Ruby dynamic features

eval
class_eval
module_eval

const_get

instance_variable_get
instance_variable_set

define_method

const_missing

undef
remove_method
undef_method
remove_const

ancestors
constants
class_variables
instance_variables
instance_methods
public_instance_methods
protected_instance_methods
included_modules
private_methods
public_methods

caller

set_trace_func

ObjectSpace.each_object

method_missing

alias_method

singleton_method_added
inherited
included

extend_object

define_finalizer

block_given?
yield