    /*
     *  call-seq:
     *    phrase_query.add_term(term, position_increment = 1) -> phrase_query
     *    phrase_query << term -> phrase_query
     *
     *  Add a term to the phrase query. By default the position_increment is set
     *  to 1 so each term you add is expected to come directly after the previous
     *  term. By setting position_increment to 2 you are specifying that the term
     *  you just added should occur two terms after the previous term. For
     *  example;
     *
     *    phrase_query.add_term("big").add_term("house", 2)
     *    # matches => "big brick house"
     *    # matches => "big red house"
     *    # doesn't match => "big house"
     */
    static VALUE
    frb_phq_add(int argc, VALUE *argv, VALUE self)
    {
        VALUE rterm, rpos_inc;
        int pos_inc = 1;
        GET_Q();
        if (rb_scan_args(argc, argv, "11", &rterm, &rpos_inc) == 2) {
            pos_inc = FIX2INT(rpos_inc);
        }
        switch (TYPE(rterm)) {
            case T_STRING:
                {
                    phq_add_term(q, StringValuePtr(rterm), pos_inc);
                    break;
                }
            case T_ARRAY:
                {
                    int i;
                    char *t;
                    if (RARRAY_LEN(rterm) < 1) {
                        rb_raise(rb_eArgError, "Cannot add empty array to a "
                                 "PhraseQuery. You must add either a string or "
                                 "an array of strings");
                    }
                    t = StringValuePtr(RARRAY_PTR(rterm)[0]);
                    phq_add_term(q, t, pos_inc);
                    for (i = 1; i < RARRAY_LEN(rterm); i++) {
                        t = StringValuePtr(RARRAY_PTR(rterm)[i]);
                        phq_append_multi_term(q, t);
                    }
                    break;
                }
            default:
                rb_raise(rb_eArgError, "You can only add a string or an array of "
                         "strings to a PhraseQuery, not a %s\n",
                         rs2s(rb_obj_as_string(rterm)));
        }
        return self;
    }