Advanced Usage of Ranges with Vim Keymappings - vim

I have a mapping in my vimrc that downwardly comments out regions of c code:
nmap comc :normal! I//<ESC>
Since the 'normal' ex command implicitly converts input such as "Ncomc" to ".,.+N-1 comc", I can range comments downwardly without many keystrokes and without leaving normal mode. This is, however, a very limited subset of what vim ranges can do. If I'm willing to be verbose, I can achieve upward ranging comments like so:
.,.-5 normal comc
While editing text, I would much prefer to type something like "-6comc" or make a mapping of "Comc" that uses upward ranges. I'm haven't been able to do so successfully.
Similarly, range operations support commenting until a search pattern is reached, e.g :
.,/int main/ comc
I would, however, like to do so without all that typing.

The behavior you requested is normally done with :h map-operator mapping. With this commenting 3 lines down will turn into comc2j though, but 3 lines up is now just as easy: comc2k.
You can also use visual mode without changing your mapping at all: V2kcomc. You will have to add xnoremap with the identical lhs and rhs because nnoremap works only for normal mode. (And do not use nmap.)
Third option is mapping - to something that moves {count} lines up and puts count back:
nnoremap <expr> - (v:count ? ":\<C-u>\n" . (v:count-1) . 'k' . v:count : '')
. This assumes you are writing 6-comc, not -6comc.
// By the way, I would suggest The NERD Commenter if it comes to the plugin.

While it's commendable to go as far as possible without any plugins, sometimes they're just the best option. What will you do when you start working in a language that has comments with # or (*...*)? Add new mappings for these comment characters?
I recommend commentary.vim which does filetype-aware commenting.
The default commenting operator in commentary.vim is gc. You can combine it with motions, and use it in Visual mode too.
Your use cases:
Comment downwards N lines (say, 3): :.,.+3normal gcc, or gc3j or 4gcc.
Comment upwards 5 lines: :.,.-5normal gcc, or simply gc5k.
Comment until int main: :.,/int main/-1normal gcc, or simply gc/int main followed by Enter.

Related

Vim function to find pattern, replace, and visual mode

So I use Vim to write reports at work, reports are basically a bunch of "common issues" that we write over and over, so they are templated. These templates have placeholder blocks {==BLOCK==} to ensure people modify things as/when needed, so this is an example:
The test revealed that it was possible to access {==sensitive data==},
as shown in the examples below...
That block may need to be modified, or not. So the idea is, I am editing the common issue, and I see there are 3 or 4 blocks like the one in the example, I'd like to press let's say [leader]b and then end up having the template text for the first block selected in visual mode without the {== and ==} that are around it.
I have tried a few things but I didn't get too far, any suggestions?
Thanks!
You could define the following function:
function! VisualSelect()
call search("==}")
norm hvT=
endfunction
nnoremap <leader>b :call VisualSelect()<cr>
vnoremap <leader>b Ol<esc>:call VisualSelect()<cr>
This will visually select the contents between {== and ==}. Typing <leader>b repeatedly will select the next occurrence.
Most template/snippet expand plugins support this.
With my lh-brackets plugin, you can execute
:SetMarkers {== ==}
and then jump from one placeholder to the next with CTRL+J with vim, or META-DEL with gvim. lh-brackets doesn't take care of loading/expanding templates. mu-template will add this layer.
If instead you choose to use one of the more popular snippet plugin, there will certainly be an option to change the syntax of the placeholders, but I don't know it.
The poor man's solution would look like:
nnoremap <c-j> <c-\><c-n>/{==.*==}<cr>v/==}/e<cr><c-g>
snoremap <c-j> <c-\><c-n>/{==.*==}<cr>v/==}/e<cr><c-g>
but it won't take care of restoring the search pattern, of the cases where the cursor is already within a placeholder, and so on...
EDIT: the version that automatically deletes the placeholder marks is
nnoremap <c-j> <c-\><c-n>/{==.*==}<cr>v/==}/e<cr>s<c-r>=matchstr(#", '{==\zs.*\ze==}')<cr><esc>gv6h<c-g>
the same in snoremap
In short:
nnoremap <leader>b /{==.*==}<cr>xxxvt=<esc>/==}<cr>xxxgv
What it does:
1.) find the pattern
/{==.*==}<cr>
2.) Remove the first "{=="
xxx
3.) Visual select your text until the first = (maybe this could be also optimized for using a regex instead of simple searching for the next =)
vt=
4.) Go to the end sequence
/==}<cr>
5.) Remove it
xxx
6.) Select again your last selection
gv
I have figured out a way based on what #snap said, I ended up adding the code to a Python plugin to run it through it, as that fits better with what I am trying to do, snippet below:
#neovim.command('VimisEditTemplateBlock')
def urlify(self):
"""Search next codify block and prepare for editing"""
[...]
self.nvim.command('call search("{==")') # Find beginning of codify block
self.nvim.command('norm xxx') # Delete {==
self.nvim.command('norm vf=') # Select the inner text
self.nvim.command('norm v')
self.nvim.command('norm xxxgvh') #Delete ==} and leave the inner text selected in Visual Mode

