same data appears twice, interactive then function body

same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

Check out this code, how do you avoid having 80 appear twice?

(defun insert-string-centered (string &optional width)
  (interactive
   (list (read-from-minibuffer "string: ")
         (string-to-number (read-from-minibuffer "width [80]: "))) )
  (let*((max         (if (< 0 width) width 80))
        (str-len     (length string))
        (padding     (+ (/ (- max str-len) 2) (if (= 0 (mod str-len 2)) 1 0)))
        (padding-str (make-string padding ?\s)) )
    (insert padding-str string) ))

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Re: same data appears twice, interactive then function body

[Stefan Monnier]

> Check out this code, how do you avoid having 80 appear twice?

> (defun insert-string-centered (string &optional width)
>   (interactive
>    (list (read-from-minibuffer "string: ")
>          (string-to-number (read-from-minibuffer "width [80]: "))) )
>   (let*((max         (if (< 0 width) width 80))
> [...]

Here's my take on it:

    (defun insert-string-centered (string &optional width)
      (interactive
       (list (read-from-minibuffer "string: ")
             (string-to-number (read-from-minibuffer "width [80]: "))) )
      (let*((max         (if (< 0 width) width (+ 42 42 -4)))
    [...]

Now the question is how to avoid having 42 appear twice, I guess,


        Stefan

Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

Stefan Monnier wrote:

> Here's my take on it:
>
>     (defun insert-string-centered (string &optional width)
>       (interactive
>        (list (read-from-minibuffer "string: ")
>              (string-to-number (read-from-minibuffer "width [80]: "))) )
>       (let*((max         (if (< 0 width) width (+ 42 42 -4)))
>     [...]
>
> Now the question is how to avoid having 42 appear twice,
> I guess

Ha :)

No but do tell!

Maybe it can't be done, even?

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Re: same data appears twice, interactive then function body

[2QdxY4RzWzUUiLuE]

On 2020-12-16 at 05:02:36 +0100,
Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org> wrote:

> Stefan Monnier wrote:
> 
> > Here's my take on it:
> >
> >     (defun insert-string-centered (string &optional width)
> >       (interactive
> >        (list (read-from-minibuffer "string: ")
> >              (string-to-number (read-from-minibuffer "width [80]: "))) )
> >       (let*((max         (if (< 0 width) width (+ 42 42 -4)))
> >     [...]
> >
> > Now the question is how to avoid having 42 appear twice,
> > I guess
> 
> Ha :)
> 
> No but do tell!
> 
> Maybe it can't be done, even?

That depends on the unspecified requirements and constraints).

What about a defvar outside the function (completely untested)?

(defvar *default-width* 80
  "default width")
(defun insert-string-centered (string &optional width)
  (interactive
    (list (read-from-minibuffer "string: ")
          (string-to-number
            (read-from-minibuffer
              (format "width [%d]: " *max-width*)))))
  (let* ((max (if (< 0 width) width *default-width*)))
    ...))

Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

2QdxY4RzWzUUiLuE wrote:

> What about a defvar outside the function (completely
> untested)?
>
> (defvar *default-width* 80
>   "default width")

:)

BTW one is discouraged from using that *cl-convention*
in Emacs.

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Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

(defun insert-string-center (string &optional width)
  (interactive
   (list (read-from-minibuffer "string: ")
         (string-to-number (read-from-minibuffer (format "width [%s]: " (window-text-width))))) )
  (let*((max         (if (< 0 width) width (window-text-width)))
        (str-len     (length string))
        (padding     (+ (/ (- max str-len) 2) (if (= 0 (mod str-len 2)) 1 0)))
        (padding-str (make-string padding ?\s)) )
    (insert padding-str string) ))

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Re: same data appears twice, interactive then function body

[Jean Louis]

* Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org> [2020-12-16 07:03]:
> Stefan Monnier wrote:
> 
> > Here's my take on it:
> >
> >     (defun insert-string-centered (string &optional width)
> >       (interactive
> >        (list (read-from-minibuffer "string: ")
> >              (string-to-number (read-from-minibuffer "width [80]: "))) )
> >       (let*((max         (if (< 0 width) width (+ 42 42 -4)))
> >     [...]
> >
> > Now the question is how to avoid having 42 appear twice,
> > I guess

I remember from micro computers that we used division in this way
to find the center.

