How to ignore a column when visually selecting a paragraph

Question

I have a file that looks like this:

# Section 1
#
# new: a.txt
# new: b.txt
#
#
# Section 2
#
# [n]ew: c.txt
# new: d.txt
# new: e.txt
#

My cursor is on the first new of the second section and I want to select all the "paragraph", i.e. the 3 new lines starting at this one. But because the paragraph is defined as a set of non-empty lines, vip selects all the file.

How can I select only those 3 lines? This should apply for any number of lines and the cursor should be placed anywhere in the "paragraph", i.e. vip/equivalent should select the current new paragraph.

My question is the following:

How can I omit a column of text when visually selecting a paragraph?

Answer 1

Using Kana Natsuno's textobj-user: install textobj-user, then put the following in a file textobj-comment-lines/plugin/textobj/comment_lines.vim:

if exists('g:loaded_textobj_comment_lines')
    finish
endif
let g:loaded_textobj_comment_lines = 1

let s:save_cpo = &cpo
set cpo&vim

call textobj#user#plugin('commentlines', {
    \   '-': {
    \     'select-a': "a#",  '*select-a-function*': 'CommentLinesSelectA',
    \     'select-i': "i#",  '*select-i-function*': 'CommentLinesSelectI'
    \   }
    \ })

function! CommentLinesSelectA() " {{{1
    if getline(line('.')) !~# '\m^#.*\S'
        return 0
    endif

    let head_pos = search('\m\%(\%^\|^\n\|^[^#].*\n\|^#\s*\n\)\zs#.*\S', 'cbnW')
    let tail_pos = search('\m\%#.*\n\%(^#.*\S.*\n\)*\%(^#\s*\n\)*\zs\%(^#\s*\n\)', 'cnW')
    if tail_pos > 0
        if getline(tail_pos) !~# '\m^#'
            let tail_pos -= 1
        endif
    else
        let tail_pos = search('\m^#.*\S.*\n\ze\%(\%$\|^\n\|^[^#].*\n\|^#\s*\n\)', 'cnW')
    endif
    return ['V', [0, head_pos, 1, 0], [0, tail_pos, 1, 0]]
endfunction " }}}1

function! CommentLinesSelectI() " {{{1
    if getline(line('.')) !~# '\m^#.*\S'
        return 0
    endif

    let head_pos = search('\m\%(\%^\|^\n\|^[^#].*\n\|^#\s*\n\)\zs#.*\S', 'cbnW')
    let tail_pos = search('\m^#.*\S.*\n\ze\%(\%$\|^\n\|^[^#].*\n\|^#\s*\n\)', 'cnW')
    if !tail_pos
        let tail_pos = line('$')
    endif
    return ['V', [0, head_pos, 1, 0], [0, tail_pos, 1, 0]]
endfunction " }}}1

let &cpo = s:save_cpo
unlet s:save_cpo

" vim: set sw=4 sts=4 fdm=marker:

This adds two mappings, vi# and va#, and the first one does what you want. The gist is the regexp searches, the rest is mostly boilerplate.

The comments are hard-coded to # anchored at the beginning of line. Dealing with other kinds of comments (f.i. /* ... */) would be possible, but not trivial. You can, of course, refine this in many ways.

Reference: textobj-user user manual.

Answer 2

You could delete the first column, then select the paragraph with vip, then restore the deleted #'s and reselect the last visual selection with gv. Basically something like this mapped to the Q key for example:

nnoremap Q :%s/^#// \| exe 'norm!``vip"9y' \| silent %s/^/#/ \| nohl \| norm!gv<CR>

It yanks the paragraph into register 9 just so vim will remember the selection for the gv command.

Answer 3

An alternative is ?#$<cr>jVNk:

?#$ jumps back to the previous occurrence of # on its own line ($ in regex means "end of line"), j moves to the start of the paragraph to select, we start Visual mode and move to the Next occurrence of # by itself, and finally move back up one line with k.

This is relatively short, so you can type it manually when necessary to avoid having to bind a key to it, but it does have the disadvantage that it clobbers the search history. If you do make it a mapping, though, you can keep search history intact with

:execute "keeppatterns normal! ?#$\<cr>jV/#$\<cr>k"

or the shorthand

:exe "keepp norm! ?#$\<cr>jV/#$\<cr>k"

Answer 4

If you do not mind leaving dirty marks behind you can use them to mark the paragraph. i.e. you can:

• mark your position,
• select the entire commented text,
• return to the mark
• vip to select the paragraph
• use marks again to mark the paragraph itself
• undo the change
• use the marks to select the single paragraph

Here is the code:

nnoremap <leader>vip mqvip:s/^./<cr>`qvip<esc>`<mw`>meu`w0v`e$

Explanation:

• mq marks the current position
• vip selects the problematic paragraph
• s/^./<cr> removes the problematic characters (can be adapted to other forms of comments)
• `q returns the cursor to the original position
• vip now selects the desired paragraph
• <esc> forces the current visual to be the latest selection
• `<mw marks the beginning of the desired paragraph
• `>me marks the end of the desired paragraph
• u undoes the change, puts the comments back
• `w0 goes to the beginning of the desired paragraph
• v enters visual mode
• `e$ moves to the end of the desired paragraph completing the selection.

This is a little dirty since the marks end one character off after the undo, that is the reason to use 0 and $ in the final selection.

Answer 5

Unfortunately, vim doesn't yet support custom-defined paragraphs (from :h todo).

• Add regex for 'paragraphs' and 'sections': 'parare' and 'sectre'. Combine the two into a regex for searching. (Ned Konz)

Not all hope is lost though, regex to the rescue!!!

EDIT: A function to do it!

function! SelectBlock()
  execute "normal! ?#\\s*$\<cr>" "go to top of current block
  execute "normal! j" " go down one line
  execute "normal! v/\\_.#\\s*$\<cr>" "visually select to end of block
endfunction

You can type :call SelectBlock() or map it to something to make this happen. It works wherever your cursor is. To do it, type v/\_.#\s*$, which will match all the lines under the current line (including the current line) until a line with a # followed by non-whitespace characters.

Explanation of the last command:

v - visual select mode

/ - select until the following search result (our regex)

\_. - select any characters, including newlines

#\s*$ - end the regex match if there's a line with a # followed by nothing but whitespace