From: matz@... (Yukihiro Matsumoto)
Date: 2003-08-04T11:40:47+09:00
Subject: Re: Home grown continuations

Hello,

In message "Re: Home grown continuations"
    on 03/08/03, Jim Weirich <jweirich@one.net> writes:

|> Since 1.8, return within the closures created by proc or lambda, just
|> terminates the closure execution.  
|
|Huh?  I'm not sure I am understanding.  What should the following
|return?
|
|  def x
|    10.times { |n| return 1 if n == 5 }
|    2
|  end
|  p x
|
|I would expect 1, but you seem to be saying 2.

It would be 1.  Don't worry.  It's not created with proc nor lambda.

|> If you create a closure by
|> Proc.new, it causes error, since call frame information is already
|> lost unlike callcc.
|
|So Proc.new is different?  What about the following code?
|
|  def y
|    p = Proc.new { |n| return 1 if n == 5 }
|    10.times(&p)
|    2
|  end
|
|Again, I would expect 1, but you seem to be saying it will be an error.

It would be 1 again.  It causes error when the call frame is lost.  In
your example, the method created a proc still running so that the call
frame exists too.

							matz.