From: Gary Wright <gwtmp01@...>
Date: 2009-04-14T14:49:52+09:00
Subject: [ruby-core:23201] Re: [Bug #1336] Change in string representation of Floats


On Apr 14, 2009, at 1:05 AM, Yukihiro Matsumoto wrote:
> |Consider that (here at least):
> |2.1-3.0+0.9 ==  1.110223024625156540e-16
> |
> |I'd like to be proven wrong, but I currently believe that the one  
> cannot
> |create a human friendly Float string conversion that is also a  
> regenerating
> |representation.
>
> I agree with it.  My opinion is that IF we need to get regenerating
> string representation, we need a method dedicated to the purpose
> (e.g. dump).  I am not yet convinced we need such method.

I don't think it is even possible unless you introduce binary (or  
maybe hex) floating point literals.  That is the only way you are  
going to be able to safely round-trip between an internal IEEE  
floating point value and a string representation.

Gary Wright