From: Gary Wright <gwtmp01@...>
Date: 2009-04-15T02:39:14+09:00
Subject: Re: Argument types


On Apr 14, 2009, at 1:10 PM, Florian Kaufmann wrote:

>> An index is always a natural number. It is required to be either a  
>> Fixnum or
>> Bignum. You can't pass arbitrary object to those methods.
>
> It seems that it is more complex than that. This works
>
> %w(a b c)[1.2]

Because Float#.to_int is defined, although I'm not quite sure why.

This caused me to notice:

Float#ceil   to greater (or equal) integer
Float#floor  to smaller (or equal) integer

Float#to_int floor but towards towards zero (i.e. smaller abs value)
	-0.5.to_int == 0, 0.5.to_int == 0
	-0.6.to_int == 0, 0.6.to_int == 0

Float#round  rounds away from zero:
	-0.5.round == -1, 0.5.round == 1