Indenting comments to match code in vim

Question

I do all my coding in vim and am quite happy with it (so, please, no "use a different editor" responses), but have an ongoing annoyance in that the smartindent feature wants to not indent comments beginning with # at all. e.g., I want

  # Do something
  $x = $x + 1;
  if ($y) {
    # Do something else
    $y = $y + $z;
  }

instead of vim's preferred

# Do something
  $x = $x + 1;
  if ($y) {
# Do something else
    $y = $y + $z;
  }

The only ways I have been able to prevent comments from being sent to the start of the line are to either insert and delete a character on the line before hitting # (a nuisance to have to remember to do every time) or turn off smartindent entirely (losing automatic indentation increase/decrease as I open/close braces).

How can I set vim to maintain my indentation for comments instead of sending them to the start of the line?

Answer 1

I think "smartindent" is designed for C, so it thinks "#" is the start of a pre-processor directive instead of a comment. I don't know a solution for it, except if you type a space, then a backspace, then the "#" it won't do that.

Answer 2

This problem can be solved by putting the following in your _vimrc file.

set cindent
set cinkeys=0{,0},!^F,o,O,e " default is: 0{,0},0),:,0#,!^F,o,O,e

More info...

Answer 3

It looks like you're coding in Perl. Ensure that the following are set in your .vimrc:

filetype plugin indent on
syntax enable

These will tell Vim to set the filetype when opening a buffer and configure the indentation and syntax highlighting. No need to explicitly set smartindent since Vim's included Perl syntax file will set it (and any other Perl-specific customizations) automatically.

Answer 4

If you are using the "smartindent" indenting option, a fix for your problem is explained in the ":help smartindent" VIM documentation:

When typing '#' as the first character in a new line, the indent for that line is removed, the '#' is put in the first column. The indent is restored for the next line. If you don't want this, use this mapping: ":inoremap # X^H#", where ^H is entered with CTRL-V CTRL-H. When using the ">>" command, lines starting with '#' are not shifted right.

I use "smartindent" and can confirm that the fix described works for me. It tricks VIM by replacing the keystroke for "#" with typing "X", then hitting backspace, then typing "#" again. You can try this yourself manually and see that it does not trigger the auto-outdenting.