I18N east slavic pluralization benchmark

bm.rb

require "benchmark/ips"
require "set"

OLD_CODE = ->(n){
  mod10 = n % 10
  mod100 = n % 100

  if mod10 == 1 && mod100 != 11
    :one
  elsif [2, 3, 4].include?(mod10) && ![12, 13, 14].include?(mod100)
    :few
  elsif mod10 == 0 || (5..9).to_a.include?(mod10) || (11..14).to_a.include?(mod100)
    :many
  else
    :other
  end
}

FROM_2_TO_4   = (2..4).to_set
FROM_5_TO_9   = (5..9).to_set
FROM_11_TO_14 = (11..14).to_set
FROM_12_TO_14 = (12..14).to_set

NEW_CODE = ->(n){
  mod10 = n % 10
  mod100 = n % 100

  if mod10 == 1 && mod100 != 11
    :one
  elsif FROM_2_TO_4.include?(mod10) && !FROM_12_TO_14.include?(mod100)
    :few
  elsif mod10 == 0 || FROM_5_TO_9.include?(mod10) || FROM_11_TO_14.include?(mod100)
    :many
  else
    :other
  end
}

SAMPLE = 1000.times.map{ rand(0...999) } + 100.times.map{ rand(0...999).to_f / 10 }

Benchmark.ips do |x|
  x.report("old code"){ SAMPLE.each{ |n| OLD_CODE[n] }}
  x.report("new code"){ SAMPLE.each{ |n| NEW_CODE[n] }}
end