我有以下课程：
class User
code1 = Proc.new { }
code2 = lambda { }
define_method :test do
self.class.instance_eval &code1
self.class.instance_eval &code2
end
end
User.new.test
解决方法
instance_eval正在向lambda产生self(User). Lambdas特别关注它们的参数 – 与方法相同 – 并且如果太少/很多则会引发ArgumentError.
class User
code1 = Proc.new { |x| x == User } # true
code2 = lambda { |x| x == User } # true
define_method :test do
self.class.instance_eval &code1
self.class.instance_eval &code2
end
end
相关：What’s the difference between a proc and a lambda in Ruby?