From: Markus <markus@...>
Date: 2004-10-13T02:20:04+09:00
Subject: Re: "nan".to_f ?

> When would you *need* NaN in the first place? To show the the result of 
> some calculation is NaN? The just return that calculation.

     I don't have a specific example in mind.  Perhaps you're writing
something that evaluates a parameterized infinite series and want to
return NaN in the case where it doesn't converge (this being
significantly faster than an infinite loop).  Who knows?

     There may be other, better examples, but the point is _someone_ has
to be able to generate NaN, at some level (else we'd never see it) and
so it is at least plausible that that someone might be one of us.

> To test whether something is NaN? -> There's Float#nan? to do that.

     Good point.

-- Markus