USING: kernel locals math sequences ;
IN: bubble-sort

:: swap ( i j seq -- )
    i seq nth
    j seq nth i seq set-nth
    j seq set-nth ;
: ?swap ( i j seq -- swapped? )
    3dup [ nth ] curry bi@ > [ swap t ] [ 3drop f ] if ;
: ?swap-with-next ( i seq -- swapped? )
    [ dup 1 + ] [ ?swap ] bi* ;
: (sort) ( seq -- swapped? )
    [ length 1 - iota ] keep
    [ ?swap-with-next ] curry [ or ] map-reduce ;
: bubble-sort ( seq -- sorted-seq )
    dup [ (sort) ] curry loop ;