From: rpmohn@... (Ross Mohn)
Date: 2000-12-03T12:40:05+09:00
Subject: [ruby-talk:6759] Re: Array Intersect (&) question

matju@cam.org (Mathieu Bouchard) wrote in 
<Pine.LNX.3.96.1001202135505.11964A-100000@relayer>:

>I think you can preserve order and use hashes.
>
>class Array
>     def &(other)
>          t = {}
>          r = []
>          other.each {|x| t[x]=1 }
>          uniq.each  {|x| r<<x if t.has_key? x }
>          r
>     end
>     def |(other)
>          t = {}
>          r = []
>          (self+other).each {|x| r<<x unless t.has_key?(x); t[x]=1 }
>          r
>     end
>     def uniq; self|[] end
>end

a1 = %w# a b c c c #
a2 = %w# b c #
a1 & a2 -> ["b", "c", "c", "c"]
a2 & a1 -> ["b", "c"]

I don't think that's okay:) -RPM
-- 
Ross Mohn
rpmohn@panix.com