anchor.diff:  For nestable objects, a count can be used in order to specify which surrounding
   level to select. Object selections are repeatable using *<a-.>*.
   
  +=== Whole object
  +
  +A 'whole object' is an object *including* its surrounding characters.
  +For example, for a quoted string this will select the quotes, and
  +for a word this will select trailing spaces.
  +
   *<a-a>*::
       select the whole object
   
  +*[*::
  +    select to the whole object start
  +
  +*]*::
  +    select to the whole object end
  +
  +*{*::
  +    extend selections to the whole object start
  +
  +*}*::
  +    extend selections to the whole object end
  +
  +=== Inner object
  +
  +An 'inner object' is an object *excluding* its surrounding characters.
  +For example, for a quoted string this will *not* select the quotes, and
  +for a word this will *not* select trailing spaces.
  +
   *<a-i>*::
  -    select the inner object, that is the object excluding its surrounder.
  -    For example, for a quoted string, this will not select the quote, and
  -    for a word this will not select trailing spaces.
  -
  -*[*::
  -    select to object start
  -
  -*]*::
  -    select to object end
  -
  -*{*::
  -    extend selections to object start
  -
  -*}*::
  -    extend selections to object end
  -
  -After these keys, a second key needs to be entered in order to specify
  -the wanted object:
  +    select the inner object
  +
  +*<a-[>*::
  +    select to the inner object start
  +
  +*<a-]>*::
  +    select to the inner object end
  +
  +*<a-{>*::
  +    extend selections to the inner object start
  +
  +*<a-}>*::
  +    extend selections to the inner object end
  +
  +=== Objects types
  +
  +After the keys described above, a second key needs to be entered
  +in order to specify the wanted object:
   
   *b*, *(*, *)*::
       select the enclosing parenthesis
  
positive.code: 
  *<a-:>*::
      ensure selections are in forward direction (cursor after anchor)
  
  *<a-.>*::
      repeat last object or *f*/*t* selection command
  
  == Changes
  
  
negative.code: *<a-[ft]>*::
      same as [ft] but in the other direction
  
  *<a-.>*::
      repeat last object or *f*/*t* selection command
  
  *m*::
      select to matching character, see the `matching_pairs` option
      in <<options#,`:doc options`>>
  