/*
 *  call-seq:
 *     query.add(span_query) -> self
 *     query << span_query -> self
 *
 *  Add a clause to the SpanNearQuery. Clauses are stored in the order they
 *  are added to the query which is important for matching. Note that clauses
 *  must be SpanQueries, not other types of query.
 */
static VALUE
frt_spannq_add(VALUE self, VALUE rclause)
{
    GET_Q();
    Query *clause;
    Data_Get_Struct(rclause, Query, clause);
    spannq_add_clause(q, clause);
    return self;
}