From: Marc-Andre Lafortune <ruby-core-mailing-list@...>
Date: 2010-04-21T00:04:49+09:00
Subject: [ruby-core:29663] Re: [Feature #1408] 0.1.to_r not equal to (1/10)

Hi,

On Tue, Apr 20, 2010 at 7:03 AM, tadayoshi funaba <redmine@ruby-lang.org> wrote:
> a.rationalize == a #=> false

Clearly, a_float.rationalize.to_f.should == a_float

If it doesn't round trip, it is a problem and should be addressed.


It does round trip, at least on my system:

$ rubydev -v
ruby 1.9.2dev (2010-04-07 trunk 27251) [x86_64-darwin10.3.0]
or ruby 1.9.2dev (2010-04-20 trunk 27420) [x86_64-darwin10.3.0]
$ irbdev
a = 0.5337486539516013
b = 0.5337486539516012
a.rationalize == a
# => true
b.rationalize == b
# => true
100_000.times.all?{ f = rand; f.rationalize == f}
# => true
What version of Ruby are you using, and on what system?

BTW, a.rationalize == (7742439284/14505777629) and b.rationalize ==
(6224985158/11662765071).  (at least on my machine!)