Re: M-\ does not work with prefix argument as documented

[Kevin Rodgers]

Dieter Wilhelm wrote:
> Hi 
>
> emacs -Q -D
>
> Insert a line like the following:
>
> otto      foo
>        ^
>
> Place the cursor approximately where the accent is.  Type M-- M-\ and
> all white space is deleted instead of only the one on the left hand
> side.

Neither the Emacs manual nor the delete-horizontal-space's doc string
says anything about how prefix args are handled.  But it seems like a
good idea to bind the BACKWARD-ONLY Lisp arg to the interactive prefix
arg:

2006-12-13  Kevin Rodgers  <address@hidden>

        * simple.el (delete-horizontal-space): Bind optional BACKWARD-ONLY
        arg to interactive prefix arg, and update doc string.

        * killing.texi (Deletion): Describe `M-\'
        (delete-horizontal-space) prefix argument.


*** simple.el.orig      2006-12-04 05:51:48 -0000
--- simple.el   2006-12-13 09:40:19.509429600 -0700
***************
*** 706,713 ****

  (defun delete-horizontal-space (&optional backward-only)
    "Delete all spaces and tabs around point.
! If BACKWARD-ONLY is non-nil, only delete spaces before point."
!   (interactive "*")
    (let ((orig-pos (point)))
      (delete-region
       (if backward-only
--- 706,713 ----

  (defun delete-horizontal-space (&optional backward-only)
    "Delete all spaces and tabs around point.
! With prefix arg BACKWARD-ONLY, only delete spaces and tabs before point."
!   (interactive "*P")
    (let ((orig-pos (point)))
      (delete-region
       (if backward-only


*** killing.texi.orig   2006-07-24 17:46:22 -0000
--- killing.texi        2006-12-13 09:39:38 -0700
***************
*** 148,154 ****
    The other delete commands are those which delete only whitespace
  characters: spaces, tabs and newlines.  @kbd{M-\}
  (@code{delete-horizontal-space}) deletes all the spaces and tab
! characters before and after point.  @address@hidden
  (@code{just-one-space}) does likewise but leaves a single space after
  point, regardless of the number of spaces that existed previously (even
  if there were none before).  With a numeric argument @var{n}, it
--- 148,155 ----
    The other delete commands are those which delete only whitespace
  characters: spaces, tabs and newlines.  @kbd{M-\}
  (@code{delete-horizontal-space}) deletes all the spaces and tab
! characters before and after point.  With a prefix argument, it only
! delete spaces and tabs before point.  @address@hidden
  (@code{just-one-space}) does likewise but leaves a single space after
  point, regardless of the number of spaces that existed previously (even
  if there were none before).  With a numeric argument @var{n}, it


> Could you, please, also make the command symmetric? For example
> negative arguments are killing on the left hand side of the point and
> positive arguments on the left hand side.  The default would remain as
> is.  (There was recently a request--unrelated to M-\--for such a
> feature on gnu.emacs.help, killing white space left or right of the
> cursor).

That would be cool.

--
Kevin