path: root/autoload/regex_escape.vim
blob: 239080474bd10e3054a0a5e3d46d62c2e2f52a97 (plain) (tree)


" Define Vim pattern character classes of characters that should have an
" escape character added before them to make them literal, for use in
" substitute()
let s:classes = {
      \ 'bre': '[][\.*?^$]',
      \ 'ere': '[][\.*?^$+{}()/]',
      \ 'vim': '[][\.*^$~]'
      \ }

" This function does the actual translation, defined as 'operatorfunc' for the
" mapping in both normal and visual mode
function! regex_escape#Operatorfunc(type) abort

  " Save the current value of the unnamed register and the current value of
  " the 'clipboard' and 'selection' options into a dictionary for restoring
  " after this is all done
  let l:save = {
        \ 'register': @@,
        \ 'clipboard': &clipboard,
        \ 'selection': &selection
        \ }

  " Don't involve any system clipboard for the duration of this function
  set clipboard-=unnamed
  set clipboard-=unnamedplus

  " Ensure that we include end-of-line and final characters in selections
  set selection=inclusive

  " Select or re-select text, depending on how we were invoked
  if a:type ==# 'line'
    normal! '[V']y
  elseif a:type ==# 'block'  " Typically doesn't work too well
    execute "normal! `[\<C-V>`]y"
    normal! `[v`]y

  " Determine the regex flavor to use; if one is defined for the buffer, use
  " that; failing that, if one is defined globally in g:regex_escape_flavor,
  " use that; failing that, just use 'bre'
  let l:flavor = get(b:, 'regex_escape_flavor',
        \ get(g:, 'regex_escape_flavor', 'bre'))

  " Get the corresponding character class
  let l:class = s:classes[l:flavor]

  " Perform the substitution on the unnamed register's contents, inserting a
  " backslash before every instance of any character in that class
  let @@ = substitute(@@, l:class, '\\&', 'g')

  " Paste our substituted changes back in over the top of the previously
  " selected text, by reselecting it before the paste
  normal! gvp

  " Restore contents of the unnamed register and the previous values of the
  " 'clipboard' and 'selection' options.
  let @@ = l:save['register']
  let &clipboard = l:save['clipboard']
  let &selection = l:save['selection']


" Expression mapping target function; set the 'operatorfunc' and return the
" key sequence to active it
function! regex_escape#Map() abort
  set operatorfunc=regex_escape#Operatorfunc
  return 'g@'