Rubinius String#scan benchmark

bench_scan.rb

  require 'benchmark'
  require 'benchmark/ips'

  long_text = File.new('holmes.txt').read.downcase
    #holmes.txt @  http://norvig.com/holmes.txt
  medium_text = long_text.slice(0,1000)
  short_text = long_text.slice(0,100)

  Benchmark.ips do |x|
    x.report "string scan (long length)" do |times|
      i = 0
      while i < times
         a = long_text.scan(/[a-z]+/)
         i += 1
      end
    end
    x.report "string scan (medium length)" do |times|
      i = 0
      while i < times
         a = medium_text.scan(/[a-z]+/)
         i += 1
      end
    end
    x.report "string scan (short length)" do |times|
      i = 0
      while i < times
         a = short_text.scan(/[a-z]+/)
         i += 1
      end
    end
  end

That's a good start. I'd send that as a pull request. We can always improve it later. The "holmes.txt" would need to be committed to the repository too.