-----------------------------------------------------------------------------
-- PACKAGE BODY:
--      Abstract_Sets
-- AUTHOR:
--      Yoav Tzruya
-- IMPLEMENTATION NOTES:
--      - the to_string function turns an element into a string using
--        the unbounded string type.
----------------------------------------------------------------------------

-- ** BODY IMPORTS **
with Ada.Strings.Unbounded;

package body abstract_sets
is
                       
    function to_string (
                 set_arg : in    set'class)
            return string
    is
        copied_set : set'class := set_arg;
        str        : Ada.Strings.Unbounded.Unbounded_String :=
                        Ada.Strings.Unbounded.Null_Unbounded_String;
        elem       : set_element;

        use Ada.Strings.Unbounded; -- to enable operator visibilty , in order
                                   -- to clarify program. 
    begin  -- to_string
        str := str & "{";

        while true
        loop
            Take(
                from    => copied_set,
                element => elem);

            str := str & to_string(elem);
        end loop;

        return ""; -- just to acoid warning about program error

    exception
        when set_is_empty_exception =>
           str := str & "}";
           return Ada.Strings.Unbounded.To_String(str);
    end to_string;

end abstract_sets;