(defun insert-centered-text (text &optional width)
  (interactive "MText: ")
  (let* ((width (or width (window-text-width)))
	 (length (length (string-trim text)))
	 (pos (/ (- width length) 2)))
    (move-to-column pos t)
    (insert text)
    (insert "\n")))

Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

Jean Louis wrote:

> (defun insert-centered-text (text &optional width)
>   (interactive "MText: ")
>   (let* ((width (or width (window-text-width)))
> 	 (length (length (string-trim text)))
> 	 (pos (/ (- width length) 2)))
>     (move-to-column pos t)
>     (insert text)
>     (insert "\n")))

Oh, so there is a `window-text-width'!

Great, that will do!

Thanks!

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https://dataswamp.org/~incal

Re: same data appears twice, interactive then function body

[Yuri Khan]

On Wed, 16 Dec 2020 at 11:35, Emanuel Berg via Users list for the GNU
Emacs text editor <help-gnu-emacs@gnu.org> wrote:

> Oh, so there is a `window-text-width'!

Depending on what you are trying to achieve, ‘fill-column’ might fit better.

Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

Yuri Khan wrote:

>> Oh, so there is a `window-text-width'!
>
> Depending on what you are trying to achieve, ‘fill-column’
> might fit better.

It works great! I realized you don't even need
`window-text-width' twice! [improved code last]

I use this with files like this:

  https://dataswamp.org/~incal/FILM

(defun insert-string-centered (string &optional width)
  (interactive
   (list (read-from-minibuffer "string: ")
         (string-to-number (read-from-minibuffer "width [window]: " ))))
  (let*((max         (if (< 0 width) width (window-text-width)))
        (str-len     (length string))
        (padding     (- (/ (- max str-len) 2)
                        (if (= 0 (mod str-len 2)) 1 0)) )
        (padding-str (make-string padding ?\s)) )
    (insert padding-str string) ))
(defalias 'isc #'insert-string-centered)

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https://dataswamp.org/~incal

Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

Technologist Adams was kind enough to write me a private mail
telling me my function `insert-string-centered' didn't work
when used from Lisp. Well, that's what I think anyway, since
I received it in my mailbox with no reference in the headers
to either gmane.emacs.help or help-gnu-emacs@gnu.org, and it
doesn't seem to be anywhere else to be found, either!

Probably, he wanted to save me from being all embarrassed in
from of everyone. Well, that was kind! But no worries!
Actually, and to be frank about it, this isn't the first
mistake I ever ever made as a programmer...

Anyway here is a new version, that God willing will work even
under such severe circumstances...

(defun insert-string-centered (str &optional width)
  (interactive
   (list (read-from-minibuffer "string: ")
         (string-to-number (read-from-minibuffer "width [window]: " )) ))
  (let*((span    (if (and width (< 0 width)) width (window-text-width)))
        (str-len (length str))
        (pad     (- (/ (- span str-len) 2)
                    (if (zerop (mod str-len 2)) 1 0) ))
        (pad-str (make-string pad ?\s)) )
    (insert pad-str str) ))
(defalias 'isc #'insert-string-centered)

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https://dataswamp.org/~incal

RE: same data appears twice, interactive then function body

[Drew Adams]

> Technologist Adams was kind enough to write me a private mail

Apologies, but that was only by accident.  As mentioned
earlier, when I use Reply All to reply to your messages
to an Emacs mailing list, the To field has only your name,
and the Cc field is blank.  I have to remember that when
replying to you I need to manually add the mailing list
to the Cc or To field.

IOW, nothing special intended.  I'm no expert in email,
and I'm not about to try reconfiguring my email client.

