359   def set_child( index, tree )  argument
360     return if tree.nil?
361     tree.flat_list? and raise ArgumentError, "Can't set single child to a list"
362     tree.parent = self
363     tree.child_index = index
364     self[ index ] = tree
690   def add_child( tree, child )  argument
691     tree.add_child( child ) if tree and child
694   def child_count( tree )  argument
695     tree.child_count
698   def child_index( tree )  argument
699     tree.child_index rescue 0
702   def child_of( tree, index )  argument
703     tree.nil? ? nil : tree.child( index )
710   def copy_tree( tree, parent = nil )  argument
711     tree or return nil
712     new_tree = copy_node( tree )
713     set_child_index( new_tree, child_index( tree ) )
715     each_child( tree ) do | child |
722   def delete_child( tree, index )  argument
723     tree.delete_child( index )
727   def each_child( tree )  argument
728     block_given? or return enum_for( :each_child, tree )
729     for i in 0 ... child_count( tree )
730       yield( child_of( tree, i ) )
732     return tree
735   def each_ancestor( tree, include_tree = true )  argument
736     block_given? or return enum_for( :each_ancestor, tree, include_tree )
738       begin yield( tree ) end while tree = parent_of( tree )
740       while tree = parent_of( tree ) do yield( tree ) end
744   def flat_list?( tree )  argument
745     tree.flat_list?
748   def empty?( tree )  argument
749     child_count( tree ).zero?
752   def parent( tree )  argument
753     tree.parent
771   def set_child_index( tree, index )  argument
772     tree.child_index = index
775   def set_parent( tree, parent )  argument
776     tree.parent = parent
779   def set_token_boundaries( tree, start_token = nil, stop_token = nil )  argument
780     return unless tree
784     tree.start_index = start
785     tree.stop_index = stop
786     return tree
789   def text_of( tree )  argument
790     tree.text rescue nil
793   def token( tree )  argument
794     CommonTree === tree ? tree.token : nil
797   def token_start_index( tree )  argument
798     tree ? tree.token_start_index : -1
801   def token_stop_index( tree )  argument
802     tree ? tree.token_stop_index : -1
805   def type_name( tree )  argument
806     tree.name rescue 'INVALID'
809   def type_of( tree )  argument
810     tree.type rescue INVALID_TOKEN_TYPE
862     tree = create_with_payload( from_token )
863     return tree
913   def empty?( tree )  argument
914     tree.empty?
917   def each_child( tree )  argument
918     block_given? or return enum_for( :each_child, tree )
919     tree.each do | child |
1020   def fill_buffer( tree = @root )  argument
1021     @nodes << tree unless nil_tree = @adaptor.flat_list?( tree )
1022     unless @adaptor.empty?( tree )
1024       @adaptor.each_child( tree ) { | c | fill_buffer( c ) }
1027     @position = 0 if tree == @root