How do you stringize/serialize Ruby code?

Question

I want to be able to write a lambda/Proc in my Ruby code, serialize it so that I can write it to disk, and then execute the lambda later. Sort of like...

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Answer 1

Use sourcify

This will work on Ruby 1.8 or 1.9.

def save_for_later(&block)
  block.to_source
end

x = 40
s = save_for_later {|y| x + y }
# => "proc { |y| (x + y) }"
g = eval(s)
# => #
g.call(2) 
# => 42

See my other answer for capturing free variables.

Update: Now you can also use the serializable_proc gem, which uses sourcify, and captures local, instance, class, and global variables.