The implementation of iterators in C# and its consequences (part 3)

re: The implementation of iterators in C# and its consequences (part 3)

Professor Farnsworth — Thu, 14 Aug 2008 17:14:50 GMT

Good news everyone! CLR week is almost over!

re: The implementation of iterators in C# and its consequences (part 3)

Bob — Thu, 14 Aug 2008 18:10:35 GMT

I want more CLR week! GIME GIME GIME. :)

re: The implementation of iterators in C# and its consequences (part 3)

Eric Lippert — Thu, 14 Aug 2008 19:29:16 GMT

It is, as you note, a hard problem, so hard that we on the compiler team have gotten it wrong numerous times. I apologize for the inconvenience.

There are scenarios where you can have multiple nested try blocks and the released v3 compiler generates code that runs the finally blocks outside-to-inside instead of the correct order.

I believe we have fixed those bugs for the v3 service release, but we have found more since then.

(So far the only remaining bugs I know of involve bizarre cases of, say, a yield break which branches out to a finally which then executes a second yield break. The control flow can get messed up in complicated circumstances like that.)

If anyone finds bugs involving iterators blocks and finally execution, please email me via my blog.

re: The implementation of iterators in C# and its consequences (part 3)

Daniel Plaisted — Thu, 14 Aug 2008 21:17:52 GMT

Was support for try blocks with yield statements inside them added in VS2008? I tried to do this in VS2005 and the compiler told me that it wasn't supported, so I had to work around it. It was kind of a pain.

re: The implementation of iterators in C# and its consequences (part 3)

Daniel Plaisted — Thu, 14 Aug 2008 21:23:16 GMT

Regarding my previous comment, it looks like the limitation I was remembering was that you cannot yield a value in the body of a try block with a catch clause. You also can't yield a value within a catch clause.

I assume there are good reasons for this but for my situation it would have been nice if it worked :)

Today’s Blogs « Roman’s Blog

Today’s Blogs « Roman’s Blog — Thu, 14 Aug 2008 23:11:38 GMT

PingBack from http://rhnatiuk.wordpress.com/2008/08/14/todays-blogs/

re: The implementation of iterators in C# and its consequences (part 3)

Jack Mathews — Fri, 15 Aug 2008 00:28:17 GMT

If you don't Dispose the iterator, will the finalizer cause the code in the finally blocks to get executed?

Visual Studio Links #66

Visual Studio Hacks — Mon, 18 Aug 2008 14:55:52 GMT

My latest in a series of the weekly, or more often, summary of interesting links I come across related to Visual Studio. Greg Duncan posted a link to the release announcement for Task Board for Team System Beta 2 . Raymond Chen discussed the implementation

Interesting Links – 8/21/2008

Matt Johnson's Technical Adventures — Thu, 21 Aug 2008 22:21:16 GMT

The Old New Thing : The implementation of iterators in C# and its consequences (part 3) Notes from a

C# Yield Keyword « Vasu Balakrishnan’s Blog

C# Yield Keyword « Vasu Balakrishnan’s Blog — Wed, 20 May 2009 22:36:07 GMT

PingBack from http://vasubalakrishnan.wordpress.com/2009/05/20/c-yield-keyword/