Deleting a word using keybinding

Deleting a word using keybinding

[Christopher Dimech]

   I am trying to delete a word using keybinding string "C-<tab>" but the
   Chord is still showing as undefined.

   I would like to delete a word even if I happen to be in the middle of
   it., so I move backward.

   Here is the function

   ( global-set-key (kbd "C-<tab>" )
       ( lambda () (interactive)
           ( (backward-word)
             (kill-word 1)
           )
       )
   )

Re: Deleting a word using keybinding

[Jeremie Juste]

Hello,

To investigate I usually separate the problem into two parts
Frist the key binding and second the function.

The function test work as you expect when calling M-x test

(defun test ()
  (interactive)
       (progn  (backward-word)
	       (kill-word 1)) )

(global-set-key (kbd "C-<tab>") 'test)

For the keybinding I guess it will depend on the mode you are in. As tab
is intensively used so a minor mode might take control of it if I
understand correctly. A way to test it would be to test the binding in
fundamental-mode.

HTH,
Jeremie

Re: Deleting a word using keybinding

[Harald Jörg]

On 10/15/20 12:26 PM, Christopher Dimech wrote:
 >
 > I am trying to delete a word using keybinding string "C-<tab>" but the
 > Chord is still showing as undefined.
 >
 > I would like to delete a word even if I happen to be in the middle of
 > it., so I move backward.
 >
 >     Here is the function
 >
 >     ( global-set-key (kbd "C-<tab>" )
 >         ( lambda () (interactive)
 >             ( (backward-word)
 >               (kill-word 1)
 >             )
 >         )
 >     )

If I get rid of one pair of parens, it works for me.

( global-set-key (kbd "C-<tab>" )
        ( lambda () (interactive)
            (backward-word)
            (kill-word 1)
        )
    )

With the extra parens in your code, I get 'Invalid function:
(backward-word)'.  Maybe this is why you don't see any effect?

Also note that if your point happens to be on the first character of a
word, this function deletes the _previous_ word.
-- 
Cheers,
haj

Re: Deleting a word using keybinding

[Christopher Dimech]

   Dear Haj, correct, if I happen toi be at the beginning of a word, it
   deletes the previous word.
   I would like to have it kill forward, so I modified as follows

   ( global-set-key (kbd "H-<delete>" )
       ( lambda () (interactive)
           (forward-word)
           (kill-word 1)
           (message "**** Killing a word")

       )
   )

   A small remaining part to to kill the whole word even if I am in the
   middle of a word,
   because my code only deletes from the current point onwards.

   Sent: Thursday, October 15, 2020 at 1:20 PM
   From: "Harald Jörg" <haj@posteo.de>
   To: "Christopher Dimech" <dimech@gmx.com>, "Help Gnu Emacs"
   <help-gnu-emacs@gnu.org>
   Subject: Re: Deleting a word using keybinding
   On 10/15/20 12:26 PM, Christopher Dimech wrote:
   >
   > I am trying to delete a word using keybinding string "C-<tab>" but
   the
   > Chord is still showing as undefined.
   >
   > I would like to delete a word even if I happen to be in the middle of
   > it., so I move backward.
   >
   > Here is the function
   >
   > ( global-set-key (kbd "C-<tab>" )
   > ( lambda () (interactive)
   > ( (backward-word)
   > (kill-word 1)
   > )
   > )
   > )
   If I get rid of one pair of parens, it works for me.
   ( global-set-key (kbd "C-<tab>" )
   ( lambda () (interactive)
   (backward-word)
   (kill-word 1)
   )
   )
   With the extra parens in your code, I get 'Invalid function:
   (backward-word)'. Maybe this is why you don't see any effect?
   Also note that if your point happens to be on the first character of a
   word, this function deletes the _previous_ word.
   --
   Cheers,
   haj

Re: Deleting a word using keybinding

[Christopher Dimech]

   I have updated my function to kill words forward so that even if I am
   in the middle
   of a word that word will be killed. I also consider that if there are
   multiple spaces, I
   delete just the spaces spaces but not next word.

   I am finding a problem however when deleting part of a sentence by
   contiuing to press
   C--<delete> because when the point happens to be between two words, I
   end up with the
   two words  stuck together (the previous and thn forward), which deletes
   the two words
   when I hit C-<delete> again.

