What's the most elegant way of commenting / uncommenting blocks of ruby code in Vim?

Question

In VIM, at the moment when I need to comment out a section of Ruby code:

• I navigate to the first column in the row I want to comment out
• I press CTRL-v t

Answer 1

I use these plugins:

1. vim-commentary by Tim Pope, which defines a comment operator gc
2. vim-textobj-rubyblock, which defines ir (inside Ruby block) and ar (around Ruby block) for Ruby do ... blocks.
3. vim-ruby which defines im/am for inside/around Ruby method, and iM/aM for inside/around Ruby class.

Using this combination, I can easily comment/uncomment Ruby-specific code in Normal mode, e.g.:

1. gcir / gcar comment inside/around Ruby do/end block.
2. gcim / gcam comment inside/around Ruby method.
3. gciM / gcaM comment inside/around Ruby class.
4. Plus normal Commentary maps like gcc to comment a line, or 5gcc to comment 5 lines.

All in all it's very Vim-like and natural.

Hope that helps.

Answer 2

After visually selecting, in block mode, the text you want to comment out, hit I (that is a capital i), type # and finally hit the escape key. It's basically the same procedure you are using currently, but using insert instead of replace.

Answer 3

I like using the following:

• put cursor on the first line you want to comment out
• enter ma (no colon) to put a marker on that line
• go to the last line of the block you want to comment out
• enter :'a,.s/^/#/ and then enter

That says, from the line containing marker "a", up to the current line, substitute a hash for the beginning of the line.

Answer 4

For each language (ftplugin), I write mappings which will add or remove the comment leader and move the cursor down one line. For example, in my python ftplugin, I have this:

noremap   <buffer> K      :s,^\(\s*\)[^# \t]\@=,\1#,e<CR>:nohls<CR>zvj
noremap   <buffer> <C-K>  :s,^\(\s*\)#\s\@!,\1,e<CR>:nohls<CR>zvj

I find this to be an extremely flexible setup:

• Hit K to comment the current line.
• Hit K repeatedly to comment lots of lines.
• 6K to comment 6 lines.
• K in visual mode comments the whole selection.
• Everything can be uncommented in the same way using CTRL-K
• If lines are already commented, they won't have an additional # added to the start.
• If a # is followed by a space, it is considered a text comment and doesn't get touched.

I adapt this slightly for each language. It doesn't work as well for Old C comments (/*...*/) but I prefer not to use those anyway.