Tabs, stop! The truth about tab and spaces in Vim

I’m one of those Jurassic reptiles that enjoys using Vim; don’t ask, just let me be and in case you feel like spending a weekend with me and my pack of laser-eyed tamed T-Rex’s playing with keyboard shortcuts just have a look at the ad-hoc collection of resources I collected over time and/or at my vimrc settings.

Now Vim, being a neat piece of software developed by smart people, has no less than 4 settings related to code indentation with pretty similar names just to make things easier; so far I managed surviving by teaching to the aforementioned T-Rex collective to leave comments in my vimrc to remind me why each of those 4 settings in being used, until I realized moving that arcane knowledge to a more reliable destination was a better idea, hence this post.

Bear with me if you want to learn everything about the magic world of indentation in Vim!

We’ll walk through each setting connected to indentation in detail to understand what each does and how it works together with his siblings.

tabstop

This setting tells Vim how many columns a tab should be made up of in the editor view, it takes care only of how tabs will be rendered and has no effect on the actual text.

expandtab and noexpandtab

Enabling this option via the set command will insert the appropriate number of spaces when in insert mode.

shiftwidth

Set a value for this option to control how many columns text will be indented when using indent operations (such as << or >>) in normal or visual mode; this also covers automatic C-style indentation.

softtabstop

This option results in different behaviours depending on its own value and the one set for tabstop and the status of the expandtab toggle:

• softtabstop < tabstop, noexpandtab - This will result in a combination of tabs and spaces to make up the total spacing
• softtabstop == tabstop, noexpandtab - This will always force the use of tabs
• expandtab - The value of softtabstop will be ignored and spaces will be forced

Examples

So here’s an example of how to use all of the above in your vimrc file or in ftplugin resources:

" Example of typical indentation for Python code, i.e. 4 spaces
set expandtab
set tabstop=4
set shiftwidth=4

You can also set those values on depending on the file type directly in vimrc:

autocmd FileType ruby setlocal expandtab tabstop=2 shiftwidth=2 softtabstop=2

If you’re insane enough to feel like learning even more about indentation in Vim, I’d suggest going through the reference material put together by Ted Logan.

Happy indenting!