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

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

[Oleh]

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

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

[Stefan Monnier]

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

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

[Andreas Schwab]

Oleh <ohwoeowho@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@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

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

[Noam Postavsky]

tags 18909 notabug
close 18909
quit

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

> Oleh <ohwoeowho@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.