParser.IdentifierContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterDateArgumentString(GeneratedYangParser.DateArgumentStringContext ctx) {
     public void enterDateArgumentString(GeneratedYangParser.DateArgumentStringContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDateArgumentString(GeneratedYangParser.DateArgumentStringContext ctx) {
     public void exitDateArgumentString(GeneratedYangParser.DateArgumentStringContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRange(GeneratedYangParser.RangeContext ctx) {
     public void enterRange(GeneratedYangParser.RangeContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRange(GeneratedYangParser.RangeContext ctx) {
     public void exitRange(GeneratedYangParser.RangeContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterLength(GeneratedYangParser.LengthContext ctx) {
     public void enterLength(GeneratedYangParser.LengthContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitLength(GeneratedYangParser.LengthContext ctx) {
     public void exitLength(GeneratedYangParser.LengthContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterPath(GeneratedYangParser.PathContext ctx) {
     public void enterPath(GeneratedYangParser.PathContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitPath(GeneratedYangParser.PathContext ctx) {
     public void exitPath(GeneratedYangParser.PathContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterPosition(GeneratedYangParser.PositionContext ctx) {
     public void enterPosition(GeneratedYangParser.PositionContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitPosition(GeneratedYangParser.PositionContext ctx) {
     public void exitPosition(GeneratedYangParser.PositionContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterStatus(GeneratedYangParser.StatusContext ctx) {
     public void enterStatus(GeneratedYangParser.StatusContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitStatus(GeneratedYangParser.StatusContext ctx) {
     public void exitStatus(GeneratedYangParser.StatusContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterConfig(GeneratedYangParser.ConfigContext ctx) {
     public void enterConfig(GeneratedYangParser.ConfigContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitConfig(GeneratedYangParser.ConfigContext ctx) {
     public void exitConfig(GeneratedYangParser.ConfigContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterMandatory(GeneratedYangParser.MandatoryContext ctx) {
     public void enterMandatory(GeneratedYangParser.MandatoryContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitMandatory(GeneratedYangParser.MandatoryContext ctx) {
     public void exitMandatory(GeneratedYangParser.MandatoryContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterOrderedBy(GeneratedYangParser.OrderedByContext ctx) {
     public void enterOrderedBy(GeneratedYangParser.OrderedByContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitOrderedBy(GeneratedYangParser.OrderedByContext ctx) {
     public void exitOrderedBy(GeneratedYangParser.OrderedByContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterMinValue(GeneratedYangParser.MinValueContext ctx) {
     public void enterMinValue(GeneratedYangParser.MinValueContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitMinValue(GeneratedYangParser.MinValueContext ctx) {
     public void exitMinValue(GeneratedYangParser.MinValueContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterMaxValue(GeneratedYangParser.MaxValueContext ctx) {
     public void enterMaxValue(GeneratedYangParser.MaxValueContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitMaxValue(GeneratedYangParser.MaxValueContext ctx) {
     public void exitMaxValue(GeneratedYangParser.MaxValueContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterKey(GeneratedYangParser.KeyContext ctx) {
     public void enterKey(GeneratedYangParser.KeyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitKey(GeneratedYangParser.KeyContext ctx) {
     public void exitKey(GeneratedYangParser.KeyContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterUnique(GeneratedYangParser.UniqueContext ctx) {
     public void enterUnique(GeneratedYangParser.UniqueContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitUnique(GeneratedYangParser.UniqueContext ctx) {
     public void exitUnique(GeneratedYangParser.UniqueContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterRefine(GeneratedYangParser.RefineContext ctx) {
     public void enterRefine(GeneratedYangParser.RefineContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitRefine(GeneratedYangParser.RefineContext ctx) {
     public void exitRefine(GeneratedYangParser.RefineContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterAugment(GeneratedYangParser.AugmentContext ctx) {
     public void enterAugment(GeneratedYangParser.AugmentContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitAugment(GeneratedYangParser.AugmentContext ctx) {
     public void exitAugment(GeneratedYangParser.AugmentContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterDeviation(GeneratedYangParser.DeviationContext ctx) {
     public void enterDeviation(GeneratedYangParser.DeviationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitDeviation(GeneratedYangParser.DeviationContext ctx) {
     public void exitDeviation(GeneratedYangParser.DeviationContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterYangConstruct(GeneratedYangParser.YangConstructContext ctx) {
     public void enterYangConstruct(GeneratedYangParser.YangConstructContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitYangConstruct(GeneratedYangParser.YangConstructContext ctx) {
     public void exitYangConstruct(GeneratedYangParser.YangConstructContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterVersion(GeneratedYangParser.VersionContext ctx) {
     public void enterVersion(GeneratedYangParser.VersionContext ctx) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitVersion(GeneratedYangParser.VersionContext ctx) {
     public void exitVersion(GeneratedYangParser.VersionContext ctx) {
+        // do nothing.
+    }
+
+    @Override
+    public void enterValue(GeneratedYangParser.ValueContext ctx) {
+        // do nothing.
+    }
+
+    @Override
+    public void exitValue(GeneratedYangParser.ValueContext ctx) {
+        // do nothing.
+    }
+
+    @Override
+    public void enterFraction(GeneratedYangParser.FractionContext ctx) {
         // TODO: implement the method.
         // TODO: implement the method.
     }
     }
 
 
     @Override
     @Override
-    public void visitTerminal(TerminalNode terminalNode) {
+    public void exitFraction(GeneratedYangParser.FractionContext ctx) {
         // TODO: implement the method.
         // TODO: implement the method.
     }
     }
 
 
     @Override
     @Override
+    public void visitTerminal(TerminalNode terminalNode) {
+        // do nothing.
+    }
+
+    @Override
     public void visitErrorNode(ErrorNode errorNode) {
     public void visitErrorNode(ErrorNode errorNode) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void enterEveryRule(ParserRuleContext parserRuleContext) {
     public void enterEveryRule(ParserRuleContext parserRuleContext) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 
 
     @Override
     @Override
     public void exitEveryRule(ParserRuleContext parserRuleContext) {
     public void exitEveryRule(ParserRuleContext parserRuleContext) {
-        // TODO: implement the method.
+        // do nothing.
     }
     }
 }
 }

@@ -26,6 +26,7 @@ import org.onosproject.yangutils.datamodel.YangModule;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNotification;
 import org.onosproject.yangutils.datamodel.YangNotification;
 import org.onosproject.yangutils.datamodel.YangOutput;
 import org.onosproject.yangutils.datamodel.YangOutput;
+import org.onosproject.yangutils.datamodel.YangSubModule;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
@@ -133,12 +134,11 @@ public final class ContainerListener {
         }
         }
 
 
         Parsable curData = listener.getParsedDataStack().peek();
         Parsable curData = listener.getParsedDataStack().peek();
-        if (curData instanceof YangModule || curData instanceof YangContainer
-                || curData instanceof YangList || curData instanceof YangCase
-                || curData instanceof YangNotification
+        if (curData instanceof YangModule || curData instanceof YangSubModule
+                || curData instanceof YangContainer || curData instanceof YangList
+                || curData instanceof YangCase || curData instanceof YangNotification
                 || curData instanceof YangInput || curData instanceof YangOutput
                 || curData instanceof YangInput || curData instanceof YangOutput
-                || curData instanceof YangAugment
-                || curData instanceof YangGrouping) {
+                || curData instanceof YangAugment || curData instanceof YangGrouping) {
             YangNode curNode = (YangNode) curData;
             YangNode curNode = (YangNode) curData;
             try {
             try {
                 curNode.addChild(container);
                 curNode.addChild(container);

@@ -39,6 +39,8 @@ package org.onosproject.yangutils.parser.impl.listeners;
  * defaultStatement : DEFAULT_KEYWORD string STMTEND;
  * defaultStatement : DEFAULT_KEYWORD string STMTEND;
  */
  */
 
 
+import org.onosproject.yangutils.datamodel.YangChoice;
+import org.onosproject.yangutils.datamodel.YangLeaf;
 import org.onosproject.yangutils.datamodel.YangTypeDef;
 import org.onosproject.yangutils.datamodel.YangTypeDef;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
@@ -83,6 +85,16 @@ public final class DefaultListener {
                 typeDef.setDefaultValueInString(ctx.string().getText());
                 typeDef.setDefaultValueInString(ctx.string().getText());
                 break;
                 break;
             }
             }
+            case LEAF_DATA: {
+                YangLeaf leaf = (YangLeaf) tmpNode;
+                leaf.setDefaultValueInString(ctx.string().getText());
+                break;
+            }
+            case CHOICE_DATA: {
+                YangChoice choice = (YangChoice) tmpNode;
+                choice.setDefaultValueInString(ctx.string().getText());
+                break;
+            }
             default:
             default:
                 throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER,
                 throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER,
                         DEFAULT_DATA, ctx.string().getText(), ENTRY));
                         DEFAULT_DATA, ctx.string().getText(), ENTRY));

@@ -146,7 +146,14 @@ public final class EnumListener {
                         boolean isValuePresent = false;
                         boolean isValuePresent = false;
 
