From: Markus <markus@...>
Date: 2004-10-15T03:05:16+09:00
Subject: Re: "nan".to_f ?


     My mistake is clear.  I was assuming Float == IEEE.

     I still see the original poster's desire to be able to serialize
floats as text without gross changes, but do not at this point see a
clear and portable way of implementing it.  At best (using the code I
posted yesterday morning) you could maintain the distinction between
error-values and numbers, but this might well silently morph (say) Inf
to NaN, etc.

        -- Markus



On Thu, 2004-10-14 at 09:44, GOTO Kentaro wrote:
> Hi, 
> 
> In message "Re: "nan".to_f ?"
>     on Thu, 14 Oct 2004 02:39:43 +0900, Yukihiro Matsumoto wrote:
> > |  def aNaN
> > |    s, e, m = rand(2), 2047, rand(2**52-1)+1
> > |    [sprintf("%1b%011b%052b", s,e,m)].pack("B*").unpack("G").first
> > |  end
> > |
> > |I believe this will generate NaN on environments where 
> > |pack/unpack works and NaN exists. 
> > 
> > If the platform uses IEEE floating number, right?
> 
> Agreed!  And if there exists NaN on a non IEEE platform, 
> that NaN must be another concept because NaN is defined in 
> IEEE 754.  
> 
> 
> Gotoken