benchmark a few styles of constructors in ruby

bench-init.rb

# I wanted to see how fast different constructor styles were.
#
# Calculating -------------------------------------
#                splat    73.970k i/100ms
#         manual splat    77.512k i/100ms
#                kwarg    23.687k i/100ms
#                 attr    77.930k i/100ms
#                 opts    34.173k i/100ms
#                fetch    29.289k i/100ms
# -------------------------------------------------
#                splat      1.912M (±21.2%) i/s -      8.950M
#         manual splat      1.671M (±19.0%) i/s -      7.984M
#                kwarg    268.841k (±41.2%) i/s -      1.066M
#                 attr      1.665M (±19.3%) i/s -      7.949M
#                 opts    439.918k (±48.4%) i/s -      1.674M
#                fetch    374.149k (±50.0%) i/s -      1.347M


require "benchmark/ips"

class A
  def initialize(a, b, c, d, e, f, g)
    @a = a
    @b = b
    @c = c
    @d = d
    @e = e
    @f = f
    @g = g
  end
end

class B
  def initialize(a:, b:, c:, d:, e:, f:, g:)
    @a = a
    @b = b
    @c = c
    @d = d
    @e = e
    @f = f
    @g = g
  end
end

class C
  attr_accessor :a, :b, :c, :d, :e, :f, :g
end

class D
  def initialize(opts)
    @a = opts[:a]
    @b = opts[:b]
    @c = opts[:c]
    @d = opts[:d]
    @e = opts[:e]
    @f = opts[:f]
    @g = opts[:g]
  end
end

class E
  def initialize(opts)
    @a = opts.fetch(:a)
    @b = opts.fetch(:b)
    @c = opts.fetch(:c)
    @d = opts.fetch(:d)
    @e = opts.fetch(:e)
    @f = opts.fetch(:f)
    @g = opts.fetch(:g)
  end
end

row = %w(a b c d e f g)
Benchmark.ips do |x|
  x.report("splat")        { |n| while n > 0; n -= 1; A.new(*row); end }
  x.report("manual splat") { |n| while n > 0; n -= 1; A.new(row[0], row[1], row[2], row[3], row[4], row[5], row[6]); end }
  x.report("kwarg")        { |n| while n > 0; n -= 1; B.new(a: row[0], b: row[1], c: row[2], d: row[3], e: row[4], f: row[5], g: row[6]); end }
  x.report("attr")         { |n| while n > 0; n -= 1; c = C.new; c.a = row[0]; c.b = row[1]; c.c = row[2]; c.d = row[3]; c.e = row[4]; c.f = row[5]; c.g = row[6]; end }
  x.report("opts")         { |n| while n > 0; n -= 1; D.new(a: row[0], b: row[1], c: row[2], d: row[3], e: row[4], f: row[5], g: row[6]); end }
  x.report("fetch")        { |n| while n > 0; n -= 1; E.new(a: row[0], b: row[1], c: row[2], d: row[3], e: row[4], f: row[5], g: row[6]); end }
end