Info Catalog elisp: Commands for Insertion elisp: Text elisp: User-Level Deletion

elisp: Deletion

 
 31.6 Deleting Text
 ==================
 
 Deletion means removing part of the text in a buffer, without saving it
 in the kill ring (The Kill Ring).  Deleted text can’t be yanked,
 but can be reinserted using the undo mechanism (Undo).  Some
 deletion functions do save text in the kill ring in some special cases.
 
    All of the deletion functions operate on the current buffer.
 
  -- Command: erase-buffer
      This function deletes the entire text of the current buffer (_not_
      just the accessible portion), leaving it empty.  If the buffer is
      read-only, it signals a ‘buffer-read-only’ error; if some of the
      text in it is read-only, it signals a ‘text-read-only’ error.
      Otherwise, it deletes the text without asking for any confirmation.
      It returns ‘nil’.
 
      Normally, deleting a large amount of text from a buffer inhibits
      further auto-saving of that buffer because it has shrunk.  However,
      ‘erase-buffer’ does not do this, the idea being that the future
      text is not really related to the former text, and its size should
      not be compared with that of the former text.
 
  -- Command: delete-region start end
      This command deletes the text between positions START and END in
      the current buffer, and returns ‘nil’.  If point was inside the
      deleted region, its value afterward is START.  Otherwise, point
      relocates with the surrounding text, as markers do.
 
  -- Function: delete-and-extract-region start end
      This function deletes the text between positions START and END in
      the current buffer, and returns a string containing the text just
      deleted.
 
      If point was inside the deleted region, its value afterward is
      START.  Otherwise, point relocates with the surrounding text, as
      markers do.
 
  -- Command: delete-char count &optional killp
      This command deletes COUNT characters directly after point, or
      before point if COUNT is negative.  If KILLP is non-‘nil’, then it
      saves the deleted characters in the kill ring.
 
      In an interactive call, COUNT is the numeric prefix argument, and
      KILLP is the unprocessed prefix argument.  Therefore, if a prefix
      argument is supplied, the text is saved in the kill ring.  If no
      prefix argument is supplied, then one character is deleted, but not
      saved in the kill ring.
 
      The value returned is always ‘nil’.
 
  -- Command: delete-backward-char count &optional killp
      This command deletes COUNT characters directly before point, or
      after point if COUNT is negative.  If KILLP is non-‘nil’, then it
      saves the deleted characters in the kill ring.
 
      In an interactive call, COUNT is the numeric prefix argument, and
      KILLP is the unprocessed prefix argument.  Therefore, if a prefix
      argument is supplied, the text is saved in the kill ring.  If no
      prefix argument is supplied, then one character is deleted, but not
      saved in the kill ring.
 
      The value returned is always ‘nil’.
 
  -- Command: backward-delete-char-untabify count &optional killp
      This command deletes COUNT characters backward, changing tabs into
      spaces.  When the next character to be deleted is a tab, it is
      first replaced with the proper number of spaces to preserve
      alignment and then one of those spaces is deleted instead of the
      tab.  If KILLP is non-‘nil’, then the command saves the deleted
      characters in the kill ring.
 
      Conversion of tabs to spaces happens only if COUNT is positive.  If
      it is negative, exactly −COUNT characters after point are deleted.
 
      In an interactive call, COUNT is the numeric prefix argument, and
      KILLP is the unprocessed prefix argument.  Therefore, if a prefix
      argument is supplied, the text is saved in the kill ring.  If no
      prefix argument is supplied, then one character is deleted, but not
      saved in the kill ring.
 
      The value returned is always ‘nil’.
 
  -- User Option: backward-delete-char-untabify-method
      This option specifies how ‘backward-delete-char-untabify’ should
      deal with whitespace.  Possible values include ‘untabify’, the
      default, meaning convert a tab to many spaces and delete one;
      ‘hungry’, meaning delete all tabs and spaces before point with one
      command; ‘all’ meaning delete all tabs, spaces and newlines before
      point, and ‘nil’, meaning do nothing special for whitespace
      characters.
 

Info Catalog elisp: Commands for Insertion elisp: Text elisp: User-Level Deletion