> telling me my function `insert-string-centered' didn't work
> when used from Lisp. Well, that's what I think anyway, since
> I received it in my mailbox with no reference in the headers
> to either gmane.emacs.help or help-gnu-emacs@gnu.org, and it
> doesn't seem to be anywhere else to be found, either!
>
> Probably, he wanted to save me from being all embarrassed in
> from of everyone. Well, that was kind! But no worries!
> Actually, and to be frank about it, this isn't the first
> mistake I ever ever made as a programmer...

See above for the (mundane) explanation.

Re: same data appears twice, interactive then function body

[Jean Louis]

* Drew Adams <drew.adams@oracle.com> [2020-12-18 19:38]:
> > Technologist Adams was kind enough to write me a private mail
> 
> Apologies, but that was only by accident.  As mentioned
> earlier, when I use Reply All to reply to your messages
> to an Emacs mailing list, the To field has only your name,
> and the Cc field is blank.  I have to remember that when
> replying to you I need to manually add the mailing list
> to the Cc or To field.

While using mutt I do not get Emmanuel's email address but I get the
Emacs mailing list email address. I use g for group reply.

And I can press L for list reply option.

I find his setup alright if one wants to reply to the list, and not to
duplicate emails. I get bunch of duplicate emails that way.

Re: same data appears twice, interactive then function body

[Jean Louis]

* Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org> [2020-12-18 17:51]:
> Technologist Adams was kind enough to write me a private mail
> telling me my function `insert-string-centered' didn't work
> when used from Lisp. Well, that's what I think anyway, since
> I received it in my mailbox with no reference in the headers
> to either gmane.emacs.help or help-gnu-emacs@gnu.org, and it
> doesn't seem to be anywhere else to be found, either!
> 
> Probably, he wanted to save me from being all embarrassed in
> from of everyone. Well, that was kind! But no worries!
> Actually, and to be frank about it, this isn't the first
> mistake I ever ever made as a programmer...
> 
> Anyway here is a new version, that God willing will work even
> under such severe circumstances...
> 
(defun insert-string-centered (str &optional width)
  (interactive
   (list (read-from-minibuffer "string: ")
         (string-to-number (read-from-minibuffer "width [window]: " )) ))
  (let*((span    (if (and width (< 0 width)) width (window-text-width)))
        (str-len (length str))
        (pad     (- (/ (- span str-len) 2)
                    (if (zerop (mod str-len 2)) 1 0) ))
        (pad-str (make-string pad ?\s)) )
    (insert pad-str str) ))
(defalias 'isc #'insert-string-centered)

Look:
(insert-string-centered "Hello")                                        Hello

Do you see how it will not center text as it will be influenced by the
cursor position? It should not be influenced by cursor position. 

Question is what means "centered". Does it mean centered to the width
of text or to the width of the window.

There is function (current-fill-column) that will tell what is the
width of the text. Maybe this is what user expects to be centered.

This one here is using `move-to-column' so because of that it is not
influenced by the cursor position.
                                         
(defun insert-centered-text (text &optional width)
  (interactive "MText: ")
  (let* ((width (or width (window-text-width)))
         (length (length (string-trim text)))
         (pos (/ (- width length) 2)))
    (move-to-column pos t)	     
    (insert text)
    (insert "\n")))

And this one here will consider (current-fill-column) to be the
authoritative width.

(defun insert-centered-text (text &optional width)
  (interactive "MText: ")
  (let* ((width (or width (current-fill-column)))
         (length (length (string-trim text)))
         (pos (/ (- width length) 2)))
    (move-to-column pos t)	     
    (insert text)
    (insert "\n")))

Re: same data appears twice, interactive then function body

[Emanuel Berg via Users list for the GNU Emacs text editor]

Jean Louis wrote:

> Do you see how it will not center text as it will be
> influenced by the cursor position? It should not be
> influenced by cursor position.

I don't know actually ... shouldn't it? This is more versatile
so I'll keep it. But so far, I've only had use of
it interactively.

> Question is what means "centered". Does it mean centered to
> the width of text or to the width of the window.

You set what it means with the width argument :) [1]

It is used for files like this:

  https://dataswamp.org/~incal/FILM

[1] https://dataswamp.org/~incal/emacs-init/edit.el line 11

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