How to programmatically visually select a text block?

Question

Is there a way to select a text block (e.g. a first word "TODO:") programmatically (with some commands or functions from a script)? Not simply highlight, like with a search, but visually select like with mouse?

Answer 1

If you are looking to visually select a search pattern you can do it using two commands. For example searching for "TODO...." lines:

/^TODO.*$/s
v//e

This will search your your pattern and then visually select to the end of it.

If you want to move this to a function and then be able to call it in a single action:

function! VisualSelectSearch (query)
  execute "normal /".a:query."/s\<CR>v//e\<CR>"
endfunction

command! -nargs=+ VSS call VisualSelectSearch(<q-args>)

Now you can type :VSS ^TODO.*$ and visually select the next instance. If you want to call the function directly in a script use VisualSelectSearch("^TODO.*$").

Answer 2

Any sequence of key presses can be represented in vimscript with the :normal command. For instance, to visually select the next occurrence of "TODO:" you might normally hit the following keys:

/TODO:<CR>        jump to the next occurence of TODO:
v                 start a visual selection (on the T)
f:                jump to the next ':'

To simulate these key presses in vimscript, you'd want to write something like:

normal! /TODO:<CR>vf:

However, typing <CR> will literally type < C R > instead of enter. To get around this, we have to wrap this in an execute command:

execute "normal! /TODO:\<CR>vf:"

I recommend reading :help normal and Learn Vimscript the Hard Way for more information.