elisp: Kill Ring Concepts

 
 31.8.1 Kill Ring Concepts
 -------------------------
 
 The kill ring records killed text as strings in a list, most recent
 first.  A short kill ring, for example, might look like this:
 
      ("some text" "a different piece of text" "even older text")
 
 When the list reaches ‘kill-ring-max’ entries in length, adding a new
 entry automatically deletes the last entry.
 
    When kill commands are interwoven with other commands, each kill
 command makes a new entry in the kill ring.  Multiple kill commands in
 succession build up a single kill ring entry, which would be yanked as a
 unit; the second and subsequent consecutive kill commands add text to
 the entry made by the first one.
 
    For yanking, one entry in the kill ring is designated the front of
 the ring.  Some yank commands rotate the ring by designating a different
 element as the front.  But this virtual rotation doesn’t change the list
 itself—the most recent entry always comes first in the list.