"
" toggle_option_flags.vim: Provide commands to toggle flags in grouped options
" like 'formatoptions', 'shortmess', 'complete', 'switchbuf', etc.
"
" Author: Tom Ryder <tom@sanctum.geek.nz>
" License: Same as Vim itself
"
if exists('g:loaded_toggle_option_flags') || &compatible
finish
endif
if !has('user_commands') || v:version < 600
finish
endif
let g:loaded_toggle_option_flags = 1
" Show an error-highlighted message and beep, but without a real :echoerr
function! s:Error(message)
execute 'normal! \<Esc>'
echohl ErrorMsg
echomsg a:message
echohl None
endfunction
" Test whether an option currently has a flag as part of its value
function! s:Has(option, flag)
" Horrible :execute to get the option's current setting into a variable
" (I couldn't get {curly braces} indirection to work)
let l:current = ''
execute 'let l:current = &' . a:option
" If the flag we're toggling is longer than one character, this must by
" necessity be a delimited option. I think all of those in VimL are
" comma-separated. Extend the flag and value so that they'll still match at
" the start and end. Otherwise, use them as-is.
if strlen(a:flag) > 1
let l:search_flag = ',' . a:flag . ','
let l:search_value = ',' . l:current . ','
else
let l:search_flag = a:flag
let l:search_value = l:current
endif
" Return whether
return stridx(l:search_value, l:search_flag) > -1
endfunction
" Internal function to do the toggling
function! s:Toggle(option, flag, local)
" Check for spurious option strings, we don't want to :execute anything funny
if a:option =~# '\m\L'
call s:Error('Illegal option name')
return 0
endif
" Check the option actually exists
if !exists('&' . a:option)
call s:Error('No such option: ' . a:option)
return 0
endif
" Choose which set command to use
let l:set = a:local
\ ? 'setlocal'
\ : 'set'
" Find whether the flag is set before the change
let l:before = s:Has(a:option, a:flag)
" Assign -= or += as the operation to run based on whether the flag already
" appears in the option value or not
let l:operation = l:before
\ ? '-='
\ : '+='
" Try to set the option; suppress errors, we'll check our work
silent! execute l:set
\ . ' '
\ . a:option . l:operation . escape(a:flag, '\ ')
" Find whether the flag is set after the change
let l:after = s:Has(a:option, a:flag)
" If we made a difference, report the new value; if we didn't, admit it
if l:before != l:after
execute l:set . ' ' . a:option . '?'
else
call s:Error('Unable to toggle '.a:option.' flag '.a:flag)
endif
" Return value is whether we made a change
return l:before != l:after
endfunction
" User commands wrapping around calls to the above function
command -nargs=+ -complete=option
\ ToggleOptionFlag
\ call <SID>Toggle(<f-args>, 0)
command -nargs=+ -complete=option
\ ToggleOptionFlagLocal
\ call <SID>Toggle(<f-args>, 1)
