#!/usr/bin/env ruby


class Flaw_demo
   def initialize
   end # initialize

   def show_that_the_Binding_instances_are_readable
      bn_x=binding()
      s_x="\nReading from Binding instances works.\n"
      eval("puts s_x",bn_x)
   end # show_that_the_Binding_instances_are_readable


   def show_that_overwriting_of_existing_vars_works_fine
      bn_x=binding()
      s_x="\nText subject to overwriting."
      eval("s_x=\"\\nThe modification of an existing variable succeeded.\"",bn_x)
      puts s_x
   end # show_that_overwriting_of_existing_vars_works_fine

   def the_flaw_is_that_new_variables_can_not_be_created_to_Binding_instances
      bn_x=binding()
      eval("s_x=\"\\nA value of a newly created variable\"",bn_x)
      puts s_x
   end # the_flaw_is_that_new_variables_can_not_be_created_to_Binding_instances


   def run_demo
      show_that_the_Binding_instances_are_readable()
      show_that_overwriting_of_existing_vars_works_fine()
      the_flaw_is_that_new_variables_can_not_be_created_to_Binding_instances()
   end # run_demo

end # class Flaw_demo

Flaw_demo.new.run_demo()

=begin

# The console output:

ts2@taustas8lm2:~/tmp$ ./flaw_demo.rb 

Reading from Binding instances works.

The modification of an existing variable succeeded.
./flaw_demo.rb:25:in `the_flaw_is_that_new_variables_can_not_be_created_to_Binding_instances': undefined local variable or method `s_x' for #<Flaw_demo:0x000000014a2620> (NameError)
	from ./flaw_demo.rb:32:in `run_demo'
	from ./flaw_demo.rb:37:in `<main>'
ts2@taustas8lm2:~/tmp$ ruby -v
ruby 2.0.0p195 (2013-05-14) [x86_64-linux]
ts2@taustas8lm2:~/tmp$ date
Thu May 23 09:22:53 EEST 2013
ts2@taustas8lm2:~/tmp$

=end