public interface QueryTranslator
Convert the search expression provided by the user into the search
engine's native format. This way it is possible to have several
translators for each search engine, and it would be possible for
integrators to write their own. Also the databases have more
features than is currently used. To take advantage of these
features would just require to write a new QueryTranslator. The
default translator should be +/- words (aka AltaVista syntax)
commonly used by search engines on the web.