[#41908] [Backport93 - Backport #5844][Open] Can't install ruby-debug-base19 — Brian Osborne <bosborne11@...>
3 messages
2012/01/05
[#41916] Proposal: Bitmap Marking GC — Narihiro Nakamura <authornari@...>
Hi.
18 messages
2012/01/05
[#41919] Re: Proposal: Bitmap Marking GC
— Roger Pack <rogerdpack2@...>
2012/01/05
> And, GC is a little bit slower. But, I think it's in acceptable range.
[#41968] Re: Proposal: Bitmap Marking GC
— Eric Wong <normalperson@...>
2012/01/07
Narihiro Nakamura <[email protected]> wrote:
[#41969] Re: Proposal: Bitmap Marking GC
— KOSAKI Motohiro <kosaki.motohiro@...>
2012/01/07
> Narihiro Nakamura <[email protected]> wrote:
[#41934] feature request: marshallable proc's — Roger Pack <rogerdpack2@...>
Every so often I wish I could do something like
10 messages
2012/01/05
[#41936] Re: feature request: marshallable proc's
— Urabe Shyouhei <shyouhei@...>
2012/01/06
On 2012年01月06日 08:54, Roger Pack wrote:
[#42898] Re: feature request: marshallable proc's
— SASADA Koichi <ko1@...>
2012/02/25
What should happen on the following code?
[#41979] [ruby-trunk - Bug #5865][Open] Exception#== should return false if the classes differ — Hiro Asari <asari.ruby@...>
10 messages
2012/01/08
[#41997] [ruby-trunk - Bug #5865] Exception#== should return false if the classes differ
— Hiro Asari <asari.ruby@...>
2012/01/09
[#42000] Re: [ruby-trunk - Bug #5865] Exception#== should return false if the classes differ
— Yukihiro Matsumoto <matz@...>
2012/01/09
Hi,
[#42002] Re: [ruby-trunk - Bug #5865] Exception#== should return false if the classes differ
— Nikolai Weibull <now@...>
2012/01/09
On Mon, Jan 9, 2012 at 12:43, Yukihiro Matsumoto <[email protected]> wrote=
[#42003] [ruby-trunk - Bug #5871][Open] regexp \W matches some word characters when inside a case-insensitive character class — Gareth Adams <gareth@...>
14 messages
2012/01/09
[#42016] [ruby-trunk - Feature #5873][Open] Adopt FFI over DL — Heesob Park <phasis@...>
15 messages
2012/01/10
[#42035] [ruby-trunk - Feature #5873] Adopt FFI over DL
— Heesob Park <phasis@...>
2012/01/10
[#42125] Re: [ruby-trunk - Feature #5873] Adopt FFI over DL
— Aaron Patterson <tenderlove@...>
2012/01/13
On Tue, Jan 10, 2012 at 10:01:26PM +0900, Heesob Park wrote:
[#42127] Re: [ruby-trunk - Feature #5873] Adopt FFI over DL
— Nobuyoshi Nakada <nobu@...>
2012/01/14
Hi,
[#42129] Re: [ruby-trunk - Feature #5873] Adopt FFI over DL
— KOSAKI Motohiro <kosaki.motohiro@...>
2012/01/14
> To remove original DL completely, we have to bundle libffi itself
[#42042] RUBY 2 RCR: remove Thread#raise — Roger Pack <rogerdpack2@...>
Hello.
6 messages
2012/01/10
[#42061] Re: RUBY 2 RCR: remove Thread#raise
— Eric Wong <normalperson@...>
2012/01/11
Roger Pack <[email protected]> wrote:
[#42049] [ruby-trunk - Bug #5877][Open] Poor performance of initial and final UTF-8 substrings — Nathan Weizenbaum <nex342@...>
4 messages
2012/01/10
[#42063] [ruby-trunk - Bug #5884][Open] Float::NAN and 0.0/0.0 is represented differently when packed with 'g' — Hiro Asari <asari.ruby@...>
9 messages
2012/01/11
[#42080] [ruby-trunk - Bug #5887][Open] The documentation of Module.constants is incorrect — Shugo Maeda <redmine@...>
9 messages
2012/01/12
[#42085] [ruby-trunk - Bug #5888][Open] JSON unittest fails — Vit Ondruch <v.ondruch@...>
13 messages
2012/01/12
[#42093] Backport93 help needed for a few Windows requests? — Jon <jon.forums@...>
Currently the following Windows-specific backport requests to ruby_1_9_3 remain unassigned:
4 messages
2012/01/12
[#42113] [ruby-trunk - Feature #5893][Open] named return,next... — Ondrej Bilka <neleai@...>
7 messages
2012/01/13
[#42114] Re: [ruby-trunk - Feature #5893][Open] named return,next...
— Anurag Priyam <anurag08priyam@...>
2012/01/13
On Fri, Jan 13, 2012 at 7:21 PM, Ondrej Bilka <[email protected]> wrote:
[#42115] Re: [ruby-trunk - Feature #5893][Open] named return,next...
