TITLE: Task management macros in Vim
DATE: 2019-05-25
AUTHOR: John L. Godlee
====================================================================


I'm slowly trying to emulate parts of the Emacs Org-mode syntax. 
Particularly, when I write TODO lists, having [ ] or [*] at the 
beginning of a line to indicate whether that task is 'pending' or 
'done', respectively. I'm not ready to dive straight into a Vim 
Org-mode plugin, but I have started to write little functions to 
make editing the files slightly more efficient. One such keybinding 
is simply to toggle whether a task is marked as 'done' or 'pending':

  [Emacs Org-mode syntax]: https://orgmode.org/guide/

    " Toggle task as done
    autocmd Filetype text,markdown nnoremap <Leader>D :call 
ToggleTask()<CR>

    function! ToggleTask()
        if (getline('.') =~ '^\[\*\]')>0      " If you find [*] at 
line start
            .s/^\[\*\]/[ ]/g
        elseif (getline('.') =~ '^\[\ \]')>0  " OR If you find [ ] 
at line start
            .s/^\[\ \]/[*]/g
        else                                  " OR if neither
            echom 'Not a task line'
        endif
    endfunction

The keybinding applies to text and markdown files and is called by 
<Leader>d. This calls a function named ToggleTask(). The function 
searches the current cursor line to see if it contains [*] and if 
it does, replaces it with [ ], then if [*] isn't found it does the 
opposite, searching for [ ] and changing it to [*], finally if 
neither of the abov regexes are matched, a message echom is 
displayed stating that the cursor line is not a task.

Similarly, I have the line below which makes a line a task line 
simply by prepending it with [ ]:

    autocmd Filetype text,markdown nnoremap <Leader>T :s/^/[ ] /g 
<CR>

These aren't perfect by any stretch, it would be nicer to roll the 
whole lot into a more intelligent single function that can toggle 
between 'not a task', 'task to do', 'finished task', that would 
also take into account common line prefixes like enumerated lists.

Update - 2019_06_06

I did what I said I would do and rolled it all into one function:

    " Create and toggle done status of task lines
    autocmd Filetype text,markdown nnoremap <Leader>z :call 
ToggleTask()<CR>

    function! ToggleTask()
        if (getline('.') =~ '^\[x\]')>0       " IF you find [x] at 
line start
            .s/^\[x\]/[ ]/g
        elseif (getline('.') =~ '^\[\ \]')>0  " OR if you find [ ] 
at line start
            .s/^\[\ \]/[x]/g
        elseif (getline('.') =~ '^\d\+\.\ \[\ \]')>0  " OR if the 
line begins with 1. [ ]
            .s/\[\ \]/[x]/g
        elseif (getline('.') =~ '^\d\+\.\ \[x\]')>0  " OR if the 
line begins with 1. [x]
            .s/\[x\]/[ ]/g
        elseif (getline('.') =~ '^\d\+\.')>0  " OR if the line 
begins with a 1.
            .s/\d\+\./& [ ]/
        elseif (getline('.') =~ '^\*\|-')>0   " OR if the line 
begins with a * or -
            .s/^\*\|-/[ ]/
        else                                  " OR if none
            .s/^/[ ] /g
        endif
    endfunction