-- Demostration program for generic set handling package.

    WITH text_io ; USE text_io ; -- make text I/O package available
    WITH set_handler ; -- make generic set handling package available

    PROCEDURE setdemo IS

-- Global Types :

    TYPE colour IS ( violet, blue, white, green, yellow, orange, red ) ;

-- Generic Package Instantiation :

    PACKAGE colset IS NEW set_handler ( colour ) ;
    USE colset ;

-- Global Variables :

    colour_set    : set := full_set ; -- full set of colours
    colour_choice : set ;
    leftovers     : set ;
    one_colour    : colour ;

    BEGIN -- setdemo

-- set up colour_choice
    colour_choice := new_set ( ( red, white, blue ) ) ;

-- set up leftovers
    leftovers := colour_set - colour_choice ;

-- perform a couple of trivial tests
    IF leftovers <= colour_set THEN
       PUT ( "leftovers is a sub-set of colour_set" ) ; NEW_LINE ;
    END IF ;

    IF NOT set_is_empty ( colour_choice ) THEN
       PUT ( "colour_choice is not empty" ) ; NEW_LINE ;
    END IF ;

    one_colour := yellow ;
    IF one_colour <= new_set ( ( blue, yellow, white, orange ) ) THEN
       PUT ( "One colour test succeeds." ) ; NEW_LINE ;
    END IF ;

-- try to assign values directly to a set
-- this should generate an error at compile time
    leftovers := ( OTHERS => TRUE ) ;

    END setdemo ; ------------------------------------------------------