Delete specific lines above current line in vim normal mode? [duplicate]

I have a mapping in my vimrc that downwardly comments out regions of c code:
nmap comc :normal! I//<ESC>
Since the 'normal' ex command implicitly converts input such as "Ncomc" to ".,.+N-1 comc", I can range comments downwardly without many keystrokes and without leaving normal mode. This is, however, a very limited subset of what vim ranges can do. If I'm willing to be verbose, I can achieve upward ranging comments like so:
.,.-5 normal comc
While editing text, I would much prefer to type something like "-6comc" or make a mapping of "Comc" that uses upward ranges. I'm haven't been able to do so successfully.
Similarly, range operations support commenting until a search pattern is reached, e.g :
.,/int main/ comc
I would, however, like to do so without all that typing.
The behavior you requested is normally done with :h map-operator mapping. With this commenting 3 lines down will turn into comc2j though, but 3 lines up is now just as easy: comc2k.
You can also use visual mode without changing your mapping at all: V2kcomc. You will have to add xnoremap with the identical lhs and rhs because nnoremap works only for normal mode. (And do not use nmap.)
Third option is mapping - to something that moves {count} lines up and puts count back:
nnoremap <expr> - (v:count ? ":\<C-u>\n" . (v:count-1) . 'k' . v:count : '')
. This assumes you are writing 6-comc, not -6comc.
// By the way, I would suggest The NERD Commenter if it comes to the plugin.
While it's commendable to go as far as possible without any plugins, sometimes they're just the best option. What will you do when you start working in a language that has comments with # or (*...*)? Add new mappings for these comment characters?
I recommend commentary.vim which does filetype-aware commenting.
The default commenting operator in commentary.vim is gc. You can combine it with motions, and use it in Visual mode too.
Your use cases:
Comment downwards N lines (say, 3): :.,.+3normal gcc, or gc3j or 4gcc.
Comment upwards 5 lines: :.,.-5normal gcc, or simply gc5k.
Comment until int main: :.,/int main/-1normal gcc, or simply gc/int main followed by Enter.

Insert character without entering insert mode?

Sometimes I want to insert a # to comment out a line and test it quickly. Currently I do:
i#ESC:w
Is there something shorter I can do?
Although I agree with others that there are better ways to comment and uncomment code, it seems that people have gotten distracted and forgotten to actually answer the question.
This is my approach to inserting a single character:
:noremap <key> i <Esc>r
I tend to find that I need to replace, remove, or add single characters very often if I'm correcting typos, so (resp.) r, x, and whatever is chosen for <key> in the above become very handy.
Note that . is also particularly handy for this sort of task. It repeats the previous action.
Personally though, I only map this function to a valuable key when I'm doing a task where I use it frequently enough to justify occupying a prime spot on the keyboard (such as correcting typos), because really, it only saves one keystroke per use and that's only when <key> is not a combination, which of course limits availability.
I map a couple of things to my <leader> key (\ by default):
" # comment the current line
nnoremap <leader>d I#<ESC>
" block comment in visual mode
vnoremap <leader>c <ESC>'<O/*<ESC>'>o*/<ESC>V'<k
If you want to add a # to the start of a group of lines, then do this:
<ctl-v>
j (as many times as necessary
I#
<esc>
You could use a recording. From normal mode, type:
qlml0i#<press escape>`lq
Then to comment out a line, just press #l
Mapping in vim is so easy that I might do something like
:nmap CC I#<Esc>:w<CR>
on the fly. If I get used to it, then I will add it to my vimrc file.
:help key-mapping
:help usr_40.txt
Actually there is a plugin you might wanna take a look at:
http://www.vim.org/scripts/script.php?script_id=1218
It is specifically designed for that purpose.
I'm particularly fond of the tComment plugin. gcc to comment a line, repeat to uncomment, multiple lines, motions, etc.

