/*
 *  call-seq:
 *     explanation.score -> float
 *
 *  Returns the score represented by the query. This can be used for debugging
 *  purposes mainly to check that the score returned by the explanation
 *  matches that of the score for the document in the original query.
 */
static VALUE
frt_expl_score(VALUE self)
{
    GET_EXPL();
    return rb_float_new((double)expl->value);
}