Twiddle options to make the line number feature more accessible

CycleLineNumberDisplay.vim

" Cycle Line Number Display: serialized by Max Cantor
" Twiddle options to make the line number feature more accessible
"
" Notes:
" for a list of useful arguments to :hilight
" :help highlight-args
"
" example highlight customization
" :highlight LineNr cterm=NONE ctermbg=black ctermfg=cyan

nnoremap <silent> <Space> :call CycleLineNumberDisplay()<CR>

function! CycleLineNumberDisplay()
  " DNR
  if &number && &relativenumber
    set norelativenumber
  elseif &number && !&relativenumber
    set nonumber
  elseif !&number && !&relativenumber
    set number relativenumber
  endif
endfunction