42      *  actually have any user data.  ANTLR v3 uses a list of children approach
44      *  an empty node whose children represent the list.  An empty, but
60          *  as there are no fields other than the children list, which cannot
61          *  be copied as the children are not considered part of this node. 
69          *  Get the children internal List; note that if you directly mess with
73         public virtual IList<ITree> Children  property in Antlr.Runtime.Tree.BaseTree
92                 if ( Children == null )
95                 return Children.Count;
174             if ( Children == null || i >= Children.Count )  in GetChild()
177             return Children[i];  in GetChild()
182             foreach ( ITree child in Children )  in GetFirstChildWithType()
194          *  Warning: if t has no children, but child does
195          *  and child isNil then this routine moves children to t via
196          *  t.children = child.children; i.e., without copying the array.
202             //System.out.println("existing children: "+children);  in AddChild()
209                 // t is an empty node possibly with children  in AddChild()
211 …           if ( childTree != null && this.Children != null && this.Children == childTree.Children )  in AddChild()
215                 // just add all of childTree's children to this  in AddChild()
218                     if ( this.Children != null || childTree == null )  in AddChild()
220                         if ( this.Children == null )  in AddChild()
221                             this.Children = CreateChildrenList();  in AddChild()
223                         // must copy, this has children already  in AddChild()
228                             this.Children.Add( c );  in AddChild()
231                             c.ChildIndex = Children.Count - 1;  in AddChild()
236                         // no children for this but t is a BaseTree with children;  in AddChild()
238                         this.Children = childTree.Children;  in AddChild()
245                 // child is not nil (don't care about children)  in AddChild()
246                 if ( Children == null )  in AddChild()
248                     Children = CreateChildrenList(); // create children list on demand  in AddChild()
250                 Children.Add( t );  in AddChild()
252                 t.ChildIndex = Children.Count - 1;  in AddChild()
254             // System.out.println("now children are: "+children);  in AddChild()
257         /** <summary>Add all elements of kids list as children of this node</summary> */
280             if ( Children == null )  in SetChild()
282                 Children = CreateChildrenList();  in SetChild()
284             Children[i] = t;  in SetChild()
289         /** Insert child t at child position i (0..n-1) by shifting children
306             Children.Insert(i, t);  in InsertChild()
320             if ( Children == null )  in DeleteChild()
323             ITree killed = Children[i];  in DeleteChild()
324             Children.RemoveAt( i );  in DeleteChild()
331          *  Delete children from start to stop and replace with t even if t is
332          *  a list (nil-root tree).  num of children can increase or decrease.
333          *  For huge child lists, inserting children can force walking rest of
334          *  children to set their childindex; could be slow.
353             if ( Children == null )  in ReplaceChildren()
355                 throw new ArgumentException( "indexes invalid; no children in list" );  in ReplaceChildren()
361             // normalize to a list of children to add: newChildren  in ReplaceChildren()
365                 if ( baseTree != null && baseTree.Children != null )  in ReplaceChildren()
367                     newChildren = baseTree.Children;  in ReplaceChildren()
388                 int j = 0; // index into new children  in ReplaceChildren()
392                     Children[i] = child;  in ReplaceChildren()
401                 // set children and then delete extra  in ReplaceChildren()
404                     Children[startChildIndex + j] = newChildren[j];  in ReplaceChildren()
410                     Children.RemoveAt( indexToDelete );  in ReplaceChildren()
417                 // fill in as many children as we can (replacingHowMany) w/o moving data  in ReplaceChildren()
420                     Children[startChildIndex + j] = newChildren[j];  in ReplaceChildren()
425                     Children.Insert( startChildIndex + j, newChildren[j] );  in ReplaceChildren()
432         /** <summary>Override in a subclass to change the impl of children list</summary> */
541             if ( Children == null || Children.Count == 0 )  in ToStringTree()
552             for ( int i = 0; Children != null && i < Children.Count; i++ )  in ToStringTree()
554                 ITree t = Children[i];  in ToStringTree()