Vim Comment Box Macro

Question

I write comments of the form

#############
## Example ##
#############

Always one line, always just like that. It's a way of breaking up code more visually. I have lately taken to the following way of typing them out:

1. Type double #, space, the comment, space, double #.
2. Look at the ruler in right hand corner for the horizontal position.
3. <esc>ki#<esc><the_number_from_step_2_minus_one>.<esc>yyjp to enter n #'s, yank it, and paste it at the bottom.

But even this seems redundant. I would like to define a macro of the form:

:let @a='k<n>#i<esc><esc>yyjp<esc>'

Where <n> is the length of the line I will execute the macro on:

## Example ##

But I do not know how to record and store the position of the last character on the particular line. Suggestions?

I have found this suggestion from the vim wikia but I don't want a plugin, and this from Stack Overflow but this seems like overkill again.

Note: I don't use any plugins and would prefer not to. I literally have none. And a fairly short vimrc (<50 lines after a recent doubling).

Answer 1

You don’t need to know the length of the line. This ought to do it:

:let @a = 'yyPVr#jpVr#'

I’d also automate the adding of the hashes at the start and end of the middle line:

:let @a = "I## \<Esc>A ##\<Esc>yyPVr#jpVr#"