How do I shift the line indent to a specific value?

Question

Many times I run across a situation where a line is not indented properly. Ether through a paste, bad / not preferred indent plugin, or most often extra spaces offsetting the indent value. I usually fix this by << or >> the line a few times to fix it up. In the case of extra spaces I'll do a 100<< then a >> for each indent level I actually want.

The question is, like the | motion that lets you set the column by number 10| sends the cursor to the 10th column. How can I specify the indent level?

An example (this does not work) with shiftwidth=4 expandtab:

The quick (indent level 0)
••••Brown Fox (indent level 1)
••••••••••Jumped over the lazy dog (indent level 2 with two extra spaces)

In this case I currently have to count the indent level of the last line (2) and add one for the extra spaces then type 3<< then count the indent level of what I then 1>> (or use autoindent and == command).

I'm asking for something like 1== to force the indent to be indent level 1. Or in some cases 0== for removing an indent all together.

I realize the above example does auto indenting on 1 or 0 lines (respectively) and so does not do what I'd like but hoped it would help illustrate the question better.

Answer 1

You can use the :left command:

:[range]le[ft] [indent]
Left-align lines in [range]. Sets the indent in the lines to [indent] (default 0). {not in Vi}

Note that :left sets the indent to n spaces, and is not aware of shiftwidth or tabstop, so using :left 8 will use 8 spaces.

If you want to set the indentation level, you can easily define a command:

command! -nargs=1 Left execute 'left ' . &sw * <args>

Use :Left 2 will set the indentation to 8 spaces.

To map this to <Leader>=, you could use:

noremap <expr> <Leader>= ':left ' . str2nr(nr2char(getchar())) * &sw . '<CR>'

I'm not sure if this is the best way, but it's the only way I can manage... \=2 will indent the current line to 8 spaces, and 5\=3 will indent the next 5 lines to 12 spaces.

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A related hint that also solves your problem is setting the shiftround option. From :help 'shiftround'

Round indent to multiple of 'shiftwidth'. Applies to > and < commands. CTRL-T and CTRL-D in Insert mode always round the indent to a multiple of 'shiftwidth' (this is Vi compatible).

In your example, the first << will "round" to 8 spaces. So your problem (using 3<< and then >>) is solved. And as the help page says, you can also use <C-d> from insert mode.