From: Carlos <angus@...>
Date: 2006-08-10T02:48:38+09:00
Subject: Re: Enumerable#all? and empty arrays

Andre Nathan wrote:

> Hello
> 
> I found this to be somewhat amusing:
> 
> 
>>>a = []
> 
> => []
> 
>>>a.all?
> 
> => true
> 
>>>a.all? { |i| i == 10 }
> 
> => true
> 
> Is there any reasoning for Enumerable#all? to always return true for
> empty arrays?

It's what modern logic says... or something like it.

http://en.wikipedia.org/wiki/Square_of_opposition#The_problems_of_existential_import

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