When I execute:
:exe "normal! \<c-o>"
, it works as expected (it jumps to the previous cursor location).
But when I execute:
:exe "normal! \<c-i>"
, it outputs the E471 error:
E471: Argument required
Then I need to prepend with 1 to make it work:
:exe "normal! 1\<c-i>"
Is it a normal behaviour?
Please note I'm using vim-gtk (graphical).
Vim version : 7.4
Rustines : 1-1689
Yes I think it's a normal behavior.
In :help keycode, you can read that <C-I> and <Tab> have the same decimal keycode (9):
<Tab> tab CTRL-I 9 *tab* *Tab*
Which means that Vim and gVim can't make the difference between the two keys.
You can find a technical reason for this here.
So "\<C-I>" is translated into a literal tab character.
After the translation, Vim probably parses the tab as a syntax character separating a command from its arguments (here :normal from {commands}) ; like a space.
Since there's nothing after your tab, Vim doesn't pass anything to :normal, and the latter complains with the error E471: Argument required.
The solution is given in :help :normal:
{commands} cannot start with a space. Put a count of
1 (one) before it, "1 " is one space.
You have to prefix the {commands} with 1 when they begin with a space (and probably with a tab).
Hitting 1 then Ctrl-I in normal mode has the same effect as hitting Ctrl-I alone.
But here on the command-line, by prefixing <C-I> with a count, you prevent Vim from parsing it as a syntax character, but rather as a part of the argument {commands}.
