From: gotoken@... (GOTO Kentaro)
Date: 2001-03-06T19:54:22+09:00
Subject: [ruby-talk:12115] Re: NaN, Infinity (Bug?)

In message "[ruby-talk:12112] NaN, Infinity (Bug?)"
    on 01/03/06, Tammo Freese <tammo.freese@offis.de> writes:
>After the Pickaxe Book, first print, p. 320
>a = -1.0        -> -1.0
>a.nan?          -> false
>a = Math.log(a) -> NaN
>a.nan?          -> true
>
>But testing (ruby 1.6.2 (2000-12-18) [i386-cygwin])

>-1.0
>false
>-Infinity
>false

I've got:

  $ ruby -ve 'p [(x = Math::log(-1.0)), x.nan?]'
  ruby 1.6.2 (2000-12-13) [i386-freebsdelf4.1]
  [NaN, true]

>Is this a defect or an error in the pickaxe book?

The problem is in interpreter-binary or dll, IMHO. 

-- Gotoken