ruby 1.9 eval and AST creates varibales when encountered

ruby_eval.rb

#dkannan: 	raggi: just copy-pasted the whole thing	1:04 PM
#raggi: 	the defined?(o = something) is basically a bug i think	1:05 PM
#raggi; 	not 100% on that, but i think it's an AST bug, you can do a similar thing in other ways	1:06 PM
#raggi: 	(that is, you can make local variables come into existence without assigning to them)

# short-circuit
puts defined? foo
false && (foo = "will this be assigned")
puts defined? foo
puts foo.inspect

# asssignment - raggi's code
b = :b if b
local_varaibles # => ['b']

# in 1.9 eval does not modify the enclosing scope, have to pass it an explicit binding
def test bool
  eval('a = 1; puts a;') if bool
  # what about functions
  puts "a in env: #{a}" rescue nil
  return local_variables, defined?(a), eval('defined?(a)')
end

p test(true)
p test(false)