favorite subject DWIM

favorite subject DWIM

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

I've done this so many times each time doing it in a slightly
different way (I'm sure) so I thought one would do an "ideal"
DWIM function and find out once for all how to do it...

So instead of "(list bg ed)", do something funkadelic...

?

;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;;   https://dataswamp.org/~incal/public_html/emacs-init/dwim.el

(defun test-dwim (&optional beg end)
  (interactive (when (use-region-p)
                 (list (region-beginning) (region-end)) ))
  (let ((bg (or beg (point-min)))
        (ed (or end (point-max))) )
    (list bg ed) ))

(when nil
  (progn
    (set-mark 10)
    (forward-line 3)
    (call-interactively #'test-dwim) ) ; (10 500)

  (call-interactively #'test-dwim)     ; ( 1 604)

  (test-dwim 30 100)                   ; (30 100)

  (test-dwim)                          ; ( 1 604)
)

-- 
underground experts united
https://dataswamp.org/~incal

Re: favorite subject DWIM

[Abhiseck Paira]

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> ;;; -*- lexical-binding: t -*-
> ;;;
> ;;; this file:
> ;;;   https://dataswamp.org/~incal/public_html/emacs-init/dwim.el

This file is not found (404).

> (defun test-dwim (&optional beg end)
>   (interactive (when (use-region-p)
>                  (list (region-beginning) (region-end)) ))
>   (let ((bg (or beg (point-min)))
>         (ed (or end (point-max))) )
>     (list bg ed) ))

Why do you have interactive declaration? The return value (list bg
ed) totally useless to user. Wouldn't most of the time this function be
called by some other function?

Nit-picking: I think the let form is unnecessary.

(defun test-dwim (&optional beg end)
  (interactive (when (use-region-p)
                 (list (region-beginning) (region-end))))
  (list (or beg (point-min))
        (or end (point-max))))

> (when nil
>   (progn
>     (set-mark 10)
>     (forward-line 3)
>     (call-interactively #'test-dwim) ) ; (10 500)
>
>   (call-interactively #'test-dwim)     ; ( 1 604)
>
>   (test-dwim 30 100)                   ; (30 100)
>
>   (test-dwim)                          ; ( 1 604)
> )

Since I couldn't find your file, I may be lacking context, what it seems
here you're testing the function?


-- 
Abhiseck Paira
E34E 825B 979E EB9F 8505  F80E E93D 353B 7740 0709
https://social.linux.pizza/@redstarfish

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Re: favorite subject DWIM

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

Abhiseck Paira wrote:

>> ;;; -*- lexical-binding: t -*-
>> ;;;
>> ;;; this file:
>> ;;;   https://dataswamp.org/~incal/public_html/emacs-init/dwim.el
>
> This file is not found (404).

You are right, here is the correct URL:

  https://dataswamp.org/~incal/emacs-init/dwim.el

I still yank the whole file, last.

>> (defun test-dwim (&optional beg end)
>>   (interactive (when (use-region-p)
>>                  (list (region-beginning) (region-end)) ))
>>   (let ((bg (or beg (point-min)))
>>         (ed (or end (point-max))) )
>>     (list bg ed) ))
>
> Why do you have interactive declaration? [...] Wouldn't most
> of the time this function be called by some other function?

It depends on the actual function but since it involves the
region it is probably used most often interactively.

> Nit-picking: I think the let form is unnecessary.

Here the values are only returned but one can think of more
complicated stuff where the values are used repeatedly.

But actually it isn't a bad thing to be clear about that step
and get it over first thing, it is needed for the &optional
arguments which will be nil if called from Lisp
without arguments.

>> (when nil
>>   (progn
>>     (set-mark 10)
>>     (forward-line 3)
>>     (call-interactively #'test-dwim) ) ; (10 500)
>>
>>   (call-interactively #'test-dwim)     ; ( 1 604)
>>
>>   (test-dwim 30 100)                   ; (30 100)
>>
>>   (test-dwim)                          ; ( 1 604)
>> )
>
> Since I couldn't find your file, I may be lacking context,
> what it seems here you're testing the function?

Yes, as you see it can be used with a region, without a region
(whole buffer acted upon - DWIM), with arguments from Lisp,
and without - in which case again the whole buffer will be
used, so the interactive/no-region is analogous to
from-Lisp/no-arguments.

DWIM!

;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;;   https://dataswamp.org/~incal/emacs-init/dwim.el

(defun test-dwim (&optional beg end)
  (interactive (when (use-region-p)
                 (list (region-beginning) (region-end)) ))
  (let ((bg (or beg (point-min)))
        (ed (or end (point-max))) )
    (list bg ed) ))

(when nil
  (progn
    (set-mark 10)
    (forward-line 3)
    (call-interactively #'test-dwim) ) ; (10 500)

  (call-interactively #'test-dwim)     ; ( 1 604)

  (test-dwim 30 100)                   ; (30 100)

  (test-dwim)                          ; ( 1 604)
)

-- 
underground experts united
https://dataswamp.org/~incal