'Returns terms starting with the given exact prefix.
Type prefixes are recognized, but no other name munging is done.'

def prefix_lookup(self, prefix, valid_types=[]):

    (prefix, merged_valid_types, type_term) = self._apply_valid_types(prefix, valid_types)
    query = whoosh.query.Prefix(u'name', self.normalize_name(prefix))
    if type_term:
        query = (query & type_term)
    locale = self._get_current_locale()
    searcher = self.index.searcher()
    facet = LanguageFacet(locale.identifier)
    results = searcher.search(query, sortedby=facet)
    return self._whoosh_records_to_results(results)
