I am using ruby 1.8.7.

p = lambda { return 10;}
def lab(block)
  puts 'before'
  puts block.call
  puts 'after'
end
lab p

Above code output is

before
10
after

I refactored same code into this

def lab(&block)
  puts 'before'
  puts block.call
  puts 'after'
end
lab { return 10; }

Now I am getting LocalJumpError: unexpected return.

To me both the code are doing same thing. Yes in the first case I am passing a proc and in the second case I am passing a block. But &block converts that block into proc. So proc.call should behave same.

And yes I have seen this post http://stackoverflow.com/questions/2325471/using-return-in-a-ruby-block