respond_to_or_not_respond_to.rb

#! /usr/bin/env ruby

require 'benchmark'

N = 100_000

puts "Pessimistic:"
Benchmark.bm(50) do |bm|
  array = []
  1.upto(N) do
    array << Object.new
  end

  bm.report "respond_to?" do
    array.each do |object|
      if object.respond_to?(:xyzzy)
        raise "should not be here"
      end
    end
  end
  bm.report "NoMethodError" do
    array.each do |object|
      begin
        object.xyzzy()
        raise "should not be here"
      rescue NoMethodError
        # do nothing
      end
    end
  end
end

puts "Optimistic:"
Benchmark.bm(50) do |bm|
  array = []
  1.upto(N) do
    array << Object.new
  end

  bm.report "respond_to?" do
    array.each do |object|
      if object.respond_to?(:inspect)
        object.inspect
      else
        raise "should not be here"
      end
    end
  end
  bm.report "NoMethodError" do
    array.each do |object|
      begin
        object.inspect
      rescue NoMethodError
        raise "should not be here"
      end
    end
  end
end

results.txt

Pessimistic:
                                                        user     system      total        real
respond_to?                                         0.080000   0.030000   0.110000 (  0.116358)
NoMethodError                                       1.110000   0.090000   1.200000 (  1.216291)

Optimistic:
                                                        user     system      total        real
respond_to?                                         0.140000   0.050000   0.190000 (  0.198011)
NoMethodError                                       0.160000   0.050000   0.210000 (  0.211779)