def hash2locals(binding, hash)
  hash.each do |name, value|
    value = "ObjectSpace._id2ref(#{ value.object_id })"
    eval "#{ name } = #{ value }", binding
  end
  binding
end

def foo(locals)
  hash2locals lambda {}, locals
  bar
end

foo :bar => 12 #=> NameError: undefined local variable or method `bar' for main:Object