Error Handling - Resumable Exceptions

[Humberto Anjos]

Since Magpie isn't totally novel, but unusual in some ways (munificent's words, not mine :)), I wonder if any thought has been given to some form of resumable exceptions, like Common Lisp's condition system. It enables some interesting patterns, such as Abort, Retry, Ignore, at the method level. Some links about CL's conditions:

• http://www.gigamonkeys.com/book/beyond-exception-handling-conditions-and-restarts.html 
  
• http://www.nhplace.com/kent/Papers/Condition-Handling-2001.html 
  
• http://en.wikibooks.org/wiki/Common_Lisp/Advanced_topics/Condition_System 
  

[Bob Nystrom]

I am definitely interested in resumable exceptions (and, possibly,
continuations). I don't have any first-hand experience with them in
other languages, but they're on my list of features to learn more
about.

- bob

[Humberto Anjos]

Yay for resumable exceptions! \o/

About continuations... The amount of stuff you can do with them is awesome, but I'm not so sure that putting what essentially is goto as a first-class value in the language is that good of an idea... Do you have any specific use cases in mind that continuations would be the most elegant solution? Lua's mailing list has some discussion on why Lua should/doesn't have continuations, and Roberto (Lua's chief architect) argues that Lua's coroutines are easier to implement than full continuations and solve most of the problems you would use continuations for: http://books.google.com.br/books?id=jaNmjhYiM0oC&pg=PA2&lpg=PA2&dq=lua+list+continuations&source=bl&ots=muW7du_xIt&sig=bcmwHH7aVwmb3rccPOOBhSfmWNk&hl=pt-BR&sa=X&ei=8lcRT6vpF8ectwf70fn7Ag&ved=0CHgQ6AEwCA#v=onepage&q=lua%20list%20continuations&f=false