— Ondřej Bílka <neleai@...>
2012/01/13
On Fri, Jan 13, 2012 at 11:11:28PM +0900, Anurag Priyam wrote:
[#42139] [ruby-trunk - Feature #5898][Open] raise and Exception#initialize — Thomas Sawyer <transfire@...>
10 messages
2012/01/16
[#42149] [ruby-trunk - Feature #5899][Open] chaining comparsions. — Ondrej Bilka <neleai@...>
12 messages
2012/01/16
[#42160] [ruby-trunk - Bug #5902][Open] Array#join with an unused, infected separator may or may not infect the result — John Firebaugh <john.firebaugh@...>
8 messages
2012/01/17
[#42164] [ruby-trunk - Feature #5903][Open] Optimize st_table (take 2) — Yura Sokolov <funny.falcon@...>
18 messages
2012/01/17
[#42189] [ruby-trunk - Bug #5914][Open] Calling extend with an anonymous module requires use of parentheses — Mark Somerville <mark@...>
3 messages
2012/01/20
[#42194] [ruby-trunk - Bug #5915][Open] Array#join with explicit nil should not use $, — John Firebaugh <john.firebaugh@...>
10 messages
2012/01/20
[#42222] [ruby-trunk - Bug #5925][Open] Lazy initialization is not thread safe. — Xuân Baldauf <xuan--2009--xbaldauf--redmine.ruby-lang.org@...>
5 messages
2012/01/23
[#42235] [ruby-trunk - Bug #5931][Open] Random SEGV during execution on YARD specs — Vit Ondruch <v.ondruch@...>
9 messages
2012/01/26
[#42246] Fwd: RCR String#{last, first} — Roger Pack <rogerdpack2@...>
Hello.
6 messages
2012/01/27
[#42256] [ruby-trunk - Feature #5945][Open] Add the ability to mark a at_exit as process-local. — Robert Gleeson <rob@...>
4 messages
2012/01/30
[#42257] [Backport93 - Backport #5942][Open] Backport r34309-34310 r34312-32414 — Yura Sokolov <funny.falcon@...>
4 messages
2012/01/30
[#42285] Why Ruby 1.9 GUI hangs if i do any intensive computation in separate Ruby thread? — Grigory Petrov <grigory.v.p@...>
Hello
4 messages
2012/01/31
[#42286] Re: Why Ruby 1.9 GUI hangs if i do any intensive computation in separate Ruby thread?
— "Haase, Konstantin" <Konstantin.Haase@...>
2012/01/31
the GIL is *not* supposed to lift if some threads enters native code...
[ruby-core:42077] [ruby-trunk - Bug #5884] Float::NAN and 0.0/0.0 is represented differently when packed with 'g'
From:
Yui NARUSE <naruse@...>
Date:
2012-01-12 02:14:42 UTC
List:
ruby-core #42077
Issue #5884 has been updated by Yui NARUSE.
Yui NARUSE wrote:
> Hiro Asari wrote:
> > Besides it being status quo, what is the rationale behind not having Float::NAN and 0.0/0.0 act identically?
>
> * I thought it should be quiet NaN
> * no reason to choose "\xFF\xC0\x00\x00" there is many NaNs and platform dependent
> * the result of 0.0/0.0 may differ on each call
I must add one more reason; the NaN seems not what I defined.
The NaN is provided by the system's math.h.
And additional to say, you should use unpack('G') because it is double.
Hiro Asari wrote:
> I am not presenting a real use case. That is not my intent. My intent is to clarify the design of Float::NAN, especially in relation to 0.0/0.0. Since there is no way to distinguish the two without it, it seems to me that Array#pack is as good a use case as any. It is useful to the extent that we can distinguish the two, now that it is established that they can (and perhaps *should*) be different.
The design of Float::NAN is to provide a NaN.
It may equal to a result of 0.0/0.0 as a binary and maybe not.
The reason why there is no straight way to distinguish the two is people shouldn't need it.
> I see that my assumption that these objects should behave the same was flat out misguided.
>
> It is acknowledged that there are many NaN's. As there is no way to distinguish these multiple NaN values that are passed to Array#pack,
If you know the environment's floating point number system supports IEEE 754 and its endian,
you can know what binary is NaN.
> then, am I correct to conclude that [Float::NAN].pack("g"), as well as [0.0/0.0].pack("g"), is indeterminate?
Yes, its binary expression is out of the spec.
The one accurate thing is the binary is a NaN on the environment.
> Also, am I correct to conclude that the value generated on one machine may not be identical to the one that is generated on another?
>
> (I understand that this is mostly academic; the two different values make a round trip correctly in and out of their respective packed counterpart, one way or another.)
Yes, of course.
There is non IEEE 754 systems.
# for example VAX is not an IEEE 754 system and doesn't have NaN. (Ruby 1.9 or later doesn't support it)
And IEEE 754/other specs doesn't say what NaN should be returned.
Anyway if both system is IEEE 754 system, a NaN on a system is also a NaN on another system.
----------------------------------------
Bug #5884: Float::NAN and 0.0/0.0 is represented differently when packed with 'g'
https://bugs.ruby-lang.org/issues/5884
Author: Hiro Asari
Status: Open
Priority: Normal
Assignee:
Category:
Target version:
ruby -v: ruby 2.0.0dev (2011-12-31 trunk 34165) [x86_64-darwin11.2.0]
$ ruby2.0 -e 'p [Float::NAN].pack("g")'
"\x7F\xC0\x00\x00"
$ ruby2.0 -e 'p [0.0/0.0].pack("g")'
"\xFF\xC0\x00\x00"
It would be nice to have Float::NAN and 0.0/0.0 behave identically in this regard.
--
http://bugs.ruby-lang.org/