String building benchmark code

string_building_benchmark.rb

require 'benchmark'

TIMES = 100_000

strategies = [
  [ 'plusequals', proc { str = ""; TIMES.times { str += 'a' } } ],
  [ 'interp', proc { str = ""; TIMES.times { str = "#{str}a" } } ],
  [ 'concat', proc { str = ""; TIMES.times { str << "a" } } ],
  [ 'arrayjoin', proc { ary = []; TIMES.times { ary << 'a' }; str = ary.join } ] ]

10.times do
  Benchmark.bm do | bm |
    strategies.sort_by { rand }.each do | strategy |
      bm.report(strategy.first) { strategy.last.call }
    end
  end
end