See https://github.com/graalvm/truffleruby/issues/375

bench_array_to_proc_iters.rb

require 'benchmark/ips'

class Array
  def to_proc
    if self[0].is_a? Symbol
      method, *arguments = self
      -> receiver { receiver.send method, *arguments  }
    elsif self[1].is_a? Symbol
      receiver, method, *arguments = self
      -> argument { receiver.send method, argument }
    else
      arguments = self
      -> receiver { receiver.to_proc[*arguments] }
    end
  end
end

array_of_numbers = 1..1_000_000
range = 20..40_000

Benchmark.ips do |x|
  x.iterations = 5
  
  x.report '#to_proc include?' do
    array_of_numbers.map &[range, :include?]
  end

  x.report 'block include?' do
    array_of_numbers.map { |number| range.include? number }
  end
  
  x.compare!
end


array_of_arrays = [[:a],[:b],[:c],[:d]]
array_to_append = [1,2]

Benchmark.ips do |x|
  x.iterations = 5
  
  x.report '#to_proc append' do
    array_of_arrays.map &[:+, array_to_append]
  end

  x.report 'block append' do
    array_of_arrays.map { |array| array + array_to_append  }
  end

  x.compare!
end

bench_array_to_proc_iters_const.rb

require 'benchmark/ips'

class Array
  def to_proc
    if self[0].is_a? Symbol
      method, *arguments = self
      -> receiver { receiver.send method, *arguments  }
    elsif self[1].is_a? Symbol
      receiver, method, *arguments = self
      -> argument { receiver.send method, argument }
    else
      arguments = self
      -> receiver { receiver.to_proc[*arguments] }
    end
  end
end

array_of_numbers = 1..1_000_000
MY_RANGE = 20..40_000

Benchmark.ips do |x|
  x.iterations = 5
  
  x.report '#to_proc include?' do
    array_of_numbers.map &[MY_RANGE, :include?]
  end

  x.report 'block include?' do
    array_of_numbers.map { |number| MY_RANGE.include? number }
  end
  
  x.compare!
end


array_of_arrays = [[:a],[:b],[:c],[:d]]
ARRAY_TO_APPEND = [1,2]

Benchmark.ips do |x|
  x.iterations = 5
  
  x.report '#to_proc append' do
    array_of_arrays.map &[:+, ARRAY_TO_APPEND]
  end

  x.report 'block append' do
    array_of_arrays.map { |array| array + ARRAY_TO_APPEND }
  end

  x.compare!
end