ruby2.0更改绑定和eval-ruby2.0changesforbindingandeval

While migrating code from ruby 1.8.6 to 2.0 I noticed that the behaviour of eval with bindings has changed. I did not find any information about that and the documentation of those methods has not changed its wording.

在将代码从ruby 1.8.6迁移到2.0时，我注意到带有绑定的eval的行为已经改变。我没有找到任何有关这方面的信息，这些方法的文档没有改变其措辞。

object = Math
binding = object.__send__(:binding)
puts eval("self", binding)
puts eval("sin(0.2)", binding)

gives in irb1.8:

在irb1.8中给出：

> Math
> 0.1986…

and in irb2.0:

并在irb2.0中：

> main
> NoMethodError

I get the same when using the new binding.eval("self")

使用新的binding.eval（“self”）时我也一样

What is the underlying change, and how can I implement the previous behavior in Ruby 2.0?

什么是潜在的变化，我如何在Ruby 2.0中实现以前的行为？

1 个解决方案

 b = Math.__send__(:binding)
 b.eval("self")
 => main

 b = Math.instance_eval { binding }
 b.eval("self")
 => Math

 # or equivalently...
 b = Math.instance_eval("binding")
 b.eval("self")
 => Math