From: "Michael W. Ryder" <_mwryder@...>
Date: 2008-05-27T07:24:28+09:00
Subject: Re: Why doesn't Float() work the same as Integer()?

Pit Capitain wrote:
> 2008/5/21 Michael W. Ryder <_mwryder@worldnet.att.net>:
>> The method allows Rational.new(3.5) and returns 7/2
> 
> I would be very careful with converting Floats to Rationals. You know
> that Rational.new(0.1) wouldn't return 1/10? If not you should read
> about IEEE 754, which is the basis for Ruby's floating point numbers.
> 

I realize that my implementation will not work with all allowable Floats 
such as Infinity, NAN, etc. but I am not trying to cover everything, 
just some of the most common.  I envision being able to use my version 
of the rational module to implement a command line calculator that could 
take "3.4 + 12 3/4" and return 16 3/20 or 16.15.
I can not see how you can say that 0.1 != 1/10.  I tried looking up the 
standard but the paper I looked at, about implementing the standard in a 
language, made no mention of converting floating point numbers to 
rational numbers.


> Regards,
> Pit
>