anchor.diff:  == Builtin options
   
   *tabstop* `int`::
  -    *default* 8 +
  +    _default_ 8 +
       width of a tab character
   
   *indentwidth* `int`::
  -    *default* 4 +
  +    _default_ 4 +
       width (in spaces) used for indentation, 0 means a tab character
   
   *scrolloff* `coord`::
  -    *default* 0,0 +
  +    _default_ 0,0 +
       number of lines, columns to keep visible around the cursor when
       scrolling
   
   *eolformat* `enum(lf|crlf)`::
  -    *default* lf +
  +    _default_ lf +
       the format of end of lines when writing a buffer, this is autodetected
       on load; values of this option assigned to the `window` scope are
       ignored
   
   *BOM* `enum(none|utf8)`::
  -    *default* none +
  +    _default_ none +
       define if the file should be written with a unicode byte order mark;
       values of this option assigned to the `window` scope are ignored
   
   *readonly* `bool`::
  -    *default* false +
  +    _default_ false +
       prevent modifications from being saved to disk, all buffers if set
       to `true` in the `global` scope, or current buffer if set in the
       `buffer` scope; values of this option assigned to the `window`
       scope are ignored
   
   *incsearch* `bool`::
  -    *default* true +
  +    _default_ true +
       execute search as it is typed
   
   *aligntab* `bool`::
  -    *default* false +
  +    _default_ false +
       use tabs for alignment command
   
   *autoinfo* `flags(command|onkey|normal)`::
  -    *default* command|onkey +
  +    _default_ command|onkey +
       display automatic information box in the enabled contexts
   
   *autoshowcompl* `bool`::
  -    *default* true +
  +    _default_ true +
       automatically display possible completions when editing a prompt
   
   *ignored_files* `regex`::
  
positive.code:     actions should hook on this option changing for activation/deactivation
  
  *path* `str-list`::
      *default* ./:/usr/include +
      directories to search for gf command
  
  *completers* `completer-list`::
      *default* filename:word=all +
      completion engines to use for insert mode completion (they are tried
      in order until one generates candidates). Existing completers are:
  
  
negative.code:     as word character for the purpose of insert mode completion.
  
  *autoreload* `enum(yes|no|ask)`::
      _default_ ask +
      auto reload the buffers when an external modification is detected
  
  *debug* `flags(hooks|shell|profile|keys|commands)`::
      dump various debug information in the '\*debug*' buffer
  
  *idle_timeout* `int`::
      _default_ 50 +
      timeout, in milliseconds, with no user input that will trigger the
      *PromptIdle*, *InsertIdle* and *NormalIdle* hooks, and autocompletion.
  
  *fs_checkout_timeout* `int`::
      _default_ 500 +
      timeout, in milliseconds, between checks in normal mode of modifications
      of the file associated with the current buffer on the filesystem.
  
  