zip

static VALUE
lazy_zip(int argc, VALUE *argv, VALUE obj)
{
    VALUE ary, v;
    long i;
    rb_block_call_func *func = lazy_zip_arrays_func;

    if (rb_block_given_p()) {
        return rb_call_super(argc, argv);
    }

    ary = rb_ary_new2(argc);
    for (i = 0; i < argc; i++) {
        v = rb_check_array_type(argv[i]);
        if (NIL_P(v)) {
            for (; i < argc; i++) {
                if (!rb_respond_to(argv[i], id_each)) {
                    rb_raise(rb_eTypeError, "wrong argument type %s (must respond to :each)",
                        rb_obj_classname(argv[i]));
                }
            }
            ary = rb_ary_new4(argc, argv);
            func = lazy_zip_func;
            break;
        }
        rb_ary_push(ary, v);
    }

    return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj,
                                         func, ary),
                           ary, lazy_receiver_size);
}