GNU bug report logs - #18909
24.4.50; unexpected (prin1-to-string '(foo "bar") t)

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 18909 in the body.
You can then email your comments to 18909 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Oleh <ohwoeowho <at> gmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 24.4.50; unexpected (prin1-to-string '(foo "bar") t)
Date: Thu, 30 Oct 2014 17:58:39 +0100

Hi,

To my surprise,

    (prin1-to-string '(foo "bar") t)

evaluates as "(foo bar)". This seems like a bug to me, since it doesn't
conform to the doc (it's not the printed representation of the OBJECT any more).

I want to use the NOESCAPE option to obtain instead of:

    (prin1-to-string '(foo.bar)) => "(foo\\.bar)"

this output:

    (prin1-to-string '(foo.bar) t) => "(foo.bar)"

But the downside is that the strings are unquoted as well:

    (prin1-to-string '(foo "bar") t) => "(foo bar)"

Please let me know if it's a bug or not, and maybe suggest how I can
obtain the behavior of (prin1-to-string x t) without unquoting the strings in x.

regards,
Oleh

Message #8 received at 18909 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Oleh <ohwoeowho <at> gmail.com>
Cc: 18909 <at> debbugs.gnu.org
Subject: Re: bug#18909: 24.4.50; unexpected (prin1-to-string '(foo "bar") t)
Date: Fri, 31 Oct 2014 14:16:27 -0400

I don't think you can get what you want with the current code.
The best you can do is (prin1-to-string '(foo.bar "baz")) and then
do a search-and-replace of the "\\.".  But note that the "." is escaped
this way in order to avoid ambiguity with the "." used to separate the
car from the cdr of a cons cell, so you should not unescape every single
"\\.", only the ones where the reader recognizes the "." has being part
of the symbol.


        Stefan

Message #11 received at 18909 <at> debbugs.gnu.org (full text, mbox):

From: Andreas Schwab <schwab <at> linux-m68k.org>
To: Oleh <ohwoeowho <at> gmail.com>
Cc: 18909 <at> debbugs.gnu.org
Subject: Re: bug#18909: 24.4.50; unexpected (prin1-to-string '(foo "bar") t)
Date: Fri, 31 Oct 2014 20:21:00 +0100

Oleh <ohwoeowho <at> gmail.com> writes:

> To my surprise,
>
>     (prin1-to-string '(foo "bar") t)
>
> evaluates as "(foo bar)". This seems like a bug to me, since it doesn't
> conform to the doc (it's not the printed representation of the OBJECT any more).

"This function outputs quoting characters when necessary to make output
that `read' can handle, whenever possible, unless the optional second
argument NOESCAPE is non-nil."

Escaping is about _all_ quotation, not only the backslash.  It's the
difference between prin1 and princ.

Andreas.

-- 
Andreas Schwab, schwab <at> linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Message #14 received at 18909 <at> debbugs.gnu.org (full text, mbox):

From: Noam Postavsky <npostavs <at> users.sourceforge.net>
To: Andreas Schwab <schwab <at> linux-m68k.org>
Cc: Oleh <ohwoeowho <at> gmail.com>, 18909 <at> debbugs.gnu.org
Subject: Re: bug#18909: 24.4.50; unexpected (prin1-to-string '(foo "bar") t)
Date: Fri, 09 Feb 2018 22:10:56 -0500

tags 18909 notabug
close 18909
quit

Andreas Schwab <schwab <at> linux-m68k.org> writes:

> Oleh <ohwoeowho <at> gmail.com> writes:
>
>> To my surprise,
>>
>>     (prin1-to-string '(foo "bar") t)
>>
>> evaluates as "(foo bar)". This seems like a bug to me, since it doesn't
>> conform to the doc (it's not the printed representation of the OBJECT any more).
>
> "This function outputs quoting characters when necessary to make output
> that `read' can handle, whenever possible, unless the optional second
> argument NOESCAPE is non-nil."
>
> Escaping is about _all_ quotation, not only the backslash.  It's the
> difference between prin1 and princ.

Therefore closing as notabug.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.