Benchmark keyword arguments, normal arguments and an options hash in Ruby 2.1.5 and 2.2.3. Background: Koichi's talk on the evolution of keyword parameters at Ruby Conf PT - https://www.youtube.com/watch?v=qNaXZ1VWuvA. Inspired by https://gist.github.com/postmodern/5274138

benchmark_with_default_arguments.rb

require 'benchmark/ips'

def keyword(a:1,b:2,c:3)
  a + b + c
end

def normal(a=1,b=2,c=3)
  a + b + c
end

def options(params = {})
  a = params.fetch(:a, 1)
  b = params.fetch(:b, 2)
  c = params.fetch(:c, 3)
  a + b + c
end

Benchmark.ips do |bm|
  bm.report("keyword arguments") { keyword(a:7,b:8,c:9) }
  bm.report("normal arguments") { normal(7,8,9) }
  bm.report("options hash") { options(a: 7,b: 8,c: 9) }
  bm.compare!
end

# Ruby 2.1.5
# Calculating -------------------------------------
#    keyword arguments    22.074k i/100ms
#     normal arguments    70.955k i/100ms
#         options hash    31.267k i/100ms
# -------------------------------------------------
#    keyword arguments    319.329k (± 3.6%) i/s -      1.611M
#     normal arguments      3.340M (± 4.4%) i/s -     16.674M
#         options hash    545.974k (± 4.1%) i/s -      2.751M

# Comparison:
#     normal arguments:  3339916.0 i/s
#         options hash:   545974.2 i/s - 6.12x slower
#    keyword arguments:   319329.1 i/s - 10.46x slower

# Ruby 2.2.3
# Calculating -------------------------------------
#    keyword arguments    66.866k i/100ms
#     normal arguments    69.380k i/100ms
#         options hash    32.776k i/100ms
# -------------------------------------------------
#    keyword arguments      2.742M (± 3.6%) i/s -     13.708M
#     normal arguments      3.316M (± 4.1%) i/s -     16.582M
#         options hash    570.139k (± 3.6%) i/s -      2.852M

# Comparison:
#     normal arguments:  3315957.5 i/s
#    keyword arguments:  2741896.6 i/s - 1.21x slower
#         options hash:   570139.0 i/s - 5.82x slower

# This example supplies no arguments so that the default values are used
Benchmark.ips do |bm|
  bm.report("keyword arguments") { keyword }
  bm.report("normal arguments") { normal }
  bm.report("options hash") { options }
  bm.compare!
end


# Ruby 2.1.5
# Calculating -------------------------------------
#    keyword arguments    59.167k i/100ms
#     normal arguments    70.488k i/100ms
#         options hash    54.960k i/100ms
# -------------------------------------------------
#    keyword arguments      2.031M (± 3.6%) i/s -     10.177M
#     normal arguments      3.355M (± 3.5%) i/s -     16.776M
#         options hash      1.489M (± 3.1%) i/s -      7.475M

# Comparison:
#     normal arguments:  3354831.4 i/s
#    keyword arguments:  2030610.2 i/s - 1.65x slower
#         options hash:  1489103.3 i/s - 2.25x slower

# Ruby 2.2.3
# Calculating -------------------------------------
#    keyword arguments    70.215k i/100ms
#     normal arguments    70.195k i/100ms
#         options hash    56.138k i/100ms
# -------------------------------------------------
#    keyword arguments      3.032M (± 3.6%) i/s -     15.166M
#     normal arguments      3.195M (± 4.1%) i/s -     16.004M
#         options hash      1.704M (± 7.6%) i/s -      8.421M

# Comparison:
#     normal arguments:  3195331.5 i/s
#    keyword arguments:  3031580.0 i/s - 1.05x slower
#         options hash:  1704400.8 i/s - 1.87x slower

benchmark_without_default_arguments.rb

require 'benchmark/ips'

def keyword(a:,b:,c:)
  a + b + c
end

def normal(a,b,c)
  a + b + c
end

def options(params)
  a = params.fetch(:a)
  b = params.fetch(:b)
  c = params.fetch(:c)
  a + b + c
end

Benchmark.ips do |bm|
  bm.report("keyword arguments") { keyword(a:7,b:8,c:9) }
  bm.report("normal arguments") { normal(7,8,9) }
  bm.report("options hash") { options(a: 7,b: 8,c: 9) }
  bm.compare!
end


# Ruby 2.1.5
# Calculating -------------------------------------
#    keyword arguments    21.624k i/100ms
#     normal arguments    73.576k i/100ms
#         options hash    32.015k i/100ms
# -------------------------------------------------
#    keyword arguments    318.974k (± 3.7%) i/s -      1.600M
#     normal arguments      3.541M (± 3.4%) i/s -     17.732M
#         options hash    557.704k (± 3.1%) i/s -      2.817M

# Comparison:
#     normal arguments:  3541085.7 i/s
#         options hash:   557704.3 i/s - 6.35x slower
#    keyword arguments:   318974.2 i/s - 11.10x slower

# Ruby 2.2.3
# Calculating -------------------------------------
#    keyword arguments    65.847k i/100ms
#     normal arguments    69.809k i/100ms
#         options hash    33.905k i/100ms
# -------------------------------------------------
#    keyword arguments      2.856M (± 4.1%) i/s -     14.289M
#     normal arguments      3.839M (± 4.5%) i/s -     19.197M
#         options hash    566.961k (± 4.5%) i/s -      2.848M

# Comparison:
#     normal arguments:  3839040.8 i/s
#    keyword arguments:  2855939.8 i/s - 1.34x slower
#         options hash:   566961.1 i/s - 6.77x slower

👍

@pedrocarrico I swapped standard lib's benchmark for benchmark-ips. Everything reads more clearly now!