Is there a text object or motion for non-comment lines are not separated from comment lines by blank lines? E.g., in git commit messages

Question

Consider the text

A
B
# C
# D

Is there a text object or motion that will select lines A and B if the cursor is on either, but not select lines C and D? ap or ip with the cursor on any of those four lines will select all four, since there is not a blank line between C and D.

Use case: git commit messages. For example:

Added glob tests; bugfix in fnmatch

Run `CTEST_OUTPUT_ON_FAILURE=1 ctest .` to see the inputs for glob tests
that fail.
# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.

If I put the cursor on the Run... line and wrap it with gqap, all of the #... comment lines get wrapped in:

Run `CTEST_OUTPUT_ON_FAILURE=1 ctest .` to see the inputs for glob tests
that fail.  # Please enter the commit message for your changes. Lines
starting # with '#' will be ignored, and an empty message aborts the

I would like gq<something> to select only the non-# lines and wrap them. The only workaround I can think of so far is v/^#<CR>jgq, which seems rather tedious.

Another use case:

Being able to distinguish comment lines from non-comment lines would also help me select Doxygen comments before functions:

/// Comment here                      A
/// More comment here                 B
void do_something_interesting() {     C
}                                     D

Same deal: I'd like to be able to select A+B without C+D or vice versa.

Answer 1

Define syntax match gitcommitBody for the custom text object syntax

Install vim-textobj-user and vim-textobj-syntax. The default syntax file for gitcommit does not define gitcommitBody. Place following line

syn match   gitcommitBody   "\%>2l[^#].*" contains=@Spell

into the file ~/.vim/after/ftplugin/gitcommit.vim.

This defines for all lines except the first two and comment lines of a gitcommit buffer the syntax match gitcommitBody.

You could also add it to your vimrc with

augroup Mysyntax
  autocmd!
  autocmd FileType gitcommit syn match   gitcommitBody  "\%>2l[^#].*" contains=@Spell
augroup END

However, if you have many autocommands, filetype is tested for each autocommand, which is not efficient. Furthermore, you replicate something that Vim already does automatically anyway (see also the reddit post where_to_put_filetype_specific_stuff by romainl).

For a typical gitcommit buffer, the syntax groups are now :

Without the additional syntax definition the body would belong to no syntax group at all and could not be adressed by the custom text object vim-textobj-syntax.

Now you can press

gqiy

to reflow the gitcommitBody to