switchの書き方ごとにベンチマーク取ってみた結果

switch_test.rb

# -*- encoding: utf-8 -*-
require 'benchmark'

class Character < Struct.new(:name, :level, :point)
  def to_s
    "%s:\tlv:%d\tpt:%d" % values
  end
end


def bonus_point0(chara)
  if chara.level.between?(1, 3)
    chara.point += 10
  elsif chara.level.between?(4, 7)
    chara.point += 5
  elsif chara.level.between?(8, 9)
    chara.point += 3
  else
  end
end

def bonus_point1(chara)
  case
  when chara.level.between?(1, 3)
    chara.point += 10
  when chara.level.between?(4, 7)
    chara.point += 5
  when chara.level.between?(8, 9)
    chara.point += 3
  else
  end
end

def bonus_point2(chara)
  case chara.level
  when 1, 2, 3
    chara.point += 10
  when 4, 5, 6, 7
    chara.point += 5
  when 8, 9
    chara.point += 3
  else
  end
end

def bonus_point3(chara)
  case chara.level
  when 1..3
    chara.point += 10
  when 4..7
    chara.point += 5
  when 8, 9
    chara.point += 3
  else
  end
end

def bonus_point4(chara)
  low, mid, high = [1,2,3], [4,5,6,7], [8,9]
  case chara.level
  when *low
    chara.point += 10
  when *mid
    chara.point += 5
  when *high
    chara.point += 3
  else
  end
end

def bonus_point5(chara)
  low, mid, high = [1,2,3], [4,5,6,7], [8,9]
  chara.point +=
    case chara.level
    when *low
      10
    when *mid
      5
    when *high
      3
    else
      0
    end
end

def bonus_point6(chara)
  low, mid, high = [1,2,3], [4,5,6,7], [8,9]
  chara.point +=
    case chara.level
    when *low  then 10
    when *mid  then 5
    when *high then 3
    else            0
    end
end

def bonus_point7(chara)
  low, mid, high = [1,2,3], [4,5,6,7], [8,9]
  chara.point +=
    case chara.level
    when *low  ; 10
    when *mid  ; 5
    when *high ; 3
    else         0
    end
end

def bonus_point8(chara)
  low, mid, high = [1,2,3], [4,5,6,7], [8,9]

  chara.point += begin
    case chara.level
    when *low  ; 10
    when *mid  ; 5
    when *high ; 3
    else         0
    end
  end
end


def bonus_point9(chara)
  is_low  = ->lv{(1..3).include? lv}
  is_mid  = ->lv{(4..7).include? lv}
  is_high = ->lv{(8..9).include? lv}
  chara.point +=
    case chara.level
    when is_low  ; 10
    when is_mid  ; 5
    when is_high ; 3
    else           0
    end
end

def bonus_point10(chara)
  chara.point +=
    case chara.level
    when low10?  ; 10
    when mid10?  ; 5
    when high10? ; 3
    else           0
    end
end

def low10?
  -> lv {(1..3).include? lv}
end

def mid10?
  -> lv {(4..7).include? lv}
end

def high10?
  -> lv {(8..9).include? lv}
end

def bonus_point11(chara)
  chara.point +=
    case chara.level
    when low11?  ; 10
    when mid11?  ; 5
    when high11? ; 3
    else           0
    end
end

def level_seed(range)
  -> lv {range.include? lv}
end

def low11?
  level_seed(1..3)
end

def mid11?
  level_seed(4..7)
end

def high11?
  level_seed(8..9)
end


#charlie = Character.new('Charlie', 5, 0)
#liz = Character.new('Liz', 3, 0)
#ben = Character.new('Ben', 8, 0)
#
#charas = [charlie, liz, ben]
#charas.each {|c| bonus_point c}
#puts charas
#
#expected_result = <<-EOS
#Charlie:	lv:5	pt:5
#Liz:	lv:3	pt:10
#Ben:	lv:8	pt:3
#EOS
#
#charas.map(&:to_s).join("\n") == expected_result.chomp

def prepare_charas
  charlie = Character.new('Charlie', 5, 0)
  liz     = Character.new('Liz', 3, 0)
  ben     = Character.new('Ben', 8, 0)
  [charlie, liz, ben]
end

puts "RUBY_VERSION: #{RUBY_VERSION}"

n = 10000
Benchmark.bm(8) do |x|
  x.report("bonus_point0:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point0 c} }
  }
  x.report("bonus_point1:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point1 c} }
  }
  x.report("bonus_point2:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point2 c} }
  }
  x.report("bonus_point3:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point3 c} }
  }
  x.report("bonus_point4:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point4 c} }
  }
  x.report("bonus_point5:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point5 c} }
  }
  x.report("bonus_point6:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point6 c} }
  }
  x.report("bonus_point7:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point7 c} }
  }
  x.report("bonus_point8:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point7 c} }
  }
  x.report("bonus_point9:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point9 c} }
  }
  x.report("bonus_point10:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point10 c} }
  }
  x.report("bonus_point11:")  {
    charas = prepare_charas
    n.times { charas.each {|c| bonus_point11 c} }
  }
end

# >> RUBY_VERSION: 2.1.1
# >>                user     system      total        real
# >> bonus_point0:  0.030000   0.000000   0.030000 (  0.034863)
# >> bonus_point1:  0.030000   0.000000   0.030000 (  0.024595)
# >> bonus_point2:  0.010000   0.000000   0.010000 (  0.013378)
# >> bonus_point3:  0.030000   0.000000   0.030000 (  0.025469)
# >> bonus_point4:  0.040000   0.000000   0.040000 (  0.043132)
# >> bonus_point5:  0.040000   0.000000   0.040000 (  0.043047)
# >> bonus_point6:  0.050000   0.000000   0.050000 (  0.049851)
# >> bonus_point7:  0.050000   0.000000   0.050000 (  0.043896)
# >> bonus_point8:  0.040000   0.000000   0.040000 (  0.041393)
# >> bonus_point9:  0.080000   0.000000   0.080000 (  0.080405)
# >> bonus_point10:  0.080000   0.000000   0.080000 (  0.087997)
# >> bonus_point11:  0.100000   0.000000   0.100000 (  0.093977)