From: Robert Klemme <shortcutter@...>
Date: 2011-12-30T08:26:31+09:00
Subject: Re: What’s the standard way of implementing #hash for value objects in Ruby?

On Thu, Dec 29, 2011 at 4:06 PM, Nikolai Weibull <now@bitwi.se> wrote:
> On Thu, Dec 29, 2011 at 15:52, Gunther Diemant <g.diemant@gmx.net> wrote:
>> I think you can't access instance variables from a class method, so
>> both methods are kinda useless.
>
> Ugh, that should of course be
>
> class A
>  def hash
>     …
>  end
> end

Easy way:

class A
  def hash
    [@a, @b, @c].hash
  end
end

Easiest:

# also gives you == and eql?
A = Struct.new :a, :b, :c

Kind regards

robert

-- 
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