 
                         for (YangEnum curEnum : yangEnumeration.getEnumSet()) {
                         for (YangEnum curEnum : yangEnumeration.getEnumSet()) {
-                            if (maxValue <= curEnum.getValue()) {
+                            if (curEnum.getValue() == Integer.MAX_VALUE) {
+                                ParserException parserException = new ParserException("YANG file error : "
+                                        + "An enum value MUST be specified for enum substatements following the one"
+                                        + "with the current highest value");
+                                parserException.setLine(ctx.getStart().getLine());
+                                parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+                                throw parserException;
+                            } else if (maxValue <= curEnum.getValue()) {
                                 maxValue = curEnum.getValue();
                                 maxValue = curEnum.getValue();
                                 isValuePresent = true;
                                 isValuePresent = true;
                             }
                             }
@@ -161,8 +168,8 @@ public final class EnumListener {
                     } catch (DataModelException e) {
                     } catch (DataModelException e) {
                         ParserException parserException = new ParserException(constructExtendedListenerErrorMessage(
                         ParserException parserException = new ParserException(constructExtendedListenerErrorMessage(
                                 DUPLICATE_ENTRY, ENUM_DATA, ctx.string().getText(), EXIT, e.getMessage()));
                                 DUPLICATE_ENTRY, ENUM_DATA, ctx.string().getText(), EXIT, e.getMessage()));
-                        parserException.setLine(ctx.string().STRING(0).getSymbol().getLine());
-                        parserException.setCharPosition(ctx.string().STRING(0).getSymbol().getCharPositionInLine());
+                        parserException.setLine(ctx.getStart().getLine());
+                        parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
                         throw parserException;
                         throw parserException;
                     }
                     }
                     break;
                     break;
@@ -173,8 +180,7 @@ public final class EnumListener {
             }
             }
         } else {
         } else {
             throw new ParserException(
             throw new ParserException(
-                    constructListenerErrorMessage(MISSING_CURRENT_HOLDER, ENUM_DATA, ctx.string().getText(),
-                            EXIT));
+                    constructListenerErrorMessage(MISSING_CURRENT_HOLDER, ENUM_DATA, ctx.string().getText(), EXIT));
         }
         }
     }
     }
 }
 }

@@ -29,8 +29,10 @@ import org.onosproject.yangutils.utils.YangConstructType;
 
 
 import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
 import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 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.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+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.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.utils.RestrictionResolver.processLengthRestriction;
 import static org.onosproject.yangutils.utils.RestrictionResolver.processLengthRestriction;
@@ -86,7 +88,7 @@ public final class LengthRestrictionListener {
         Parsable tmpData = listener.getParsedDataStack().peek();
         Parsable tmpData = listener.getParsedDataStack().peek();
         if (tmpData.getYangConstructType() == TYPE_DATA) {
         if (tmpData.getYangConstructType() == TYPE_DATA) {
             YangType type = (YangType) tmpData;
             YangType type = (YangType) tmpData;
-            setLengthRestriction(type, ctx);
+            setLengthRestriction(listener, type, ctx);
         } else {
         } else {
             throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LENGTH_DATA,
             throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LENGTH_DATA,
                     ctx.length().getText(), ENTRY));
                     ctx.length().getText(), ENTRY));
@@ -96,10 +98,11 @@ public final class LengthRestrictionListener {
     /**
     /**
      * Sets the length restriction to type.
      * Sets the length restriction to type.
      *
      *
+     * @param listener listener's object
      * @param type Yang type for which length restriction to be set
      * @param type Yang type for which length restriction to be set
      * @param ctx  context object of the grammar rule
      * @param ctx  context object of the grammar rule
      */
      */
-    private static void setLengthRestriction(YangType type,
+    private static void setLengthRestriction(TreeWalkListener listener, YangType type,
                                              GeneratedYangParser.LengthStatementContext ctx) {
                                              GeneratedYangParser.LengthStatementContext ctx) {
 
 
         if (type.getDataType() == DERIVED) {
         if (type.getDataType() == DERIVED) {
@@ -132,5 +135,31 @@ public final class LengthRestrictionListener {
         }
         }
 
 
         stringRestriction.setLengthRestriction(lengthRestriction);
         stringRestriction.setLengthRestriction(lengthRestriction);
+        listener.getParsedDataStack().push(lengthRestriction);
+    }
+
+    /**
+     * Performs validation and updates the data model tree.
+     * It is called when parser exits from grammar rule (length).
+     *
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processLengthRestrictionExit(TreeWalkListener listener,
+                                                   GeneratedYangParser.LengthStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, LENGTH_DATA, ctx.length().getText(), EXIT);
+
+        Parsable tmpData = listener.getParsedDataStack().peek();
+        if (tmpData instanceof YangRangeRestriction) {
+            listener.getParsedDataStack().pop();
+        } else if (tmpData instanceof YangType
+                && ((YangType) tmpData).getDataType() == DERIVED) {
+            // TODO : need to handle in linker
+        } else {
+            throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, LENGTH_DATA,
+                    ctx.length().getText(), EXIT));
+        }
     }
     }
 }
 }

@@ -26,6 +26,7 @@ import org.onosproject.yangutils.datamodel.YangModule;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNotification;
 import org.onosproject.yangutils.datamodel.YangNotification;
 import org.onosproject.yangutils.datamodel.YangOutput;
 import org.onosproject.yangutils.datamodel.YangOutput;
+import org.onosproject.yangutils.datamodel.YangSubModule;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
@@ -141,7 +142,8 @@ public final class ListListener {
         if (curData instanceof YangModule || curData instanceof YangContainer
         if (curData instanceof YangModule || curData instanceof YangContainer
                 || curData instanceof YangList || curData instanceof YangCase
                 || curData instanceof YangList || curData instanceof YangCase
                 || curData instanceof YangNotification || curData instanceof YangInput
                 || curData instanceof YangNotification || curData instanceof YangInput
-                || curData instanceof YangOutput || curData instanceof YangAugment || curData instanceof YangGrouping) {
+                || curData instanceof YangOutput || curData instanceof YangAugment
+                || curData instanceof YangGrouping || curData instanceof YangSubModule) {
             curNode = (YangNode) curData;
             curNode = (YangNode) curData;
             try {
             try {
                 curNode.addChild(yangList);
                 curNode.addChild(yangList);

@@ -27,9 +27,12 @@ import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 import org.onosproject.yangutils.utils.YangConstructType;
 import org.onosproject.yangutils.utils.YangConstructType;
 
 
+import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 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.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+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.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.utils.YangConstructType.PATTERN_DATA;
 import static org.onosproject.yangutils.utils.YangConstructType.PATTERN_DATA;
@@ -84,7 +87,7 @@ public final class PatternRestrictionListener {
         Parsable tmpData = listener.getParsedDataStack().peek();
         Parsable tmpData = listener.getParsedDataStack().peek();
         if (tmpData.getYangConstructType() == TYPE_DATA) {
         if (tmpData.getYangConstructType() == TYPE_DATA) {
             YangType type = (YangType) tmpData;
             YangType type = (YangType) tmpData;
-            setPatternRestriction(type, ctx);
+            setPatternRestriction(listener, type, ctx);
         } else {
         } else {
             throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, PATTERN_DATA,
             throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, PATTERN_DATA,
                     ctx.string().getText(), ENTRY));
                     ctx.string().getText(), ENTRY));
@@ -94,10 +97,11 @@ public final class PatternRestrictionListener {
     /**
     /**
      * Sets the pattern restriction to type.
      * Sets the pattern restriction to type.
      *
      *
+     * @param listener listener's object
      * @param type Yang type for which pattern restriction to be set
      * @param type Yang type for which pattern restriction to be set
      * @param ctx  context object of the grammar rule
      * @param ctx  context object of the grammar rule
      */
      */
-    private static void setPatternRestriction(YangType type,
+    private static void setPatternRestriction(TreeWalkListener listener, YangType type,
                                               GeneratedYangParser.PatternStatementContext ctx) {
                                               GeneratedYangParser.PatternStatementContext ctx) {
 
 
         if (type.getDataType() != YangDataTypes.STRING && type.getDataType() != YangDataTypes.DERIVED) {
         if (type.getDataType() != YangDataTypes.STRING && type.getDataType() != YangDataTypes.DERIVED) {
@@ -121,6 +125,7 @@ public final class PatternRestrictionListener {
             } else {
             } else {
                 stringRestriction.addPattern(patternArgument);
                 stringRestriction.addPattern(patternArgument);
             }
             }
+            listener.getParsedDataStack().push(stringRestriction);
         } else {
         } else {
             YangPatternRestriction patternRestriction = (YangPatternRestriction) ((YangDerivedInfo<?>) type
             YangPatternRestriction patternRestriction = (YangPatternRestriction) ((YangDerivedInfo<?>) type
                     .getDataTypeExtendedInfo()).getPatternRestriction();
                     .getDataTypeExtendedInfo()).getPatternRestriction();
@@ -134,4 +139,29 @@ public final class PatternRestrictionListener {
             }
             }
         }
         }
     }
     }
+
+    /**
+     * Performs validation and updates the data model tree.
+     * It is called when parser exits from grammar rule (pattern).
+     *
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processPatternRestrictionExit(TreeWalkListener listener,
+                                                    GeneratedYangParser.PatternStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, PATTERN_DATA, ctx.string().getText(), EXIT);
+
+        Parsable tmpData = listener.getParsedDataStack().peek();
+        if (tmpData instanceof YangStringRestriction) {
+            listener.getParsedDataStack().pop();
+        } else if (tmpData instanceof YangType
+                && ((YangType) tmpData).getDataType() == DERIVED) {
+            // TODO : need to handle in linker
+        } else {
+            throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, PATTERN_DATA,
+                    ctx.string().getText(), EXIT));
+        }
+    }
 }
 }

@@ -26,8 +26,10 @@ import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
 
 import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
 import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 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.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+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.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.utils.RestrictionResolver.isOfRangeRestrictedType;
 import static org.onosproject.yangutils.utils.RestrictionResolver.isOfRangeRestrictedType;
@@ -82,7 +84,7 @@ public final class RangeRestrictionListener {
         Parsable tmpData = listener.getParsedDataStack().peek();
         Parsable tmpData = listener.getParsedDataStack().peek();
         if (tmpData.getYangConstructType() == TYPE_DATA) {
         if (tmpData.getYangConstructType() == TYPE_DATA) {
             YangType type = (YangType) tmpData;
             YangType type = (YangType) tmpData;
-            setRangeRestriction(type, ctx);
+            setRangeRestriction(listener, type, ctx);
         } else {
         } else {
             throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, RANGE_DATA,
             throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, RANGE_DATA,
                     ctx.range().getText(), ENTRY));
                     ctx.range().getText(), ENTRY));
@@ -92,10 +94,11 @@ public final class RangeRestrictionListener {
     /**
     /**
      * Sets the range restriction to type.
      * Sets the range restriction to type.
      *
      *
+     * @param listener listener's object
      * @param type YANG type for which range restriction to be added
      * @param type YANG type for which range restriction to be added
      * @param ctx  context object of the grammar rule
      * @param ctx  context object of the grammar rule
      */
      */
-    private static void setRangeRestriction(YangType type,
+    private static void setRangeRestriction(TreeWalkListener listener, YangType type,
                                             GeneratedYangParser.RangeStatementContext ctx) {
                                             GeneratedYangParser.RangeStatementContext ctx) {
 
 
         if (type.getDataType() == DERIVED) {
         if (type.getDataType() == DERIVED) {
@@ -122,5 +125,31 @@ public final class RangeRestrictionListener {
         if (rangeRestriction != null) {
         if (rangeRestriction != null) {
             type.setDataTypeExtendedInfo(rangeRestriction);
             type.setDataTypeExtendedInfo(rangeRestriction);
         }
         }
+        listener.getParsedDataStack().push(rangeRestriction);
+    }
+
+    /**
+     * Performs validation and updates the data model tree.
+     * It is called when parser exits from grammar rule (range).
+     *
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processRangeRestrictionExit(TreeWalkListener listener,
+                                       GeneratedYangParser.RangeStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, RANGE_DATA, ctx.range().getText(), EXIT);
+
+        Parsable tmpData = listener.getParsedDataStack().peek();
+        if (tmpData instanceof YangRangeRestriction) {
+            listener.getParsedDataStack().pop();
+        } else if (tmpData instanceof YangType
+                && ((YangType) tmpData).getDataType() == DERIVED) {
+            // TODO : need to handle in linker
+        } else {
+            throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, RANGE_DATA,
+                    ctx.range().getText(), EXIT));
+        }
     }
     }
 }
 }
\ No newline at end of file

@@ -38,6 +38,7 @@ import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMes
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIntegerValue;
 import static org.onosproject.yangutils.utils.YangConstructType.VALUE_DATA;
 import static org.onosproject.yangutils.utils.YangConstructType.VALUE_DATA;
 
 
 /**
 /**
@@ -62,25 +63,28 @@ public final class ValueListener {
     public static void processValueEntry(TreeWalkListener listener, GeneratedYangParser.ValueStatementContext ctx) {
     public static void processValueEntry(TreeWalkListener listener, GeneratedYangParser.ValueStatementContext ctx) {
 
 
         // Check for stack to be non empty.
         // Check for stack to be non empty.
-        checkStackIsNotEmpty(listener, MISSING_HOLDER, VALUE_DATA, ctx.INTEGER().getText(), ENTRY);
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, VALUE_DATA, ctx.value().getText(), ENTRY);
+
+        // Validate value
+        int value = getValidIntegerValue(ctx.value().getText(), VALUE_DATA, ctx);
 
 
         // Obtain the node of the stack.
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
         Parsable tmpNode = listener.getParsedDataStack().peek();
         switch (tmpNode.getYangConstructType()) {
         switch (tmpNode.getYangConstructType()) {
             case ENUM_DATA: {
             case ENUM_DATA: {
                 YangEnum enumNode = (YangEnum) tmpNode;
                 YangEnum enumNode = (YangEnum) tmpNode;
-                if (!isEnumValueValid(listener, ctx)) {
+                if (!isEnumValueValid(listener, ctx, value)) {
                     ParserException parserException = new ParserException("Duplicate Value Entry");
                     ParserException parserException = new ParserException("Duplicate Value Entry");
-                    parserException.setLine(ctx.INTEGER().getSymbol().getLine());
-                    parserException.setCharPosition(ctx.INTEGER().getSymbol().getCharPositionInLine());
+                    parserException.setLine(ctx.getStart().getLine());
+                    parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
                     throw parserException;
                     throw parserException;
                 }
                 }
-                enumNode.setValue(Integer.valueOf(ctx.INTEGER().getText()));
+                enumNode.setValue(value);
                 break;
                 break;
             }
             }
             default:
             default:
                 throw new ParserException(
                 throw new ParserException(
-                        constructListenerErrorMessage(INVALID_HOLDER, VALUE_DATA, ctx.INTEGER().getText(), ENTRY));
+                        constructListenerErrorMessage(INVALID_HOLDER, VALUE_DATA, ctx.value().getText(), ENTRY));
         }
         }
     }
     }
 
 
@@ -89,20 +93,22 @@ public final class ValueListener {
      *
      *
      * @param listener Listener's object
      * @param listener Listener's object
      * @param ctx context object of the grammar rule
      * @param ctx context object of the grammar rule
+     * @param value enum value
      * @return validation result
      * @return validation result
      */
      */
-    private static boolean isEnumValueValid(TreeWalkListener listener, GeneratedYangParser.ValueStatementContext ctx) {
+    private static boolean isEnumValueValid(TreeWalkListener listener, GeneratedYangParser.ValueStatementContext ctx,
+            int value) {
         Parsable enumNode = listener.getParsedDataStack().pop();
         Parsable enumNode = listener.getParsedDataStack().pop();
 
 
         // Check for stack to be non empty.
         // Check for stack to be non empty.
-        checkStackIsNotEmpty(listener, MISSING_HOLDER, VALUE_DATA, ctx.INTEGER().getText(), ENTRY);
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, VALUE_DATA, ctx.value().getText(), ENTRY);
 
 
         Parsable tmpNode = listener.getParsedDataStack().peek();
         Parsable tmpNode = listener.getParsedDataStack().peek();
         switch (tmpNode.getYangConstructType()) {
         switch (tmpNode.getYangConstructType()) {
             case ENUMERATION_DATA: {
             case ENUMERATION_DATA: {
                 YangEnumeration yangEnumeration = (YangEnumeration) tmpNode;
                 YangEnumeration yangEnumeration = (YangEnumeration) tmpNode;
                 for (YangEnum curEnum : yangEnumeration.getEnumSet()) {
                 for (YangEnum curEnum : yangEnumeration.getEnumSet()) {
-                    if (Integer.valueOf(ctx.INTEGER().getText()) == curEnum.getValue()) {
+                    if (value == curEnum.getValue()) {
                         listener.getParsedDataStack().push(enumNode);
                         listener.getParsedDataStack().push(enumNode);
                         return false;
                         return false;
                     }
                     }
@@ -113,7 +119,7 @@ public final class ValueListener {
             default:
             default:
                 listener.getParsedDataStack().push(enumNode);
                 listener.getParsedDataStack().push(enumNode);
                 throw new ParserException(
                 throw new ParserException(
-                        constructListenerErrorMessage(INVALID_HOLDER, VALUE_DATA, ctx.INTEGER().getText(), ENTRY));
+                        constructListenerErrorMessage(INVALID_HOLDER, VALUE_DATA, ctx.value().getText(), ENTRY));
         }
         }
     }
     }
 }
 }

@@ -29,6 +29,18 @@ import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.utils.YangConstructType;
 import org.onosproject.yangutils.utils.YangConstructType;
 