   (defun kill-spacword ()
      (interactive)
      (if (looking-at "[ \t\n]")
         (let ((p (point)))
            ( re-search-forward "[^ \t\n]" nil :no-error )
            ( backward-char )
            ( kill-region p (point) )
         )
         ( progn
            (backward-char)
            (if (looking-at "[ \t\n]")
               (kill-word 1)
               ( progn
                   (backward-word)
                   (kill-word 1)
               )
            )
         )
      )
   )





   Sent: Thursday, October 15, 2020 at 1:20 PM
   From: "Harald Jörg" <haj@posteo.de>
   To: "Christopher Dimech" <dimech@gmx.com>, "Help Gnu Emacs"
   <help-gnu-emacs@gnu.org>
   Subject: Re: Deleting a word using keybinding
   On 10/15/20 12:26 PM, Christopher Dimech wrote:
   >
   > I am trying to delete a word using keybinding string "C-<tab>" but
   the
   > Chord is still showing as undefined.
   >
   > I would like to delete a word even if I happen to be in the middle of
   > it., so I move backward.
   >
   > Here is the function
   >
   > ( global-set-key (kbd "C-<tab>" )
   > ( lambda () (interactive)
   > ( (backward-word)
   > (kill-word 1)
   > )
   > )
   > )
   If I get rid of one pair of parens, it works for me.
   ( global-set-key (kbd "C-<tab>" )
   ( lambda () (interactive)
   (backward-word)
   (kill-word 1)
   )
   )
   With the extra parens in your code, I get 'Invalid function:
   (backward-word)'. Maybe this is why you don't see any effect?
   Also note that if your point happens to be on the first character of a
   word, this function deletes the _previous_ word.
   --
   Cheers,
   haj

Re: Deleting a word using keybinding

[Harald Jörg]

On 10/15/20 8:44 PM, Christopher Dimech wrote:

 > I have updated my function to kill words forward so that even if I am
 > in the middle of a word that word will be killed. I also consider that
 > if there are multiple spaces, I delete just the spaces spaces but not
 > next word.

This isn't exactly what the function does: If there are two or more
spaces between words, then only spaces to the right of point are
deleted.

Also, when you delete _all_ spaces, you merge two words into one.  This
is the cause for your observation:

 > I am finding a problem however when deleting part of a sentence by
 > contiuing to press C--<delete> because when the point happens to be
 > between two words, I end up with the two words stuck together (the
 > previous and thn forward), which deletes the two words when I hit
 > C-<delete> again.

It really pays off when you spend the effort to write down how you
want the function to behave in all relevant situations.  It is good
practice to have a docstring for your command anyway, and you might
detect contradictory requirements before you start writing the
function.

If point is before a whitespace character, you could either do
nothing, or delete the previous, or delete the following word, all of
them make some sense.  Deleting whitespace seems somewhat unrelated.

There still are cases where your function does not what you seem to
expect: If the text in the buffer is "foo bar", and point is before
the "a" in "bar", then executing M-x kill-spacword kills "foo".
--
Cheers,
haj

Re: Deleting a word using keybinding

[Christopher Dimech]

     I want it to behave as C-<delete>, except that I want to delete the
   current word if
   the cursor happens to be within a word.
   For instance,  consider the following sentence. I want that
   if the cursor point in on the character w of the word Brown,
   the word Brown is also deleted, rather than deleting the word fromw
   onwards.
   The Brown Fox Jumped a Fence
   I also would like that when there are multiple space, I first delete
   the spaces
   and leave just one space rather than deleting the next word.



