Subject: bug#6891: closed (Re: bug#6891: `string-to-number' doesn't recognize `#'' read syntax)

From: [email-masked] (GNU bug Tracking System)
Date: Wed, 26 Jun 2019 15:17:04 +0000

Your bug report

#6891: `string-to-number' doesn't recognize `#'' read syntax

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
6891: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=6891
GNU Bug Tracking System
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Subject: Re: bug#6891: `string-to-number' doesn't recognize `#'' read syntax
From: Eli Zaretskii <[email-masked]>
To: Lars Ingebrigtsen <[email-masked]>
Cc: [email-masked], [email-masked]
Date: Wed, 26 Jun 2019 18:15:27 +0300
List-Id: <debbugs-submit.debbugs.gnu.org>

> From: Lars Ingebrigtsen <[email-masked]>
> Date: Wed, 26 Jun 2019 13:44:41 +0200
> Cc: [email-masked]
> 
> Stefan Kangas <[email-masked]> writes:
> 
> > This bug was tagged as wontfix three years ago.
> >
> > Is it desirable to close it too?
> 
> I think so.

Agreed and done.

Thanks.

Subject: `string-to-number' doesn't recognize `#'' read syntax
From: MON KEY <[email-masked]>
To: [email-masked]
Date: Fri, 20 Aug 2010 20:01:06 -0400
List-Id: <debbugs-submit.debbugs.gnu.org>

`string-to-number' takes an optional arg BASE but doesn't recognize lisp `#'
read syntax for binary, octal, hex, and radix, e.g.  `#o', `#b', `#x', and
`#<RADIX>r'. It should, these _are_ the respective read syntax for BASE.
For good measure it should also recognize the string output from
`format's `#' flag for octal and hex e.g `0x' for hex and `0' for octal.

The proposed behaviour should not pose a lisp dialect compatiblility problem as
Emacs lisp does not attempt to follow the Common Lisp spec, does not maintain a
duplicate for CL's `parse-integer' procedure and does not take a bounding START
END arg, but _does_ parse floats so it shouldn't be restricted by that specs
constraints w/re the `#' radix read syntax e.g:

,----
| `parse-integer' does not recognize the syntactic radix-specifier
| prefixes `#O', `#B', `#X', and `#nR', nor does it recognize a trailing
| decimal point.
`----

Besides, `string-to-number' already has a BASE argument, the C code already
strips whitespace, discards "junk", and exhibits a willingness to interpolate
sign in sometimes odd ways, so a little more DWIM can't hurt.

Current `string-to-number' DWIMness:
string-to-number "   -3777777777" 8) ;=> 536870911
(string-to-number "   -3777777777.007" 8) ;=> 536870911
(string-to-number "   -3777777777mmm#" 8) ;=> 536870911
(string-to-number "+   -3777777777mmm#" 8) ;=> 0

Following illustrates the additioanl DWIMing desired:

#o
(string-to-number "#o3777777777" 8) ;=> 536870911

#b
(string-to-number "#b11111111111111111111111111111" 2) ;=> 536870911

#x
(string-to-number "#x1fffffff" 16) ;=> 536870911

#<RDX>r
(string-to-number "#12r12B969227" 12) ;=> 536870911

0x
(string-to-number "0x1fffffff" 16) ;=> 536870911

0
(string-to-number "03777777777" 8) ;=> 536870911

--
/s_P\