 
+import static org.onosproject.yangutils.utils.UtilConstants.ADD;
+import static org.onosproject.yangutils.utils.UtilConstants.SPACE;
+import static org.onosproject.yangutils.utils.UtilConstants.SLASH;
+import static org.onosproject.yangutils.utils.UtilConstants.COLON;
+import static org.onosproject.yangutils.utils.UtilConstants.CARET;
+import static org.onosproject.yangutils.utils.UtilConstants.QUOTES;
+import static org.onosproject.yangutils.utils.UtilConstants.HYPHEN;
+import static org.onosproject.yangutils.utils.UtilConstants.EMPTY_STRING;
+import static org.onosproject.yangutils.utils.UtilConstants.TRUE;
+import static org.onosproject.yangutils.utils.UtilConstants.FALSE;
+import static org.onosproject.yangutils.utils.UtilConstants.YANG_FILE_ERROR;
+
 /**
 /**
  * Represents an utility for listener.
  * Represents an utility for listener.
  */
  */
@@ -37,18 +49,10 @@ public final class ListenerUtil {
     private static final Pattern IDENTIFIER_PATTERN = Pattern.compile("[a-zA-Z_][a-zA-Z0-9_.-]*");
     private static final Pattern IDENTIFIER_PATTERN = Pattern.compile("[a-zA-Z_][a-zA-Z0-9_.-]*");
     private static final String DATE_PATTERN = "[0-9]{4}-([0-9]{2}|[0-9])-([0-9]{2}|[0-9])";
     private static final String DATE_PATTERN = "[0-9]{4}-([0-9]{2}|[0-9])-([0-9]{2}|[0-9])";
     private static final String NON_NEGATIVE_INTEGER_PATTERN = "[0-9]+";
     private static final String NON_NEGATIVE_INTEGER_PATTERN = "[0-9]+";
-    private static final String PLUS = "+";
+    private static final Pattern INTEGER_PATTERN = Pattern.compile("[-][0-9]+|[0-9]+");
     private static final String ONE = "1";
     private static final String ONE = "1";
-    private static final String TRUE_KEYWORD = "true";
-    private static final String FALSE_KEYWORD = "false";
     private static final int IDENTIFIER_LENGTH = 64;
     private static final int IDENTIFIER_LENGTH = 64;
     private static final String DATE_FORMAT = "yyyy-MM-dd";
     private static final String DATE_FORMAT = "yyyy-MM-dd";
-    private static final String EMPTY_STRING = "";
-    private static final String HYPHEN = "-";
-    private static final String SLASH = "/";
-    private static final String SPACE = " ";
-    private static final String COLON = ":";
-    private static final String CARET = "^";
 
 
     /**
     /**
      * Creates a new listener util.
      * Creates a new listener util.
@@ -65,7 +69,7 @@ public final class ListenerUtil {
     public static String removeQuotesAndHandleConcat(String yangStringData) {
     public static String removeQuotesAndHandleConcat(String yangStringData) {
 
 
         yangStringData = yangStringData.replace("\"", EMPTY_STRING);
         yangStringData = yangStringData.replace("\"", EMPTY_STRING);
-        String[] tmpData = yangStringData.split(Pattern.quote(PLUS));
+        String[] tmpData = yangStringData.split(Pattern.quote(ADD));
         StringBuilder builder = new StringBuilder();
         StringBuilder builder = new StringBuilder();
         for (String yangString : tmpData) {
         for (String yangString : tmpData) {
             builder.append(yangString);
             builder.append(yangString);
@@ -171,6 +175,41 @@ public final class ListenerUtil {
     }
     }
 
 
     /**
     /**
+     * Validates integer value.
+     *
+     * @param integerValue integer to be validated
+     * @param yangConstruct yang construct for creating error message
+     * @param ctx context object of the grammar rule
+     * @return valid integer value
+     */
+    public static int getValidIntegerValue(String integerValue, YangConstructType yangConstruct,
+                                                      ParserRuleContext ctx) {
+
+        String value = removeQuotesAndHandleConcat(integerValue);
+        if (!INTEGER_PATTERN.matcher(value).matches()) {
+            ParserException parserException = new ParserException("YANG file error : " +
+                    YangConstructType.getYangConstructType(yangConstruct) + " value " + value + " is not " +
+                    "valid.");
+            parserException.setLine(ctx.getStart().getLine());
+            parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+            throw parserException;
+        }
+
+        int valueInInteger;
+        try {
+            valueInInteger = Integer.parseInt(value);
+        } catch (NumberFormatException e) {
+            ParserException parserException = new ParserException("YANG file error : " +
+                    YangConstructType.getYangConstructType(yangConstruct) + " value " + value + " is not " +
+                    "valid.");
+            parserException.setLine(ctx.getStart().getLine());
+            parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+            throw parserException;
+        }
+        return valueInInteger;
+    }
+
+    /**
      * Validates boolean value.
      * Validates boolean value.
      *
      *
      * @param booleanValue value to be validated
      * @param booleanValue value to be validated
@@ -182,9 +221,9 @@ public final class ListenerUtil {
             ParserRuleContext ctx) {
             ParserRuleContext ctx) {
 
 
         String value = removeQuotesAndHandleConcat(booleanValue);
         String value = removeQuotesAndHandleConcat(booleanValue);
-        if (value.equals(TRUE_KEYWORD)) {
+        if (value.equals(TRUE)) {
             return true;
             return true;
-        } else if (value.equals(FALSE_KEYWORD)) {
+        } else if (value.equals(FALSE)) {
             return false;
             return false;
         } else {
         } else {
             ParserException parserException = new ParserException("YANG file error : " +
             ParserException parserException = new ParserException("YANG file error : " +
@@ -272,4 +311,21 @@ public final class ListenerUtil {
         }
         }
         return targetNodes;
         return targetNodes;
     }
     }
+
+    /**
+     * Throws parser exception for unsupported YANG constructs.
+     *
+     * @param yangConstructType yang construct for creating error message
+     * @param ctx yang construct's context to get the line number and character position
+     * @param errorInfo error information
+     */
+    public static void handleUnsupportedYangConstruct(YangConstructType yangConstructType,
+        ParserRuleContext ctx, String errorInfo) {
+        ParserException parserException = new ParserException(YANG_FILE_ERROR
+                + QUOTES + YangConstructType.getYangConstructType(yangConstructType) + QUOTES
+                + errorInfo);
+        parserException.setLine(ctx.getStart().getLine());
+        parserException.setCharPosition(ctx.getStart().getCharPositionInLine());
+        throw parserException;
+    }
 }
 }
\ No newline at end of file

+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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 at
+ *
+ *     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 org.onosproject.yangutils.plugin.manager;
+
+import org.onosproject.yangutils.datamodel.YangNode;
+
+/**
+ * Represents YANG file information.
+ */
+public class YangFileInfo {
+
+    /**
+     * YANG file name.
+     */
+    private String yangFileName;
+
+    /**
+     * Data model node after parsing YANG file.
+     */
+    private YangNode rootNode;
+
+    /**
+     * Returns data model node for YANG file.
+     *
+     * @return data model node for YANG file
+     */
+    public YangNode getRootNode() {
+        return rootNode;
+    }
+
+    /**
+     * Sets data model node for YANG file.
+     *
+     * @param rootNode of the Yang file
+     */
+    public void setRootNode(YangNode rootNode) {
+        this.rootNode = rootNode;
+    }
+
+    /**
+     * Returns YANG file name.
+     *
+     * @return yangFileName YANG file name
+     */
+    public String getYangFileName() {
+        return yangFileName;
+    }
+
+    /**
+     * Sets YANG file name.
+     *
+     * @param yangFileName YANG file name
+     */
+    public void setYangFileName(String yangFileName) {
+        this.yangFileName = yangFileName;
+    }
+}

@@ -28,6 +28,8 @@ import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.MavenProject;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.YangUtilsParser;
 import org.onosproject.yangutils.parser.YangUtilsParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
 import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
@@ -49,6 +51,7 @@ import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.addToSource;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.copyYangFilesToTarget;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.copyYangFilesToTarget;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.getDirectory;
 import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.getDirectory;
+import static org.onosproject.yangutils.datamodel.utils.DataModelUtils.findBelongsToModuleNode;
 
 
 /**
 /**
  * Represents ONOS YANG utility maven plugin.
  * Represents ONOS YANG utility maven plugin.
@@ -137,17 +140,22 @@ public class YangUtilManager extends AbstractMojo {
             conflictResolver.setReplacementForPeriod(replacementForPeriod);
             conflictResolver.setReplacementForPeriod(replacementForPeriod);
             conflictResolver.setReplacementForHyphen(replacementForHyphen);
             conflictResolver.setReplacementForHyphen(replacementForHyphen);
             conflictResolver.setReplacementForUnderscore(replacementForUnderscore);
             conflictResolver.setReplacementForUnderscore(replacementForUnderscore);
-            List<String> yangFiles = YangFileScanner.getYangFiles(searchDir);
+            List<YangFileInfo> yangFileInfo = YangFileScanner.getYangFiles(searchDir);
+            if (yangFileInfo == null || yangFileInfo.isEmpty()) {
+                // no files to translate
+                return;
+            }
             YangPluginConfig yangPlugin = new YangPluginConfig();
             YangPluginConfig yangPlugin = new YangPluginConfig();
             yangPlugin.setCodeGenDir(codeGenDir);
             yangPlugin.setCodeGenDir(codeGenDir);
             yangPlugin.setConflictResolver(conflictResolver);
             yangPlugin.setConflictResolver(conflictResolver);
-            Iterator<String> yangFileIterator = yangFiles.iterator();
+
+            Iterator<YangFileInfo> yangFileIterator = yangFileInfo.iterator();
             while (yangFileIterator.hasNext()) {
             while (yangFileIterator.hasNext()) {
-                String yangFile = yangFileIterator.next();
+                YangFileInfo yangFile = yangFileIterator.next();
                 try {
                 try {
-                    YangNode yangNode = yangUtilsParser.getDataModel(yangFile);
+                    YangNode yangNode = yangUtilsParser.getDataModel(yangFile.getYangFileName());
+                    yangFile.setRootNode(yangNode);
                     setRootNode(yangNode);
                     setRootNode(yangNode);
-                    generateJavaCode(yangNode, yangPlugin, yangFile);
                 } catch (ParserException e) {
                 } catch (ParserException e) {
                     String logInfo = "Error in file: " + e.getFileName();
                     String logInfo = "Error in file: " + e.getFileName();
                     if (e.getLineNumber() != 0) {
                     if (e.getLineNumber() != 0) {
@@ -163,8 +171,12 @@ public class YangUtilManager extends AbstractMojo {
                 }
                 }
             }
             }
 
