From: Robert Dober <robert.dober@...>
Date: 2007-06-07T05:30:43+09:00
Subject: Re: === operator

On 6/6/07, Jon Leighton <turnip@turnipspatch.com> wrote:
> Hi,

Maybe a more explicit notation helps
>
> >> {} === Hash
{}.send(:===, Hash)
> => false
> >> case {}
> >> when Hash then true
when Hash.send(:===, {}) then true
> >> end
> => true
> >> Hash === {}
> => true
>
> Why is the first statement false when the second is true? I understand
> case uses === to compare the objects? Perhaps it switches them round as
> in the last statement?
No the LHS is the receiver and the RHS is the first argument of the message.
{}.send(:===, Hash) the === instance_method of Hash is called which is
inherited from Object and basically means equality, hence false.

Hash.send(:===, {}) the class method of Hash is called which is
inherited from Class and means is_a? hence true.

HTH
Robert


-- 
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw