From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-06-10T06:25:57+09:00
Subject: Re: python/ruby benchmark.

On Fri, 10 Jun 2005, Gyoung-Yoon Noh wrote:

> Using 'set' is somewhat faster than Hash in 1.9.
> I've rewritten that code using 'set' as following:
>
>  require 'set'
>
>  d = Set.new
>
>  File.open('/usr/share/dict/words') do |f|
>    d << $_.chop! while f.gets
>  end
>
>  STDIN.each do |l|
>    puts l unless d.include? l.chop!
>  end
>
> Here are timed results in my machine.

hmmm.  since set uses hash yet has at least another level of method calls
that's hard to believe... this is what i'm getting:

   harp:~ > ruby a.rb
   ========< set >========
   3.818156

   ========< hash >========
   2.572087


   harp:~ > ruby a.rb
   ========< set >========
   3.824544

   ========< hash >========
   2.600603


   harp:~ > cat a.rb
   require 'set'

   def bench label
     fork {
       GC.disable
       STDOUT.sync = true
       puts "========< #{ label } >========"
       a = Time::now.to_f
       yield
       b = Time::now.to_f
       printf "%f\n", b - a
       puts
     }
     Process::wait
   end

   words = IO::readlines('/usr/share/dict/words').map{|word| word.strip}

   set = Set::new
   hash = Hash::new

   words.each{|word| set << hash[word] = word}

   bench('set'){ 42.times{ words.each{|word| set.include? word}}}
   bench('hash'){ 42.times{ words.each{|word| hash.has_key? word}}}


note that times are the time it takes to look up every single word in the list
42 times.

cheers.

-a
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