noremap <C-j> to {

Question

Because I'm on a german keyboard layout { and } are relatively hard to type.

As a workaround especially for latex I used inoremap <C-j> { and inoremap <C-l> } which works great. After internalizing these I also tried to use them in all other modes via noremap <C-j> { e.g. such that /<C-j> would search for { and ci<C-j> change in curly braces, but this doesn't work.

I also tried onoremap and lnoremap which both failed. But it does work in normal mode i.e. <C-j> moves a paragraph backward.

As far as I understand / and c should both go into "operator-pending" mode, so that map and omap should both work. I also couldn't find information that <C-j> is "special" like <C-h>, and I guess in that case imap shouldn't work either. Am I overlooking something?

I tested this on vim 7.4 with an empty config.

Answer 1

/<C-j>

/ doesn't enter operator-pending mode, it enters command-line mode.

For this, you want noremap! which applies to insert mode and command-line mode.

:help map-modes does imply that your attempt of lnoremap should have worked, but :help language-mapping, a bit further down in the file, explains why this is not the case:

Generally: Whenever a character is to be typed that is part of the text in the buffer, not a Vim command character.

[...]

[Language mappings] are only used for typed characters.

:help i_CTRL-j links to the insert-mode documentation's "Special keys" section: Ctrl-J is not a character which gets inserted into the buffer, but instead is a control character that tells Vim to begin a new line^*.

ci<C-j>

c does enter operator pending mode, and you will find after having run onoremap <C-j> { as you describe, that c<c-j> works as expected.

The problem is ci{ works differently to how you are imagining. In this command the two keystrokes i{ are a text object (:help text-objects), and operator-pending mode maps don't apply in the middle of text objects. I think the fix for these will require a bit more verbosity:

onoremap i<c-j> i{
onoremap a<c-j> a{
" etc.

_{* If you're thinking that this is just a roundabout way of saying that a LF character is inserted when you type one, consider how Vim will save different bytes into the file depending on the current value of 'fileformat' — it's a subtle distinction, I agree.}