basic_object_test.rb

# -*- encoding: utf-8 -*-

class BlankSlate < BasicObject
  def method_missing(name, *args)
    "BlankSlate##{name} called"
  end

  def respond_to?(name)
    name.to_s == 'hoge'
  end
end

class A
  def hoge
    'moge'
  end
end

def main
  begin
    BasicObject.new.respond_to?(:==) # =>
  rescue => x
    x # => #<NoMethodError: undefined method `respond_to?' for #<BasicObject:0x007ff4ab80f5a0>>
  end

  bs = BlankSlate.new
  bs.respond_to?(:hoge) # => true
  bs.respond_to?(:moge) # => false
  bs.respond_to?(:__send__) # => false
  bs.hoge # => "BlankSlate#hoge called"
  bs.__send__(:hoge) # => "BlankSlate#hoge called"

  Object.ancestors # => [Object, Kernel, BasicObject]
  BasicObject.instance_methods # => [:==, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__, :__id__]
  Kernel.instance_methods - BasicObject.instance_methods # => [:nil?, :===, :=~, :!~, :eql?, :hash, :<=>, :class, :singleton_class, :clone, :dup, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :freeze, :frozen?, :to_s, :inspect, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variables, :instance_variable_get, :instance_variable_set, :instance_variable_defined?, :remove_instance_variable, :instance_of?, :kind_of?, :is_a?, :tap, :send, :public_send, :respond_to?, :extend, :display, :method, :public_method, :singleton_method, :define_singleton_method, :object_id, :to_enum, :enum_for]
  Object.instance_methods - Kernel.instance_methods # => [:==, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__, :__id__]

  Object.new.method(:instance_variable_set).methods - Object.instance_methods # => [:call, :[], :arity, :to_proc, :receiver, :name, :original_name, :owner, :unbind, :source_location, :parameters]
  Object.new.method(:instance_variable_set).source_location # => nil
  Object.new.method(:instance_variable_set).parameters # => [[:req], [:req]]
  Object.new.method(:instance_variable_set).arity # => 2
  Object.new.method(:instance_variable_set).receiver # => #<Object:0x007ff4ab80c3c8>
  Object.new.method(:instance_variable_set).original_name # => :instance_variable_set
  Object.new.method(:instance_variable_set).name # => :instance_variable_set
  Object.new.method(:instance_variable_set).owner # => Kernel
  Object.new.method(:instance_variable_set).source_location # => nil
  Object.new.method(:instance_eval).source_location # => nil
  Object.new.method(:__id__).source_location # => nil
  A.new.method(:hoge).source_location # => ["/Users/kameda/work/basic_object_test.rb.rubyeval", 14]
end

case $PROGRAM_NAME
when __FILE__
  main
when /spec[^\/]*$/
  # {spec of the implementation}
end