 
+            resolveLinkingForSubModule(yangFileInfo);
+
+            translateToJava(yangFileInfo, yangPlugin);
+
             addToSource(getDirectory(baseDir, genFilesDir) + DEFAULT_PKG, project, context);
             addToSource(getDirectory(baseDir, genFilesDir) + DEFAULT_PKG, project, context);
-            copyYangFilesToTarget(yangFiles, getDirectory(baseDir, outputDirectory), project);
+            copyYangFilesToTarget(yangFileInfo, getDirectory(baseDir, outputDirectory), project);
         } catch (Exception e) {
         } catch (Exception e) {
             String fileName = "";
             String fileName = "";
             if (e instanceof TranslatorException) {
             if (e instanceof TranslatorException) {
@@ -220,4 +232,40 @@ public class YangUtilManager extends AbstractMojo {
         this.rootNode = rootNode;
         this.rootNode = rootNode;
     }
     }
 
 
+    /**
+     * Translates to java code corresponding to the YANG schema.
+     *
+     * @param yangFileInfo YANG file information
+     * @param yangPlugin YANG plugin config
+     * @throws IOException when fails to generate java code file the current
+     *             node
+     */
+    public static void translateToJava(List<YangFileInfo> yangFileInfo, YangPluginConfig yangPlugin)
+            throws IOException {
+        Iterator<YangFileInfo> yangFileIterator = yangFileInfo.iterator();
+        while (yangFileIterator.hasNext()) {
+            YangFileInfo yangFile = yangFileIterator.next();
+            generateJavaCode(yangFile.getRootNode(), yangPlugin, yangFile.getYangFileName());
+        }
+    }
+
+    /**
+     * Resolves sub-module linking.
+     *
+     * @param yangFileInfo YANG file information
+     * @throws DataModelException when belongs-to module node is not found
+     */
+    public static void resolveLinkingForSubModule(List<YangFileInfo> yangFileInfo) throws DataModelException {
+        Iterator<YangFileInfo> yangFileIterator = yangFileInfo.iterator();
+        while (yangFileIterator.hasNext()) {
+            YangFileInfo yangFile = yangFileIterator.next();
+            YangNode yangNode = yangFile.getRootNode();
+            if (yangNode instanceof YangSubModule) {
+                String belongsToModuleName = ((YangSubModule) yangNode).getBelongsTo()
+                        .getBelongsToModuleName();
+                YangNode moduleNode = findBelongsToModuleNode(yangFileInfo, belongsToModuleName);
+                ((YangSubModule) yangNode).getBelongsTo().setModuleNode(moduleNode);
+            }
+        }
+    }
 }
 }

@@ -18,6 +18,7 @@ package org.onosproject.yangutils.translator.tojava.javamodel;
 import java.io.IOException;
 import java.io.IOException;
 
 
 import org.onosproject.yangutils.datamodel.YangBelongsTo;
 import org.onosproject.yangutils.datamodel.YangBelongsTo;
+import org.onosproject.yangutils.datamodel.YangModule;
 import org.onosproject.yangutils.datamodel.YangSubModule;
 import org.onosproject.yangutils.datamodel.YangSubModule;
 import org.onosproject.yangutils.translator.exception.TranslatorException;
 import org.onosproject.yangutils.translator.exception.TranslatorException;
 import org.onosproject.yangutils.translator.tojava.JavaCodeGenerator;
 import org.onosproject.yangutils.translator.tojava.JavaCodeGenerator;
@@ -108,8 +109,7 @@ public class YangJavaSubModule
      * @return the name space string of the module.
      * @return the name space string of the module.
      */
      */
     private String getNameSpaceFromModule(YangBelongsTo belongsToInfo) {
     private String getNameSpaceFromModule(YangBelongsTo belongsToInfo) {
-        // TODO Auto-generated method stub
-        return "";
+        return ((YangModule) belongsToInfo.getModuleNode()).getNameSpace().getUri();
     }
     }
 
 
     /**
     /**

@@ -257,6 +257,16 @@ public final class UtilConstants {
     public static final String LISTENER_PKG = "org.onosproject.event";
     public static final String LISTENER_PKG = "org.onosproject.event";
 
 
     /**
     /**
+     * Static attribute for colon.
+     */
+    public static final String COLON = ":";
+
+    /**
+     * Static attribute for caret.
+     */
+    public static final String CARET = "^";
+
+    /**
      * Static attribute for input string.
      * Static attribute for input string.
      */
      */
     public static final String INPUT = "input";
     public static final String INPUT = "input";
@@ -932,6 +942,22 @@ public final class UtilConstants {
     public static final String YANG_UTILS_TODO = "//TODO: YANG utils generated code";
     public static final String YANG_UTILS_TODO = "//TODO: YANG utils generated code";
 
 
     /**
     /**
+     * Static attribute for YANG file error.
+     */
+    public static final String YANG_FILE_ERROR = "YANG file error : ";
+
+    /**
+     * Static attribute for unsupported error information.
+     */
+    public static final String UNSUPPORTED_YANG_CONSTRUCT = " is not supported.";
+
+    /**
+     * Static attribute for currently unsupported error information.
+     */
+    public static final String CURRENTLY_UNSUPPORTED = " is not supported in current version, please check wiki" +
+            " for YANG utils road map.";
+
+    /**
      * Creates an instance of util constants.
      * Creates an instance of util constants.
      */
      */
     private UtilConstants() {
     private UtilConstants() {

@@ -287,7 +287,77 @@ public enum YangConstructType {
     /**
     /**
      * Identifies the YANG pattern element parsed data.
      * Identifies the YANG pattern element parsed data.
      */
      */
-    PATTERN_DATA;
+    PATTERN_DATA,
+
+    /**
+     * Identifies the YANG extension element parsed data.
+     */
+    EXTENSION_DATA,
+
+    /**
+     * Identifies the YANG identity element parsed data.
+     */
+    IDENTITY_DATA,
+
+    /**
+     * Identifies the YANG base element parsed data.
+     */
+    BASE_DATA,
+
+    /**
+     * Identifies the YANG feature element parsed data.
+     */
+    FEATURE_DATA,
+
+    /**
+     * Identifies the YANG if-feature element parsed data.
+     */
+    IF_FEATURE_DATA,
+
+    /**
+     * Identifies the YANG path element parsed data.
+     */
+    PATH_DATA,
+
+    /**
+     * Identifies the YANG require-instance element parsed data.
+     */
+    REQUIRE_INSTANCE_DATA,
+
+    /**
+     * Identifies the YANG ordered-by element parsed data.
+     */
+    ORDERED_BY_DATA,
+
+    /**
+     * Identifies the YANG error-message element parsed data.
+     */
+    ERROR_MESSAGE_DATA,
+
+    /**
+     * Identifies the YANG error-app-tag element parsed data.
+     */
+    ERROR_APP_TAG_DATA,
+
+    /**
+     * Identifies the YANG unique element parsed data.
+     */
+    UNIQUE_DATA,
+
+    /**
+     * Identifies the YANG refine element parsed data.
+     */
+    REFINE_DATA,
+
+    /**
+     * Identifies the YANG deviation element parsed data.
+     */
+    DEVIATION_DATA,
+
+    /**
+     * Identifies the YANG anyxml element parsed data.
+     */
+    ANYXML_DATA;
 
 
     /**
     /**
      * Returns the YANG construct keyword corresponding to enum values.
      * Returns the YANG construct keyword corresponding to enum values.
@@ -406,6 +476,34 @@ public enum YangConstructType {
                 return "length";
                 return "length";
             case PATTERN_DATA:
             case PATTERN_DATA:
                 return "pattern";
                 return "pattern";
+            case EXTENSION_DATA:
+                return "extension";
+            case IDENTITY_DATA:
+                return "identity";
+            case BASE_DATA:
+                return "base";
+            case FEATURE_DATA:
+                return "feature";
+            case IF_FEATURE_DATA:
+                return "if-feature";
+            case PATH_DATA:
+                return "path";
+            case REQUIRE_INSTANCE_DATA:
+                return "require-instance";
+            case ORDERED_BY_DATA:
+                return "ordered-by";
+            case ERROR_MESSAGE_DATA:
+                return "error-message";
+            case ERROR_APP_TAG_DATA:
+                return "error-app-tag";
+            case UNIQUE_DATA:
+                return "unique";
+            case REFINE_DATA:
+                return "refine";
+            case DEVIATION_DATA:
+                return "deviation";
+            case ANYXML_DATA:
+                return "anyxml";
             default:
             default:
                 return "yang";
                 return "yang";
         }
         }

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.LinkedList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.List;
 import java.util.Stack;
 import java.util.Stack;
+import org.onosproject.yangutils.plugin.manager.YangFileInfo;
 
 
 /**
 /**
  * Represents utility for searching the files in a directory.
  * Represents utility for searching the files in a directory.
@@ -51,17 +52,23 @@ public final class YangFileScanner {
     }
     }
 
