From: Kent Dahl <kentda@...>
Date: 2003-01-18T08:28:48+09:00
Subject: Re: Accessing Infinity

Joel VanderWerf wrote:
> 
> But...
> 
> (1.2).equal?(1.2)           # ==> false
> (10**100).equal?(10**100)   # ==> false
> 
> Does that mean there are an infinity of googols?

Maybe, I'm no math buff, but I was thinking more about the fact that
they are heap allocated entities. When I read "two infinities" before
"reasonable to compare with them", I thought you might be under the
illusion that the infinity objects are shared single instances or
immediate values. My bad, and good to see you aren't. 

> I don't think #equal? is the mathematically correct comparison for
> numbers that may be implemented as heap allocated entities. That's the
> job of #==.

And checking for infinity isn't the job of neither of those, but
Float#infinite? since it is such a special value. Using #== is a bad
idea for Floats in general due to imprecision, and chucking them up for
infinity goes against code clarity, IMHO. 

-- 
(\[ Kent Dahl ]/)_    _~_    __[ http://www.stud.ntnu.no/~kentda/ ]___/~
 ))\_student_/((  \__d L b__/  NTNU - graduate engineering - 5. year  )
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