Testing whether or not Enumerable#inject works well with a Hash.

each_or_inject.rb

require 'rubygems'
require 'ruby-prof'
require 'digest/md5'

$x = (1..100_000).to_a.map { |x| Digest::MD5.hexdigest(x.to_s) }

abort "Usage: #{__FILE__} (time|allocations) (inject|each)" if ARGV.length != 2

if ARGV[0] == 'time'
  RubyProf.measure_mode = RubyProf::PROCESS_TIME
elsif ARGV[0] == 'allocations'
  RubyProf.measure_mode = RubyProf::ALLOCATIONS
else
  abort "I don't know what to do!"
end

result = RubyProf.profile do
  if ARGV.last == 'inject'
    entries = $x.inject({}) do |h, q|
      h[q] = 'some string'
      h
    end
  elsif ARGV[1] == 'each'
    h = {}
    $x.each { |x| h[x] = 'some string' }
  else
    abort "I don't know what to do!"
  end
end

printer = RubyProf::GraphPrinter.new(result)
printer.print(STDOUT, 0)