From: Tim Pease <tim.pease@...>
Date: 2006-12-20T06:03:46+09:00
Subject: Re: compare two objects without take its ID in consideration

On 12/19/06, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov> wrote:
>
> i prefer this pattern for the self documenting properties:
>
>    harp:~ > cat a.rb
>    class C
>      %w[ a b c ].each{|a| attr a}
>      def initialize a, b, c
>        @a, @b, @c = a, b, c
>      end
>      CMP_ATTRS = %w[ a b c ]
>      def == other
>        begin
>          x = CMP_ATTRS.map{|a| send a }
>          y = CMP_ATTRS.map{|a| other.send a }
>          x == y
>        rescue
>          false
>        end
>      end
>    end
>
>    p(  C.new(1,2,3) == C.new(1,2,3)  )
>    p(  C.new(1,2,3) == C.new(2,3,4)  )
>
>
>    harp:~ > ruby a.rb
>    true
>    false
>
>
> though it too suffers from cyclical structures...  sigh.
>

Infinite recursion only bothers me when I have a finite processor ;)

Yeah, you can shoot yourself in the foot no matter how careful you
are. I did like Joel's "ContentEquality" pattern elsewhere in this
thread. I'm going to have to adopt that one.

Blessings,
TwP