From: Phrogz <phrogz@...>
Date: 2007-11-07T13:50:02+09:00
Subject: Re: instance_eval to evaluate methods inside a block in context

On Nov 6, 6:46 pm, Adam Anderson <adamanderso...@gmail.com> wrote:
> http://pastie.caboo.se/114839
>
> Can anyone tell me why this wouldn't/shouldn't/should work? I don't
> want to pull out all of my hair trying to figure this out if it isn't
> even possible.

You can either do this:
class Calculator
  def evaluate(&script)
    self.instance_eval(&script)
  end
  def two
    "2"
  end
end

class Foo
  def hi
    puts "hi"
  end
  def howdy
    me = self
    Calculator.new.evaluate do
      puts two
      me.hi
    end
  end
end

Foo.new.howdy


...or this...

class Calculator
  def evaluate(&script)
    yield self
  end
  def two
    "2"
  end
end

class Foo
  def hi
    puts "hi"
  end
  def howdy
    Calculator.new.evaluate do |cal|
      puts cal.two
      hi
    end
  end
end

Foo.new.howdy