-- a LIST is a collection with fixed order.
-- Elements can occur any number of times.
-- Time complexity for data adding is O(1).
-- Time complexity for data searching is O(n).
-- Space complexity is O(n).

indexing

  names: list, chain;
  contents: generic;

  author: "Guichard Damien";
  created: 9,November,1995;
  modified: 9,November,1995

class LIST inherit BAG
  redefine add
  end
feature
  add (element:BAG) is
    -- Add an element to the list.
    do
      if next = Void then next := element end
      if last /= Void then last.set_next(element)
      last := element
    end -- add
  item (i:INTEGER):BAG is
    -- Find i-th list item (from 1).
    require -- i > 0
    local n:INTEGER
    do
      from Result := Current
      until n = i or Result = Void
      variant -- i - n
      loop
        Result := Result.next
        n := n + 1
      end
    end -- item
feature{NONE}
  last:BAG
end -- class 'LIST'