/*
 *  call-seq:
 *     clause.to_s -> string
 *
 *  Return a string representation of this clause. This will not be used by
 *  BooleanQuery#to_s. It is only used by BooleanClause#to_s and will specify
 *  whether the clause is +:must+, +:should+ or +:must_not+.
 */
static VALUE
frt_bc_to_s(VALUE self)
{
    VALUE rstr;
    char *qstr, *ostr = "", *str;
    int len;
    GET_BC();
    qstr = bc->query->to_s(bc->query, "");
    switch (bc->occur) {
        case BC_SHOULD:
            ostr = "Should";
            break;
        case BC_MUST:
            ostr = "Must";
            break;
        case BC_MUST_NOT:
            ostr = "Must Not";
            break;
    }
    len = strlen(ostr) + strlen(qstr) + 2;
    str = ALLOC_N(char, len);
    sprintf(str, "%s:%s", ostr, qstr);
    rstr = rb_str_new(str, len);
    free(qstr);
    free(str);
    return rstr;
}