   Sent: Thursday, October 15, 2020 at 10:25 PM
   From: "Harald Jörg" <haj@posteo.de>
   To: "Christopher Dimech" <dimech@gmx.com>
   Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
   Subject: Re: Deleting a word using keybinding
   On 10/15/20 8:44 PM, Christopher Dimech wrote:
   > I have updated my function to kill words forward so that even if I am
   > in the middle of a word that word will be killed. I also consider
   that
   > if there are multiple spaces, I delete just the spaces spaces but not
   > next word.
   This isn't exactly what the function does: If there are two or more
   spaces between words, then only spaces to the right of point are
   deleted.
   Also, when you delete _all_ spaces, you merge two words into one. This
   is the cause for your observation:
   > I am finding a problem however when deleting part of a sentence by
   > contiuing to press C--<delete> because when the point happens to be
   > between two words, I end up with the two words stuck together (the
   > previous and thn forward), which deletes the two words when I hit
   > C-<delete> again.
   It really pays off when you spend the effort to write down how you
   want the function to behave in all relevant situations. It is good
   practice to have a docstring for your command anyway, and you might
   detect contradictory requirements before you start writing the
   function.
   If point is before a whitespace character, you could either do
   nothing, or delete the previous, or delete the following word, all of
   them make some sense. Deleting whitespace seems somewhat unrelated.
   There still are cases where your function does not what you seem to
   expect: If the text in the buffer is "foo bar", and point is before
   the "a" in "bar", then executing M-x kill-spacword kills "foo".
   --
   Cheers,
   haj

Re: Deleting a word using keybinding

[Thien-Thi Nguyen]

[-- Attachment #1: Type: text/plain, Size: 565 bytes --]

() Christopher Dimech <dimech@gmx.com>
() Thu, 15 Oct 2020 22:59:29 +0200

   and leave just one space rather than [...]

There's a command for that -- can you guess its name?  :-D

-- 
Thien-Thi Nguyen -----------------------------------------------
 (defun responsep (query)               ; (2020) Software Libero
   (pcase (context query)               ;       = Dissenso Etico
     (`(technical ,ml) (correctp ml))
     ...))                              748E A0E8 1CB8 A748 9BFA
--------------------------------------- 6CE4 6703 2224 4C80 7502


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 219 bytes --]

Re: Deleting a word using keybinding

[Christopher Dimech]

   Got it (just-one-space)

   Sent: Thursday, October 15, 2020 at 11:06 PM
   From: "Thien-Thi Nguyen" <ttn@gnuvola.org>
   To: "Christopher Dimech" <dimech@gmx.com>
   Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
   Subject: Re: Deleting a word using keybinding
   () Christopher Dimech <dimech@gmx.com>
   () Thu, 15 Oct 2020 22:59:29 +0200
   and leave just one space rather than [...]
   There's a command for that -- can you guess its name? :-D
   --
   Thien-Thi Nguyen -----------------------------------------------
   (defun responsep (query) ; (2020) Software Libero
   (pcase (context query) ; = Dissenso Etico
   (`(technical ,ml) (correctp ml))
   ...)) 748E A0E8 1CB8 A748 9BFA
   --------------------------------------- 6CE4 6703 2224 4C80 7502

Re: Deleting a word using keybinding

[Christopher Dimech]

   Is there a way to detect end of buffer?

   Sent: Thursday, October 15, 2020 at 11:14 PM
   From: "Christopher Dimech" <dimech@gmx.com>
   To: "Thien-Thi Nguyen" <ttn@gnuvola.org>
   Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
   Subject: Re: Deleting a word using keybinding
   Got it (just-one-space)
   Sent: Thursday, October 15, 2020 at 11:06 PM
   From: "Thien-Thi Nguyen" <ttn@gnuvola.org>
   To: "Christopher Dimech" <dimech@gmx.com>
   Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
   Subject: Re: Deleting a word using keybinding
   () Christopher Dimech <dimech@gmx.com>
   () Thu, 15 Oct 2020 22:59:29 +0200
   and leave just one space rather than [...]
   There's a command for that -- can you guess its name? :-D
   --
   Thien-Thi Nguyen -----------------------------------------------
   (defun responsep (query) ; (2020) Software Libero
   (pcase (context query) ; = Dissenso Etico
   (`(technical ,ml) (correctp ml))
   ...)) 748E A0E8 1CB8 A748 9BFA
   --------------------------------------- 6CE4 6703 2224 4C80 7502

RE: Deleting a word using keybinding

[Drew Adams]

>    Is there a way to detect end of buffer?