 
     /**
     /**
-     * Returns the list of YANG files.
+     * Returns the list of YANG file information.
      *
      *
      * @param root specified directory
      * @param root specified directory
-     * @return list of YANG files
+     * @return list of YANG file information
      * @throws NullPointerException when no files are there
      * @throws NullPointerException when no files are there
      * @throws IOException when files get deleted while performing the
      * @throws IOException when files get deleted while performing the
      *             operations
      *             operations
      */
      */
-    public static List<String> getYangFiles(String root) throws IOException {
-
-        return getFiles(root, YANG_FILE_EXTENTION);
+    public static List<YangFileInfo> getYangFiles(String root) throws IOException {
+        List<String> yangFiles = getFiles(root, YANG_FILE_EXTENTION);
+        List<YangFileInfo> fileInfo = new LinkedList<>();
+        for (String yangFile : yangFiles) {
+            YangFileInfo yangFileInfo = new YangFileInfo();
+            yangFileInfo.setYangFileName(yangFile);
+            fileInfo.add(yangFileInfo);
+        }
+        return fileInfo;
     }
     }
 
 
     /**
     /**

@@ -24,6 +24,7 @@ import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.LinkedList;
+import java.util.Iterator;
 import java.util.List;
 import java.util.List;
 import java.util.Stack;
 import java.util.Stack;
 
 
@@ -33,6 +34,7 @@ import org.apache.maven.project.MavenProject;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 import org.sonatype.plexus.build.incremental.BuildContext;
 import org.sonatype.plexus.build.incremental.BuildContext;
 
 
+import org.onosproject.yangutils.plugin.manager.YangFileInfo;
 import static org.onosproject.yangutils.utils.UtilConstants.COMMA;
 import static org.onosproject.yangutils.utils.UtilConstants.COMMA;
 import static org.onosproject.yangutils.utils.UtilConstants.EMPTY_STRING;
 import static org.onosproject.yangutils.utils.UtilConstants.EMPTY_STRING;
 import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
 import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
@@ -245,15 +247,15 @@ public final class YangIoUtils {
     /**
     /**
      * Copies YANG files to the current project's output directory.
      * Copies YANG files to the current project's output directory.
      *
      *
-     * @param yangFiles list of YANG files
+     * @param yangFileInfo list of YANG files
      * @param outputDir project's output directory
      * @param outputDir project's output directory
      * @param project maven project
      * @param project maven project
      * @throws IOException when fails to copy files to destination resource directory
      * @throws IOException when fails to copy files to destination resource directory
      */
      */
-    public static void copyYangFilesToTarget(List<String> yangFiles, String outputDir, MavenProject project)
+    public static void copyYangFilesToTarget(List<YangFileInfo> yangFileInfo, String outputDir, MavenProject project)
             throws IOException {
             throws IOException {
 
 
-        List<File> files = getListOfFile(yangFiles);
+        List<File> files = getListOfFile(yangFileInfo);
 
 
         String path = outputDir + TARGET_RESOURCE_PATH;
         String path = outputDir + TARGET_RESOURCE_PATH;
         File targetDir = new File(path);
         File targetDir = new File(path);
@@ -272,13 +274,15 @@ public final class YangIoUtils {
     /**
     /**
      * Provides a list of files from list of strings.
      * Provides a list of files from list of strings.
      *
      *
-     * @param strings list of strings
+     * @param yangFileInfo list of yang file information
      * @return list of files
      * @return list of files
      */
      */
-    private static List<File> getListOfFile(List<String> strings) {
+    private static List<File> getListOfFile(List<YangFileInfo> yangFileInfo) {
         List<File> files = new ArrayList<>();
         List<File> files = new ArrayList<>();
-        for (String file : strings) {
-            files.add(new File(file));
+        Iterator<YangFileInfo> yangFileIterator = yangFileInfo.iterator();
+        while (yangFileIterator.hasNext()) {
+            YangFileInfo yangFile = yangFileIterator.next();
+            files.add(new File(yangFile.getYangFileName()));
         }
         }
         return files;
         return files;
     }
     }

@@ -380,6 +380,7 @@ package org.onosproject.yangutils.parser.antlrgencode;
                     | leafListStatement
                     | leafListStatement
                     | listStatement
                     | listStatement
                     | choiceStatement
                     | choiceStatement
+                    | anyxmlStatement
                     | usesStatement;
                     | usesStatement;
 
 
     /**
     /**
@@ -429,13 +430,26 @@ package org.onosproject.yangutils.parser.antlrgencode;
      *                        instance-identifier-specification /
      *                        instance-identifier-specification /
      *                        bits-specification /
      *                        bits-specification /
      *                        union-specification
      *                        union-specification
-     * TODO : decimal64-specification to be added
+     *
      */
      */
-    typeBodyStatements : numericalRestrictions | stringRestrictions | enumSpecification
+    typeBodyStatements : numericalRestrictions | decimal64Specification | stringRestrictions | enumSpecification
                     | leafrefSpecification | identityrefSpecification | instanceIdentifierSpecification
                     | leafrefSpecification | identityrefSpecification | instanceIdentifierSpecification
                     | bitsSpecification | unionSpecification;
                     | bitsSpecification | unionSpecification;
 
 
     /**
     /**
+     *  fraction-digits-stmt = fraction-digits-keyword sep
+     *                         fraction-digits-arg-str stmtend
+     *
+     *  fraction-digits-arg-str = < a string that matches the rule
+     *                             fraction-digits-arg >
+     *
+     *  fraction-digits-arg = ("1" ["0" / "1" / "2" / "3" / "4" /
+     *                              "5" / "6" / "7" / "8"])
+     *                        / "2" / "3" / "4" / "5" / "6" / "7" / "8" / "9"
+     */
+    decimal64Specification : FRACTION_DIGITS_KEYWORD fraction STMTEND;
+
+    /**
      *  numerical-restrictions = range-stmt stmtsep
      *  numerical-restrictions = range-stmt stmtsep
      */
      */
     numericalRestrictions : rangeStatement;
     numericalRestrictions : rangeStatement;
@@ -746,7 +760,7 @@ package org.onosproject.yangutils.parser.antlrgencode;
     /**
     /**
      *  value-stmt          = value-keyword sep integer-value stmtend
      *  value-stmt          = value-keyword sep integer-value stmtend
      */
      */
-    valueStatement : VALUE_KEYWORD ((MINUS INTEGER) | INTEGER) STMTEND;
+    valueStatement : VALUE_KEYWORD value STMTEND;
 
 
     /**
     /**
      *   grouping-stmt       = grouping-keyword sep identifier-arg-str optsep
      *   grouping-stmt       = grouping-keyword sep identifier-arg-str optsep
@@ -899,7 +913,7 @@ package org.onosproject.yangutils.parser.antlrgencode;
      *                        list-stmt /
      *                        list-stmt /
      *                        anyxml-stmt
      *                        anyxml-stmt
      */
      */
-    shortCaseStatement : containerStatement | leafStatement | leafListStatement | listStatement;
+    shortCaseStatement : containerStatement | leafStatement | leafListStatement | listStatement | anyxmlStatement;
 
 
     /**
     /**
      *  case-stmt           = case-keyword sep identifier-arg-str optsep
      *  case-stmt           = case-keyword sep identifier-arg-str optsep
@@ -919,6 +933,25 @@ package org.onosproject.yangutils.parser.antlrgencode;
               | descriptionStatement | referenceStatement | dataDefStatement)* RIGHT_CURLY_BRACE);
               | descriptionStatement | referenceStatement | dataDefStatement)* RIGHT_CURLY_BRACE);
 
 
     /**
     /**
+     *    anyxml-stmt         = anyxml-keyword sep identifier-arg-str optsep
+     *                         (";" /
+     *                         "{" stmtsep
+     *                             ;; these stmts can appear in any order
+     *                             [when-stmt stmtsep]
+     *                             *(if-feature-stmt stmtsep)
+     *                             *(must-stmt stmtsep)
+     *                             [config-stmt stmtsep]
+     *                             [mandatory-stmt stmtsep]
+     *                             [status-stmt stmtsep]
+     *                             [description-stmt stmtsep]
+     *                             [reference-stmt stmtsep]
+     *                          "}")
+     */
+     anyxmlStatement : ANYXML_KEYWORD identifier (STMTEND | LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement
+                     | mustStatement | configStatement | mandatoryStatement | statusStatement | descriptionStatement
+                     | referenceStatement)* RIGHT_CURLY_BRACE);
+
+    /**
      *  uses-stmt           = uses-keyword sep identifier-ref-arg-str optsep
      *  uses-stmt           = uses-keyword sep identifier-ref-arg-str optsep
      *                        (";" /
      *                        (";" /
      *                         "{" stmtsep
      *                         "{" stmtsep
@@ -934,7 +967,7 @@ package org.onosproject.yangutils.parser.antlrgencode;
      * TODO : 0..1 occurance to be checked in listener
      * TODO : 0..1 occurance to be checked in listener
      */
      */
     usesStatement : USES_KEYWORD string (STMTEND | LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement | statusStatement
     usesStatement : USES_KEYWORD string (STMTEND | LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement | statusStatement
-                | descriptionStatement | referenceStatement | refineStatement | usesAugmentStatement)* RIGHT_CURLY_BRACE);
+                | descriptionStatement | referenceStatement | refineStatement | augmentStatement)* RIGHT_CURLY_BRACE);
 
