From: Yukihiro Matsumoto <matz@...>
Date: 2012-01-12T09:22:31+09:00
Subject: [ruby-core:42072] Re: [ruby-trunk - Bug #5884] Float::NAN and 0.0/0.0 is represented differently when packed with 'g'

Hi,

As far as I understand, the concept of "the NaN" itself is against the
definition of NaN in the IEEE 754 that defines NaN as set of floating
point values.  Correct me if I am wrong.

							matz.

In message "Re: [ruby-core:42069] [ruby-trunk - Bug #5884] Float::NAN and 0.0/0.0 is represented differently when packed with 'g'"
    on Thu, 12 Jan 2012 08:24:29 +0900, Hiro Asari <asari.ruby@gmail.com> writes:
|
|
|Issue #5884 has been updated by Hiro Asari.
|
|
|Besides it being status quo, what is the rationale behind not having Float::NAN and 0.0/0.0 act identically?
|
|As Brian mentioned, until the introduction of Float::NAN, 0.0/0.0 acted as a means of getting IEEE 754 NaN. If the intent for Float::NAN is to act as *the* NaN, then it seems reasonable to expect these objects to behave the same way in all manners possible.
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|Of course, if the purpose of Float::NAN is *not* to act as an identical object as 0.0/0.0, then this argument will not hold water.
|
|I don't have a personal stake in this manner; I just want a clarification. Thank you.
|----------------------------------------
|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/