Ruby代码
def gen_times(factor)
  return Proc.new {|n| n*factor }
end

times3 = gen_times(3)
times5 = gen_times(5)

times3.call(12)               #=> 36
times5.call(5)                #=> 25
times3.call(times5.call(4))   #=> 60

Ruby代码
a_lambda = lambda {|a| puts a}
a_lambda.call("samsam")

 lambda返回的是一个Proc对象。

Ruby代码

a_lambda.class #=>Proc

 lambda和Proc是一样的，除了Proc的return会跳出调用的方法，lambda则不会，它只是返回自己。

def foo  
    f = Proc.new { return "return from foo from inside proc" }  
    f.call # control leaves foo here  
    return "return from foo"   
  end  
    
  def bar  
    f = lambda { return "return from lambda" }  
    puts f.call # control does not leave bar here  prints "return from lambda"
    return "return from bar"   
  end  
    
  puts foo # prints "return from foo from inside proc"   
  puts bar # prints "return from bar"