 
     /**
     /**
      *  refine-stmt         = refine-keyword sep refine-arg-str optsep
      *  refine-stmt         = refine-keyword sep refine-arg-str optsep
@@ -951,7 +984,7 @@ package org.onosproject.yangutils.parser.antlrgencode;
      */
      */
     refineStatement : REFINE_KEYWORD refine (STMTEND  | LEFT_CURLY_BRACE (refineContainerStatements
     refineStatement : REFINE_KEYWORD refine (STMTEND  | LEFT_CURLY_BRACE (refineContainerStatements
                     | refineLeafStatements | refineLeafListStatements | refineListStatements | refineChoiceStatements
                     | refineLeafStatements | refineLeafListStatements | refineListStatements | refineChoiceStatements
-                    | refineCaseStatements) RIGHT_CURLY_BRACE);
+                    | refineCaseStatements | refineAnyxmlStatements) RIGHT_CURLY_BRACE);
 
 
     /**
     /**
      *  refine-container-stmts =
      *  refine-container-stmts =
@@ -1024,22 +1057,15 @@ package org.onosproject.yangutils.parser.antlrgencode;
     refineCaseStatements : (descriptionStatement | referenceStatement)? | (referenceStatement | descriptionStatement)?;
     refineCaseStatements : (descriptionStatement | referenceStatement)? | (referenceStatement | descriptionStatement)?;
 
 
     /**
     /**
-     *  uses-augment-stmt   = augment-keyword sep uses-augment-arg-str optsep
-     *                        "{" stmtsep
-     *                            ;; these stmts can appear in any order
-     *                            [when-stmt stmtsep]
-     *                            *(if-feature-stmt stmtsep)
-     *                            [status-stmt stmtsep]
-     *                            [description-stmt stmtsep]
-     *                            [reference-stmt stmtsep]
-     *                            1*((data-def-stmt stmtsep) /
-     *                               (case-stmt stmtsep))
-     *                         "}"
-     * TODO : 0..1 occurance to be checked in listener
+     *  refine-anyxml-stmts = ;; these stmts can appear in any order
+     *                        *(must-stmt stmtsep)
+     *                        [config-stmt stmtsep]
+     *                        [mandatory-stmt stmtsep]
+     *                        [description-stmt stmtsep]
+     *                        [reference-stmt stmtsep]
      */
      */
-    usesAugmentStatement : AUGMENT_KEYWORD augment LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement
-                         | statusStatement | descriptionStatement | referenceStatement | dataDefStatement
-                         | caseStatement)* RIGHT_CURLY_BRACE;
+     refineAnyxmlStatements : (mustStatement | configStatement | mandatoryStatement | descriptionStatement
+                            | referenceStatement)*;
 
 
     /**
     /**
      *  augment-stmt        = augment-keyword sep augment-arg-str optsep
      *  augment-stmt        = augment-keyword sep augment-arg-str optsep
@@ -1251,6 +1277,10 @@ package org.onosproject.yangutils.parser.antlrgencode;
 
 
     deviation : string;
     deviation : string;
 
 
+    value : string;
+
+    fraction : string;
+
     yangConstruct : ANYXML_KEYWORD | ARGUMENT_KEYWORD | AUGMENT_KEYWORD | BASE_KEYWORD | BELONGS_TO_KEYWORD
     yangConstruct : ANYXML_KEYWORD | ARGUMENT_KEYWORD | AUGMENT_KEYWORD | BASE_KEYWORD | BELONGS_TO_KEYWORD
                   | BIT_KEYWORD | CASE_KEYWORD | CHOICE_KEYWORD | CONFIG_KEYWORD | CONTACT_KEYWORD | CONTAINER_KEYWORD
                   | BIT_KEYWORD | CASE_KEYWORD | CHOICE_KEYWORD | CONFIG_KEYWORD | CONTACT_KEYWORD | CONTAINER_KEYWORD
                   | DEFAULT_KEYWORD | DESCRIPTION_KEYWORD | ENUM_KEYWORD ERROR_APP_TAG_KEYWORD | ERROR_MESSAGE_KEYWORD
                   | DEFAULT_KEYWORD | DESCRIPTION_KEYWORD | ENUM_KEYWORD ERROR_APP_TAG_KEYWORD | ERROR_MESSAGE_KEYWORD

+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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 at
+ *
+ *     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 org.onosproject.yangutils.parser.impl;
+
+import java.io.IOException;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+
+/**
+ * Test cases for testing tree walk listener functionality.
+ */
+public class TreeWalkListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+    /**
+     * Checks whether exception is thrown for ordered statement.
+     */
+    @Test
+    public void processOrderedByStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"ordered-by\" is not supported in current version, please check wiki" +
+                " for YANG utils road map.");
+        manager.getDataModel("src/test/resources/OrderedByStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown for anyxml statement.
+     */
+    @Test
+    public void processAnyXmlStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"anyxml\" is not supported.");
+        manager.getDataModel("src/test/resources/AnyxmlStatement.yang");
+    }
+}

@@ -134,9 +134,9 @@ public class ConfigListenerTest {
     @Test
     @Test
     public void processModuleSubStatementConfig() throws IOException, ParserException {
     public void processModuleSubStatementConfig() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'config' expecting {'augment', 'choice', 'contact', 'container',"
-                + " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include', "
-                + "'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+        thrown.expectMessage("mismatched input 'config' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementConfig.yang");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementConfig.yang");
     }
     }

+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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 at
+ *
+ *     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 org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangChoice;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing default listener functionality.
+ */
+public class DefaultListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if default value is set correctly.
+     */
+    @Test
+    public void processLeafSubStatementDefault() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafSubStatementDefault.yang");
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDefaultValueInString(), is("\"1\""));
+    }
+
+    /**
+     * Checks if default value is set correctly.
+     */
+    @Test
+    public void processChoiceSubStatementDefault() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceSubStatementDefault.yang");
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+        assertThat(yangChoice.getDefaultValueInString(), is("\"hello\""));
+    }
+}

@@ -18,7 +18,10 @@ package org.onosproject.yangutils.parser.impl.listeners;
 
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.Is.is;
 import static org.hamcrest.core.Is.is;
+
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.onosproject.yangutils.datamodel.YangDataTypes;
 import org.onosproject.yangutils.datamodel.YangDataTypes;
 import org.onosproject.yangutils.datamodel.YangEnum;
 import org.onosproject.yangutils.datamodel.YangEnum;
 import org.onosproject.yangutils.datamodel.YangEnumeration;
 import org.onosproject.yangutils.datamodel.YangEnumeration;
@@ -38,6 +41,9 @@ import java.util.Set;
  */
  */
 public class EnumListenerTest {
 public class EnumListenerTest {
 
 
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
     private final YangUtilsParserManager manager = new YangUtilsParserManager();
     private final YangUtilsParserManager manager = new YangUtilsParserManager();
 
 
     /**
     /**
@@ -84,7 +90,28 @@ public class EnumListenerTest {
      */
      */
     @Test(expected = ParserException.class)
     @Test(expected = ParserException.class)
     public void processEnumWithDuplicateName() throws IOException, ParserException {
     public void processEnumWithDuplicateName() throws IOException, ParserException {
-
         YangNode node = manager.getDataModel("src/test/resources/EnumWithDuplicateName.yang");
         YangNode node = manager.getDataModel("src/test/resources/EnumWithDuplicateName.yang");
     }
     }
+
+    /**
+     * Checks enum boundary value.
+     */
+    @Test
+    public void processEnumBoundaryValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : value value 21474836472147483647 is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/EnumBoundaryValue.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown if value is not specified following max enum value.
+     */
+    @Test
+    public void processEnumMaxNextValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : "
+                + "An enum value MUST be specified for enum substatements following the one"
+                + "with the current highest value");
+        YangNode node = manager.getDataModel("src/test/resources/EnumMaxNextValue.yang");
+    }
 }
 }

@@ -203,12 +203,32 @@ public class KeyListenerTest {
     }
     }
 
 
     /**
     /**
+     * Checks key values are set correctly.
+     */
+    @Test
+    public void processKeyWithUsesInList() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/KeyWithUsesInList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild().getNextSibling();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
      * Checks whether exception is thrown when key leaf identifier is not found in list.
      * Checks whether exception is thrown when key leaf identifier is not found in list.
      */
      */
     @Test
     @Test
     public void processInvalidLeafIdentifier() throws IOException, ParserException {
     public void processInvalidLeafIdentifier() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("Leaf identifier must refer to a child leaf of the list");
+        thrown.expectMessage("An identifier, in key, must refer to a child leaf of the list");
         YangNode node = manager.getDataModel("src/test/resources/InvalidLeafIdentifier.yang");
         YangNode node = manager.getDataModel("src/test/resources/InvalidLeafIdentifier.yang");
     }
     }
 
 
@@ -218,7 +238,7 @@ public class KeyListenerTest {
     @Test
     @Test
     public void processInvalidLeafListIdentifier() throws IOException, ParserException {
     public void processInvalidLeafListIdentifier() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("Leaf-list identifier must refer to a child leaf of the list");
+        thrown.expectMessage("An identifier, in key, must refer to a child leaf of the list");
         YangNode node = manager.getDataModel("src/test/resources/InvalidLeafListIdentifier.yang");
         YangNode node = manager.getDataModel("src/test/resources/InvalidLeafListIdentifier.yang");
     }
     }
 
 

