Indent guides that span empty lines.

1. Set g:leadmultispace to your indent guide characters – without escaping spaces. For example:

   let g:leadmultispace = '  ⋮ · ⋮ · ⋮ · ⋮ · ⋮ · ⋮ · ⋮ · ⋮'

   (Don't set 'listchars+=leadmultispace:...'. The plugin manages it for you.)

2. Set up a map to toggle your indent guides. For example:

   nmap <Leader>ti <Plug>(InterdentalToggle)

3. Set the filetypes for which you want indent guides by default. For example:

   autocmd FileType ruby,html call interdental#toggle(1)

The built-in option 'lcs-leadmultispace' is perfect for indent guides. It is one or more characters that are shown cyclically when a line has leading spaces.

For example, I like:

• indent guides every two characters;
• alternating two different characters to help distinguish the guides;
• not having a guide in column 1.

This is how to set it up. Note that spaces have to be escaped.

setlocal listchars+=leadmultispace:\ \ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮

And here is what it looks like:

The problem is that empty lines don't have any leading spaces, so they don't get indent guides.

This plugin uses virtual text to display the indent guides on empty lines.

- setlocal listchars+=leadmultispace:\ \ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮\ ·\ ⋮
+ let g:leadmultispace = '  ⋮ · ⋮ · ⋮ · ⋮ · ⋮ · ⋮ · ⋮ · ⋮'

Behold the unbroken indent guides!

Copyright Andrew Stewart, AirBlade Software Ltd. Released under the MIT licence.