Vim - inconsistency between :tabnext N and :tabprev N

Question

From Vim's :help tabs:

:tabp[revious] {count}
:tabN[ext] {count}
{count}<C-PageUp>
{count}gT   Go {count} tab pages back.  Wraps around from the first one
            to the last one.

While

:tabn[ext] {count}
{count}<C-PageDown>
{count}gt   Go to tab page {count}.  The first tab page has number one.

Finally, parameterless :tabn behaves consistent with :tabp and :tabp 1.

Why is that? Is it only to make 3gt jump to tab 3 instead of 3 tabs ahead? Nothing prevents vim from having :tabn 3 and :tabjump 3, and bind Ngt to use :tabjump rather than :tabn. Frankly, to me this looks like a design error.

Can we have :tabp N forward equivalent using only built-in commands? I noticed one can't use :tabprev -2, for example. If there is no built-in counterpart to :tabp N, then why have :tabp N at all?

Answer 1

Yes, this is inconsistent, but I also find the available choices convenient. It allows both for iterating back / forward one by one, as well as absolute addressing.

Why is it that way? You could search through the vim_dev mailing list archives for messages when this feature had been proposed / a patch submitted, or ask there if anyone remembers the background. (Note that there are many other features with less-than-optimal interfaces; it's a volunteer project with a single bottleneck BDFL at the top, and the worse is better mentality certainly applies here.)

To perform relative tab navigation in forward direction, you can use:

:execute 'tabnext' tabpagenr() + N

You can easily define a custom command or mapping if you find this useful.