From: Erik Veenstra <erikveen@...>
Date: 2007-01-30T06:19:26+09:00
Subject: Re: "a string".xor("another string")

I've found a little bug in your version:

 long   = "this is a very long string"
 short  = "a short one"

 p long.xor(short)   # ==> OK
 p short.xor(long)   # ==> Array size mismatch: 11 != 26

See this fix.

gegroet,
Erik V. - http://www.erikveen.dds.nl/

----------------------------------------------------------------

 require "narray"

 class String
   def xor(other)
     if other.empty?
       self
     else
       s1        = self
       s2        = other

       if s1.length < s2.length
         n, r    = s2.length.divmod(s1.length)
         s1      = s1 * n + s1[0, r]
       elsif s2.length < s1.length
         n, r    = s1.length.divmod(s2.length)
         s2      = s2 * n + s2[0, r]
       end

       a1        = NArray.to_na(s1, "byte")
       a2        = NArray.to_na(s2, "byte")

       (a1 ^ a2).to_s
     end
   end
 end

----------------------------------------------------------------