Swap two characters atomically, so that it can be repeated with "."

The idiom for swapping two characters in Vim is xp.
See the help at :h 04.5, final paragraph, and Vim: how do I swap two characters?.
But very occasionally I need to do two or more swap operations in a row. I'm often surprised that what feels like a single operation to me, xp, is actually two operations to Vim. This makes it impossible to repeat xp with .. (Or atomic undo with u.)
Is there a way to swap two characters in a single operation that I can quickly repeat with .?
This isn't ideal, but if you store xp as a macro, it will be repeatable after you've executed the macro. So instead of xp, you're using, say #s (for swap). Then ## will repeat it. Not as nice as ., but it does work.
Edit: You know, I'm sure there's a way to accomplish this with some vimscript and tpope's repeat.vim. Sadly, my vimscript is not up to snuff. I got this far - maybe someone can correct where I'm going wrong?
fun! DoSwap()
:normal xp
silent! call repeat#set("\<Plug>Swap",1)
endfun
nnoremap <silent> <Plug>Swap :call DoSwap()<CR>
nmap <Leader>s <Plug>Swap
The problem with this is that once you enter \s, it does indeed swap the characters you're on, and it DOES repeat when you hit ., but it jumps to the beginning of the line first, which is not what you want. But I do think this can be done, I'm just not all the way there.
Here's an idea. Suppose the cursor is on the "y" of the word "oyxgen".
In normal mode, type
2sxy<Esc>
Now the word reads "oxygen". Find the next instance of the typo (fy) and repeat the change (.).
Too bad this works only for the specific swap "yx" to "xy", so this isn't the definitive solution.
Vimcasts.org has published an episode that addresses this very problem.
As #Jeremy guessed the solution is to use the repeat.vim plugin. Then simply add the following <Plug> mapping and key mapping to your vimrc.
nnoremap <silent> <Plug>Transpose xp:call repeat#set("\<Plug>Transpose")<CR>
nmap cp <Plug>Transpose
The mapping shown here uses cp. cp is the new xp, repeatable with . but otherwise exactly the same.
Now all that remains is getting used to it.

mapping # in vim

In my .vimrc I have mapped the #-key to a macro for commenting out/in lines of code.
Unfortunately # in vim already has a function - it searches backwards for the word beneath the cursor.
What I would now like to have is a way to map this functionality to another key-sequence (ideally I would like to have Control-* for that as * alone searches forward).
Does anyone know how to achieve this?
Many thanks!
Unfortunately, Ctrl + * cannot be used; I would propose \*; it's longer to type, but backwards searches are probably not that common.
:nnoremap <Leader>* #
Like Ingo Karkat said, mapping Ctrl+certain keys is impossible in vim. However, you can map Alt+8 instead:
noremap <A-8> #
I suggest Alt+8 instead of Alt+* because if you wanted to bend your hand in unnatural ways to press more than one modifier keys to perform a command, you would probably be using Emacs instead of Vim.
I use \+c for commenting and \+d for removing comments. The mappings are following :
:map \c <ESC>:s,^\(\s*\)[^/ \t]\#=,\1// <ESC>,e<CR>j$a
:map \d <ESC>:s,^\(\s*\)// \s\#!,\1<ESC>,e<CR>j$a
Above mappings are used in command mode. Taken from one answer on SO, which I am currently unable to find.

Resources