USING: accessors inverse kernel models models.arrow ; IN: models.illusion TUPLE: illusion < arrow ; : ( model quot -- illusion ) f illusion new-model swap >>quot over >>model [ add-dependency ] keep ; : ( model quot -- illusion ) dup activate-model ; : backtalk ( value object -- ) [ quot>> [undo] call( a -- b ) ] [ model>> ] bi set-model ; M: illusion update-model ( model -- ) [ [ value>> ] keep backtalk ] with-locked-model ;