etanni.rb

class Etanni
  SEPARATOR = "E69t116A65n110N78i105S83e101P80a97R82a97T84o111R82"
  CHOMP = "<<#{SEPARATOR}.chomp!"
  START = "\n_out_ << #{CHOMP}\n"
  STOP = "\n#{SEPARATOR}\n"
  REPLACEMENT = "#{STOP}\\1#{START}"

  def initialize(template, filename = '<Etanni>')
    @template = template
    @filename = filename
    compile
  end

  def compile(filename = @filename)
    temp = @template.strip
    temp.gsub!(/<\?r\s+(.*?)\s+\?>/m, REPLACEMENT)
    @compiled = eval("Proc.new{ _out_ = [#{CHOMP}]\n#{temp}#{STOP}_out_.join }",
      nil, @filename)
  end

  def result(instance, filename = @filename)
    instance.instance_eval(&@compiled)
  end
end

ENV['R_HOME'] ||= '/usr/lib/R'
require 'better-benchmark'

class BetterBenchmark
  attr_reader :reports

  def self.bmbm(*args, &block)
    new.bmbm(*args, &block)
  end

  def initialize
    @reports = []
  end

  def bmbm(*args)
    yield self

    reports.combination(2) do |left, right|
      left_title, left_block, right_title, right_block = *left, *right
      result = Benchmark.compare_realtime(*args, &left_block).with(&right_block)

      puts "\n\n#{left_title} vs #{right_title}"
      Benchmark.report_on result
    end
  end

  def report(title, &block)
    reports << [title, block]
  end
end

etanni = Etanni.new('Hello, #{name}')
d = Struct.new(:name).new('manveru')

BetterBenchmark.bmbm do |bench|
  bench.report 'fast' do
    etanni.result(d)
  end

  bench.report 'medium' do
    etanni = Etanni.new('Hello, #{name}')
    etanni.result(d)
  end

  bench.report 'slow' do
    etanni = Etanni.new('Hello, #{name}')
    d = Struct.new(:name).new('manveru')
    etanni.result(d)
  end
end