Function `eobp'

Re: RE: Deleting a word using keybinding

[Christopher Dimech]

   I have made some imporvement.  Been using the following text for
   testing, and when I am
   getting a comma, dash, or period, the function is deleting backwards.
   When this happens
   I just want it to behave as (kill-word)

   ;; This buffer is for text that is not saved, and for Lisp evaluation.
   ;; To create a file, visit it with C-x C-f and enter text in its
   buffer.

   (defun kill-spacword ()
     "Kills Word forward including Current Word.
   Multiple Spaces are reduced to one space, but without deleting
   next word."
     (interactive)
       (if (looking-at "[ \t\n]")
          ;; Space detected.
          (progn
             (forward-char)
             (if (looking-at "[ \t\n]")
               (just-one-space)
               (progn (backward-char) (kill-word 1) )
            )
          )
          ;; Current Point found on a word
          ( progn
              (if (eobp)
                 nil
                 ;;(progn (backward-word) (kill-word 1))
                 (progn
                   (backward-char)
                   (if (looking-at "[ \t\n]")
                      (kill-word 1)
                      (progn (backward-word) (kill-word 1))
                   )
                 )
             )
          )
       )
   )




   Sent: Thursday, October 15, 2020 at 11:27 PM
   From: "Drew Adams" <drew.adams@oracle.com>
   To: "Christopher Dimech" <dimech@gmx.com>
   Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>, "Thien-Thi Nguyen"
   <ttn@gnuvola.org>
   Subject: RE: Deleting a word using keybinding
   > Is there a way to detect end of buffer?
   Function `eobp'

Re: Deleting a word using keybinding

[Stephen Berman]

On Thu, 15 Oct 2020 23:14:05 +0200 Christopher Dimech <dimech@gmx.com> wrote:

>    Got it (just-one-space)
>
>    Sent: Thursday, October 15, 2020 at 11:06 PM
>    From: "Thien-Thi Nguyen" <ttn@gnuvola.org>
>    To: "Christopher Dimech" <dimech@gmx.com>
>    Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
>    Subject: Re: Deleting a word using keybinding
>    () Christopher Dimech <dimech@gmx.com>
>    () Thu, 15 Oct 2020 22:59:29 +0200
>    and leave just one space rather than [...]
>    There's a command for that -- can you guess its name? :-D

You also might find bounds-of-thing-at-point useful for your function.

Steve Berman

Re: Deleting a word using keybinding

[Stephen Berman]

On Thu, 15 Oct 2020 12:26:59 +0200 Christopher Dimech <dimech@gmx.com> wrote:

>    I am trying to delete a word using keybinding string "C-<tab>" but the
>    Chord is still showing as undefined.
>
>    I would like to delete a word even if I happen to be in the middle of
>    it., so I move backward.
>
>    Here is the function
>
>    ( global-set-key (kbd "C-<tab>" )
>        ( lambda () (interactive)
>            ( (backward-word)
>              (kill-word 1)
>            )
>        )
>    )

Other have already shown how to correct your code, but here's some
advice with which you can maybe help yourself in future:

When I evaluate this code and then type `C-<tab>', I see this message:
"Invalid function: (backward-word)".  That tells you what the problem
is.  If you don't understand it, try reading the node "Run a Program" in
the Info manual "An Introduction to Programming in Emacs Lisp", which
you can access by putting the cursor after the closing parenthesis of
the following expression and typing `C-x C-e':

(info "(eintr) Run a Program")

In particular, this part of the node should help you see the problem
with your code:

  The single apostrophe, ‘'’, that I put in front of some of the
  example lists in preceding sections is called a “quote”; when it
  precedes a list, it tells Lisp to do nothing with the list, other than
  take it as it is written.  But if there is no quote preceding a list,
  the first item of the list is special: it is a command for the computer
  to obey.  (In Lisp, these commands are called _functions_.)  The list
  ‘(+ 2 2)’ shown above did not have a quote in front of it, so Lisp
  understands that the ‘+’ is an instruction to do something with the rest
  of the list: add the numbers that follow.

Steve Berman

Re: Deleting a word using keybinding

[Stefan Monnier]

>    I am trying to delete a word using keybinding string "C-<tab>" but the
>    Chord is still showing as undefined.

Try `C-h k C-TAB` and show us what it says.


        Stefan