From: "I. E. Smith-Heisters" <i@0x09.com>
Date: 2008-09-17T04:17:41+09:00
Subject: define anonymous module with closure

Hi everyone,

I want to do this:

  x, y = %w(x y)
  definition = lambda{def z; x; end}
  y.extend Module.new(&definition)
  y.z # => 'x'

I expected x to be available within the closure, but it doesn't appear
to be. The only way I've found is with module_eval:

  x, y = %w(x y)
  mod = Module.new
  mod.module_eval "def z; #{x.inspect}; end"
  y.extend mod
  y.z # => 'x'

Which I guess is fine, but I'm opposed to eval, and especially
eval'ing strings, on principle.

So:

Why doesn't the first option work? I saw something somewhere about the
argument to Module::new being called within some other scope/context/
whatsit?

Is there a way to do this without eval?

Thanks!
-Ian