bug#49376: Feature request (poll): default function for pretty printing when called interactively

bug#49376: Feature request (poll): default function for pretty printing when called interactively

[dalanicolai]

I find myself quite frequently prefering to use the following form for
exiting/returning from a function:
```
        (when (called-interactively-p)
          (pp some-datastructure)
          data-structure))))
```
because often I prefer to see a pretty printed representation of a
data-structure when calling as a command, while I would like to use the
data-structure in another function when called as a function (which
unfortunately is not possible with the pretty printed data-structure)

So I was wondering if it would be reasonable to add a basic output
function for this to the Emacs core. Not very important of course, but
I figured that it could be a reasonable addition. If anybody has a
strong opinion about it, please share. Thank you!

bug#49376: Feature request (poll): default function for pretty printing when called interactively

[dalanicolai]

It is mainly useful when parsing text/code/buffers, so it might be
called parse<->print (<-> means optionally interchanged). On the other
hand it is used mainly when "developing" (or when transforming
text/code), so it might be called devel<->print.
Obviously it is no problem to just define this function in my
package(s), where I like to provide users with an 'even easier'
introspection option for some 'reusable' functions (e.g. parsing a pdf
to a dom (html/xml). Where we often want to apply it to the currently
viewed document).

bug#49376:

[dalanicolai]

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I guess it should actually be the following macro, to function as it is
supposed to:
```
(defmacro parse-print (data)
  `(if (called-interactively-p)
       (pp ,data)
    ,data))
```

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bug#49376: Feature request (poll): default function for pretty printing when called interactively

[Lars Ingebrigtsen]

dalanicolai@gmail.com writes:

> So I was wondering if it would be reasonable to add a basic output
> function for this to the Emacs core.

I can't quite remember writing any command that would pretty-print a
Lisp expression when called interactively -- when a command displays
information to the user, pp-ing a Lisp expression is usually not the
most readable way.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#49376: Feature request (poll): default function for pretty printing when called interactively

[dalanicolai]

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I agree it is not that important. But now I do wonder what then, in general,
would provide a more readable way for printing lisp expressions.

On Sun, 4 Jul 2021 at 15:40, Lars Ingebrigtsen <larsi@gnus.org> wrote:

> dalanicolai@gmail.com writes:
>
> > So I was wondering if it would be reasonable to add a basic output
> > function for this to the Emacs core.
>
> I can't quite remember writing any command that would pretty-print a
> Lisp expression when called interactively -- when a command displays
> information to the user, pp-ing a Lisp expression is usually not the
> most readable way.
>
> --
> (domestic pets only, the antidote for overdose, milk.)
>    bloggy blog: http://lars.ingebrigtsen.no
>

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bug#49376: Feature request (poll): default function for pretty printing when called interactively

[Lars Ingebrigtsen]

dalanicolai <dalanicolai@gmail.com> writes:

> I agree it is not that important. But now I do wonder what then, in general,
> would provide a more readable way for printing lisp expressions.

Messaging a Lisp expression at the user is pretty uncommon in itself, I
think?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#49376: Feature request (poll): default function for pretty printing when called interactively

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> dalanicolai <dalanicolai@gmail.com> writes:
>
>> I agree it is not that important. But now I do wonder what then, in general,
>> would provide a more readable way for printing lisp expressions.
>
> Messaging a Lisp expression at the user is pretty uncommon in itself, I
> think?

I think the conclusion here was that we don't really want to add
something like this, so I'm closing this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no