Benchmark for approaches to SO [Split a string into parts in efficient way](http://stackoverflow.com/questions/15563251/split-a-string-into-parts-in-efficient-way/15563862)

split_into_word_pairs_bm.rb

#!/usr/bin/env ruby

require 'benchmark'

# 456976 four character words
STR = ('aaaa'..'zzzz').to_a * ' '
N = 10

puts RUBY_DESCRIPTION
puts "#{N} times on string of size #{STR.size}"

def original
  arr = STR.split(" ")
  set_element = arr.each_cons(2).to_a
  sub_str = set_element.map {|i| i.join(' ')}
end

def sergio
  arr = STR.split(" ")
  sub_str = arr.each_with_object([]).with_index do |(el, memo), idx|
    if idx % 2 == 0
      memo << el
    else
      memo.last << ' ' << el
    end
  end
end

def dbenhur
  STR.scan(/\S+(?:\s+\S+)?/)
end


Benchmark.bm(10) do |x|
  [:original, :sergio, :dbenhur].each do |method|
    x.report(method.to_s) { N.times { send(method) } }
  end
end