From: GOTO Kentaro <gotoken@...>
Date: 2004-10-16T03:39:51+09:00
Subject: Re: "nan".to_f ?

In message Re: "nan".to_f ?
 on Fri, 15 Oct 2004 03:05:16 +0900, Markus:

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

Mistake? I don't think you mistook. or I also mistake. 
When we are talking about Ruby, NaN means IEEE 754's NaN, isn't it?  :)

>      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.

NaN was designed to represent abnormal result of an arithmetic operation. 
So, IMHO, String#to_f is not arithmetic and should not returns NaN. 
By the way, we sometimes want to define a method return NaN value. 
In such situations I believe pack/unpack will help. 


Gotoken