gistfile1.txt

class Foo
  def initialize
    @x=10
  end
end

f = Foo.new
i = 1
b = f.instance_eval do
  # this binding can see all members of f (like @x) as well as variables in the outer sopce (like i)
  binding
end

puts eval("@x",b)
puts eval("f",b)
puts eval("i",b)