@@ -94,9 +94,9 @@ public class LeafListListenerTest {
     @Test
     @Test
     public void processLeafListInvalidStatement() throws IOException, ParserException {
     public void processLeafListInvalidStatement() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'leaflist' expecting {'augment', 'choice', 'contact', 'container',"
-                + " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include',"
-                + " 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+        thrown.expectMessage("mismatched input 'leaflist' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
         YangNode node = manager.getDataModel("src/test/resources/LeafListInvalidStatement.yang");
         YangNode node = manager.getDataModel("src/test/resources/LeafListInvalidStatement.yang");
     }
     }

@@ -95,9 +95,9 @@ public class LeafListenerTest {
     @Test
     @Test
     public void processLeafInvalidStatement() throws IOException, ParserException {
     public void processLeafInvalidStatement() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'leafs' expecting {'augment', 'choice', 'contact', 'container',"
-                + " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include',"
-                + " 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+        thrown.expectMessage("mismatched input 'leafs' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
         YangNode node = manager.getDataModel("src/test/resources/LeafInvalidStatement.yang");
         YangNode node = manager.getDataModel("src/test/resources/LeafInvalidStatement.yang");
     }
     }

@@ -232,4 +232,39 @@ public class LengthRestrictionListenerTest {
                 " 18446744073709551615.");
                 " 18446744073709551615.");
         YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidInterval.yang");
         YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidInterval.yang");
     }
     }
+
+    /**
+     * Checks valid length substatements.
+     */
+    @Test
+    public void processLengthSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        assertThat(lengthRestriction.getDescription(), is("\"length description\""));
+        assertThat(lengthRestriction.getReference(), is("\"length reference\""));
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
 }
 }

@@ -148,9 +148,9 @@ public class MandatoryListenerTest {
     @Test
     @Test
     public void processModuleSubStatementMandatory() throws IOException, ParserException {
     public void processModuleSubStatementMandatory() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'mandatory' expecting {'augment', 'choice', 'contact', 'container',"
-                + " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include',"
-                + " 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+        thrown.expectMessage("mismatched input 'mandatory' expecting {'anyxml', 'augment', 'choice', 'contact',"
+                + " 'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
                 + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementMandatory.yang");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementMandatory.yang");
     }
     }

@@ -166,4 +166,32 @@ public class PatternRestrictionListenerTest {
                 .getPatternList().listIterator();
                 .getPatternList().listIterator();
         assertThat(patternListIterator.next(), is("-[0-9]+|[0-9]+"));
         assertThat(patternListIterator.next(), is("-[0-9]+|[0-9]+"));
     }
     }
+
+    /**
+     * Checks valid pattern substatement.
+     */
+    @Test
+    public void processPatternSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        assertThat(stringRestriction.getDescription(), is("\"pattern description\""));
+        assertThat(stringRestriction.getReference(), is("\"pattern reference\""));
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
 }
 }

@@ -174,4 +174,37 @@ public class RangeRestrictionListenerTest {
         thrown.expectMessage("YANG file error : Input value \"a\" is not a valid int32.");
         thrown.expectMessage("YANG file error : Input value \"a\" is not a valid int32.");
         YangNode node = manager.getDataModel("src/test/resources/RangeWithInvalidIntegerPattern.yang");
         YangNode node = manager.getDataModel("src/test/resources/RangeWithInvalidIntegerPattern.yang");
     }
     }
+
+    /**
+     * Checks valid range statement with description.
+     */
+    @Test
+    public void processRangeSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        assertThat(rangeRestriction.getDescription(), is("\"range description\""));
+        assertThat(rangeRestriction.getReference(), is("\"range reference\""));
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+    }
 }
 }

@@ -150,9 +150,9 @@ public class StatusListenerTest {
     @Test
     @Test
     public void processModuleSubStatementStatus() throws IOException, ParserException {
     public void processModuleSubStatementStatus() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'status' expecting {'augment', 'choice', 'contact', 'container', "
-                + "'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include',"
-                + " 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference', "
+        thrown.expectMessage("mismatched input 'status' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference', "
                 + "'revision', 'rpc', 'typedef', 'uses', '}'}");
                 + "'revision', 'rpc', 'typedef', 'uses', '}'}");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementStatus.yang");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementStatus.yang");
     }
     }

@@ -76,9 +76,9 @@ public class UnitsListenerTest {
     @Test
     @Test
     public void processModuleSubStatementUnits() throws IOException, ParserException {
     public void processModuleSubStatementUnits() throws IOException, ParserException {
         thrown.expect(ParserException.class);
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'type' expecting {'augment', 'choice', 'contact', 'container', "
-                + "'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', "
-                + "'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', "
+        thrown.expectMessage("mismatched input 'type' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity',"
+                + " 'import', 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', "
                 + "'reference', 'revision', 'rpc', 'typedef', 'uses', '}'}");
                 + "'reference', 'revision', 'rpc', 'typedef', 'uses', '}'}");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementUnits.yang");
         YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementUnits.yang");
     }
     }

@@ -80,6 +80,84 @@ public class ValueListenerTest {
     }
     }
 
 
     /**
     /**
+     * Checks explicitly configured negative value.
+     */
+    @Test
+    public void processValueStatementWithNegativeValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueStatementWithNegativeValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        Set<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(-2));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(-1));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(0));
+            }
+        }
+    }
+
+    /**
+     * Checks explicitly configured value with double quotes.
+     */
+    @Test
+    public void processValueStatementWithQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueStatementWithQuotes.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        Set<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(10));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(100));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(1000));
+            }
+        }
+    }
+
+    /**
      * Checks explicit value and auto generated value.
      * Checks explicit value and auto generated value.
      */
      */
     @Test
     @Test

@@ -26,6 +26,7 @@ import java.util.List;
 import org.junit.Rule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.plugin.manager.YangFileInfo;
 
 
 import static org.hamcrest.core.Is.is;
 import static org.hamcrest.core.Is.is;
 import static org.hamcrest.core.IsNot.not;
 import static org.hamcrest.core.IsNot.not;
@@ -135,7 +136,7 @@ public final class YangFileScannerTest {
 
 
         String emptyYangDir = baseDir + separator + "scanner1";
         String emptyYangDir = baseDir + separator + "scanner1";
         File path = createDirectory(emptyYangDir);
         File path = createDirectory(emptyYangDir);
-        List<String> emptyDirContents = getYangFiles(path.toString());
+        List<YangFileInfo> emptyDirContents = getYangFiles(path.toString());
         List<String> expectedContents = new LinkedList<>();
         List<String> expectedContents = new LinkedList<>();
         assertThat(true, is(emptyDirContents.equals(expectedContents)));
         assertThat(true, is(emptyDirContents.equals(expectedContents)));
     }
     }

+module event {
+
+    namespace "http://example.com/event";
+    prefix "ev";
+
+    notification event {
+        leaf event-class {
+            type string;
+        }
+        anyxml reporting-entity;
+        leaf severity {
+            type string;
+        }
+    }
+}
+

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container food {
+       choice snack {
+           case sports-arena {
+               leaf pretzel {
+                   type string;
+               }
+               leaf beer {
+                   type string;
+               }
+           }
+           case late-night {
+               leaf chocolate {
+                   type string;
+               }
+           }
+           default "hello";
+       }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf ifType {
+        type enumeration {
+             enum "unbounded";
+             enum ZERO;
+             enum two;
+             enum four;
+             enum seven {
+                 value 21474836472147483647;
+             }
+         }
+     }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf ifType {
+        type enumeration {
+             enum "unbounded";
+             enum ZERO;
+             enum two;
+             enum four;
+             enum seven {
+                 value 2147483647;
+             }
+             enum five;    
+            
+         }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    grouping network {
+        leaf invalid-interval {
+            type "string";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+    list valid {
+        key "invalid-interval";
+        leaf invalid {
+            type "string";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+        uses "network";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        default "1";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type string {
+            length "0..100" {
+                description "length description";
+                reference "length reference";
+            }
+         }
+    }
+}

+module rock {
+    namespace "http://example.net/rock";
+    prefix "rock";
+    leaf-list cipher  {
+         type string;
+         ordered-by user;
+         description "A list of ciphers";
+    }
+}
+

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type string {
+            pattern "[a-zA-Z]" {
+                description "pattern description";
+                reference "pattern reference";
+            }
+         }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type int32 {
+            range "1..4 | 10..20" {
+                description "range description";
+                reference "range reference";
+            }
+         }
+    }
+}
+

@@ -10,7 +10,6 @@ module Test {
              prefix "P";
              prefix "P";
          }
          }
     augment "/if:interfaces/if:ifEntry" {
     augment "/if:interfaces/if:ifEntry" {
-        when "if:ifType='ds0'";
         leaf ds0ChannelNumber {
         leaf ds0ChannelNumber {
             type P:ChannelNumber;
             type P:ChannelNumber;
         }
         }

@@ -14,9 +14,7 @@ module rock {
            type int32;
            type int32;
         }
         }
         leaf if-name {
         leaf if-name {
-           type leafref {
-               path "/interface/name";
-           }
+           type leafref;
         }
         }
         leaf if-admin-status {
         leaf if-admin-status {
            type P:admin-status;
            type P:admin-status;

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf speed {
+        type enumeration {
+          enum 10m {
+	     value -2;
+          }
+          enum 100m {
+	     value "-1";
+          }
+          enum auto {
+	     value 0;
+          }
+        }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf speed {
+        type enumeration {
+          enum 10m {
+	     value "10";
+          }
+          enum 100m {
+	     value "100";
+          }
+          enum auto {
+	     value "1000";
+          }
+        }
+    }
+}