[debbugs-tracker] bug#13757: closed (Problems with Guile's number printer)

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Your message dated Sun, 17 Mar 2013 21:29:39 -0400
with message-id <address@hidden>
and subject line Re: Problems with Guile's number printer
has caused the debbugs.gnu.org bug report #13757,
regarding Problems with Guile's number printer
to be marked as done.

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13757: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13757
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> --- Begin Message ---
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>
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> Subject: 
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> Problems with Guile's number printer
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>
>
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> Date: 
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> Tue, 19 Feb 2013 09:18:07 +0100
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> User-agent: 
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> Gnus/5.13 (Gnus v5.13) Emacs/24.2 (gnu/linux)
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>
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>
> Hi,
>
> I'm redirecting the number printing conversation to bug-guile, so that
> we can track it.  Thanks for the debugging!
>
> On Tue 19 Feb 2013 00:12, Mark H Weaver <address@hidden> writes:
>
> > Andy Wingo <address@hidden> writes:
> >
> >> On Wed 23 Jan 2013 13:20, Daniel Llorens <address@hidden> writes:
> >>
> >>> scheme@(guile-user)> (f64vector-ref #s64(1 2 3) 0)
> >>> $1 = #.#
> >>
> >> Here you are interpreting an int64 as a double, which should work, but
> >> this printed result is really bizarre and looks like a bug in our number
> >> printer.  Mark? :)
> >
> > Yes, our number printer is seriously flawed and needs a rewrite.  It
> > prints subnormal[1] floats as "#.#", and even in typical cases often
> > fails to print enough digits to get the same number back when you read
> > it back in.
> >
> > Note that this also affects compiled code involving numbers, because the
> > compiler serializes numbers using 'number->string'.  For example,
> > (* 1e-155 1e-155) returns #f at the REPL, because peval turns this into
> > a constant which happens to be a subnormal.  During assembly it serializes
> > this to "#.#", and then 'string->number' returns #f.
> >
> > Also, 3.14159265358979323846264338327950288419716939937510582097494, if
> > compiled, fails to produce the float closest to pi.  (acos -1) works
> > properly, but only because this expression is not currently folded to a
> > constant by the compiler.
> >
> > I've already started work on this (based on "Printing Floating-Point
> > Numbers Quickly and Accurately" by Burger and Dybvig) but got
> > distracted.
> >
> >      Mark
> >
> > [1] http://en.wikipedia.org/wiki/Subnormal_number
>
> -- 
> http://wingolog.org/
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
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> Re: Problems with Guile's number printer
>
>
>
>
> Date: 
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> Sun, 17 Mar 2013 21:29:39 -0400
>
>
>
>
> User-agent: 
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> Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux)
>
>
>
>
> I've pushed 1ea37620c2c1794f7685b312d2530676a078ada7 to stable-2.0,
> which fixes our number printer.  Closing this bug.
>
>    Thanks,
>      Mark
>
>
>
> --- End Message ---