deferred class interface P_SEARCHABLE[G,K]

feature(s) from P_CONTAINER
   --  Status

   count: INTEGER
      --  Number of items in the container.

      ensure
         positive: Result >= 0

   is_empty: BOOLEAN
      --  Is the container empty?


   is_readable: BOOLEAN
      --  Is the container currently readable?


   is_writable: BOOLEAN
      --  Is the container currently writable?


   item: G
      --  Current item.

      require
         readable: is_readable;
         not_empty: not is_empty

feature(s) from P_CONTAINER
   --  Update

   reset
      --  Remove all objects from the container.

      require
         writable: is_writable
      ensure
         done: is_empty

feature(s) from P_CONTAINER
   --  Output

   out: STRING
      --  String representation.

      ensure
         is_copy:  --  new string

feature(s) from P_CONTAINER
   --  Utility

   is_void (x: ANY): BOOLEAN
      --  Void assertion for generic parameters.


feature(s) from P_SEARCHABLE
   --  Search

   search (x: K)
      --  Search 'x' in the container, and set the current item
      --  to one of the container's item which is equal to 'x' if 
      --  successful. Equality as per is_equal.

      require
         readable: is_readable

   found: BOOLEAN
      --  Result of the last search operation.


   found_count: INTEGER
      --  Number of items found during the last search.

      require
         meaningful: found = true
      ensure
         meaningful: Result >= 1

invariant
   empty: is_empty = count = 0;

end of deferred P_SEARCHABLE[G,K]