require "benchmark"

def mangle_one(name)
  name.gsub do |char|
    if char == 'o'
      ".#{char.ord.to_s(16)}."
    else
      char
    end
  end
end

def mangle_two(name)
  String.build do |io|
    name.each_char do |char|
      if char == 'o'
        io << '.'
        char.ord.to_s(16, io)
        io << '.'
      else
        io << char
      end
    end
  end
end

def mangle_three(name)
  name.gsub('x', 'y')
end

Benchmark.ips do |x|
  x.report("one") do
    mangle_one("foo bar")
  end
  x.report("two") do
    mangle_two("foo bar")
  end
  x.report("three") do
    mangle_three("foo bar")
  end
end