Remove sexp without deleting contents

Remove sexp without deleting contents

[Tim Johnson]

This poses a rather trivial question, but I'm betting on some
seredipity from responses.

Suppose I want to remove an extraneous sexp. The following code
is simplistic:
(defun tj-toggle-menu-visible ()
  "Toggle visibility of menu bar and switches to tmm-style menus"
  (interactive)
  (if tj-menu-visible
      (progn
	    (setq tj-menu-visible nil)
	    (menu-bar-mode -1)
	    (setq tj-is-windows nil))
    (progn
      (setq tj-menu-visible t)
      (menu-bar-mode 1)
      (setq tj-is-windows window-system))))

;; Suppose I want to remove the second `progn form, but not the
enclosed sequences. In this simple block of code of code it's pretty
hard to screw up: just delete/kill the line with "(progn" and any
right parens from the last line. In a more complex example I might
delete a parens whose absence could introduce unexpected and
problematic side effects.

Is there function that might (effectively) simultaneously remove the
beginning of sexp and the matching closing paren, leaving inner
contents intact?

thanks.

-- 
Tim Johnson
http://www.tj49.com

Re: Remove sexp without deleting contents

[Eric Abrahamsen]

Tim Johnson <tim@akwebsoft.com> writes:

> This poses a rather trivial question, but I'm betting on some
> seredipity from responses.
>
> Suppose I want to remove an extraneous sexp. The following code
> is simplistic:
> (defun tj-toggle-menu-visible ()
>   "Toggle visibility of menu bar and switches to tmm-style menus"
>   (interactive)
>   (if tj-menu-visible
>       (progn
> 	    (setq tj-menu-visible nil)
> 	    (menu-bar-mode -1)
> 	    (setq tj-is-windows nil))
>     (progn
>       (setq tj-menu-visible t)
>       (menu-bar-mode 1)
>       (setq tj-is-windows window-system))))
>
> ;; Suppose I want to remove the second `progn form, but not the
> enclosed sequences. In this simple block of code of code it's pretty
> hard to screw up: just delete/kill the line with "(progn" and any
> right parens from the last line. In a more complex example I might
> delete a parens whose absence could introduce unexpected and
> problematic side effects.
>
> Is there function that might (effectively) simultaneously remove the
> beginning of sexp and the matching closing paren, leaving inner
> contents intact?

I would guess a majority of people who do a lot of lisp/elisp editing
use the paredit package (in the repos). Maybe not a majority, who knows,
but it's really useful. It lets you edit lisp code "logically": by atoms
and sexps, rather than character-by-character. In paredit, the command
`paredit-splice-sexp-killing-backward' would do what you want, it's
bound to M-<up>.

HTH,
Eric

Re: Remove sexp without deleting contents

[Tim Johnson]

* Eric Abrahamsen <eric@ericabrahamsen.net> [180929 18:07]:
> Tim Johnson <tim@akwebsoft.com> writes:
> 
> > This poses a rather trivial question, but I'm betting on some
> > seredipity from responses.
> >
> > Suppose I want to remove an extraneous sexp. The following code
> > is simplistic:
> > (defun tj-toggle-menu-visible ()
> >   "Toggle visibility of menu bar and switches to tmm-style menus"
> >   (interactive)
> >   (if tj-menu-visible
> >       (progn
> > 	    (setq tj-menu-visible nil)
> > 	    (menu-bar-mode -1)
> > 	    (setq tj-is-windows nil))
> >     (progn
> >       (setq tj-menu-visible t)
> >       (menu-bar-mode 1)
> >       (setq tj-is-windows window-system))))
> >
> > ;; Suppose I want to remove the second `progn form, but not the
> > enclosed sequences. In this simple block of code of code it's pretty
> > hard to screw up: just delete/kill the line with "(progn" and any
> > right parens from the last line. In a more complex example I might
> > delete a parens whose absence could introduce unexpected and
> > problematic side effects.
> >
> > Is there function that might (effectively) simultaneously remove the
> > beginning of sexp and the matching closing paren, leaving inner
> > contents intact?
> 
> I would guess a majority of people who do a lot of lisp/elisp editing
> use the paredit package (in the repos). Maybe not a majority, who knows,
> but it's really useful. It lets you edit lisp code "logically": by atoms
> and sexps, rather than character-by-character. In paredit, the command
> `paredit-splice-sexp-killing-backward' would do what you want, it's
> bound to M-<up>.
> 
> HTH,
  That's the one I'm looking for, I'm sure. Will install. Thank you.
  cheers
-- 
Tim Johnson
http://www.tj49.com

Re: Remove sexp without deleting contents

[Marcin Borkowski]

http://oremacs.com/lispy/

Hth,

On 2018-09-30, at 00:31, Tim Johnson <tim@akwebsoft.com> wrote:

> This poses a rather trivial question, but I'm betting on some
> seredipity from responses.
>
> Suppose I want to remove an extraneous sexp. The following code
> is simplistic:
> (defun tj-toggle-menu-visible ()
>   "Toggle visibility of menu bar and switches to tmm-style menus"
>   (interactive)
>   (if tj-menu-visible
>       (progn
> 	    (setq tj-menu-visible nil)
> 	    (menu-bar-mode -1)
> 	    (setq tj-is-windows nil))
>     (progn
>       (setq tj-menu-visible t)
>       (menu-bar-mode 1)
>       (setq tj-is-windows window-system))))
>
> ;; Suppose I want to remove the second `progn form, but not the
> enclosed sequences. In this simple block of code of code it's pretty
> hard to screw up: just delete/kill the line with "(progn" and any
> right parens from the last line. In a more complex example I might
> delete a parens whose absence could introduce unexpected and
> problematic side effects.
>
> Is there function that might (effectively) simultaneously remove the
> beginning of sexp and the matching closing paren, leaving inner
> contents intact?
>
> thanks.


-- 
Marcin Borkowski
http://mbork.pl