def decompose( i )
      if typecode < Composite
        Lookup.new @p.decompose( i ), @index, @stride * typecode.num_elements
      else
        Lookup.new @p.decompose( i ), @index, @stride
      end
    end
def decompose( i )
      if typecode < Composite
        Lookup.new @p.decompose( i ), @index, @stride * typecode.num_elements
      else
        Lookup.new @p.decompose( i ), @index, @stride
      end
    end
Decompose composite elements

 This method decomposes composite elements into array.

 @return [Node] Result of decomposition.