Allen's lambda syntax proposal

[Maciej Stachowiak]

On Dec 5, 2008, at 11:12 PM, Jon Zeppieri wrote:

>
> I don't get it.  What issue is raised by return-to-label that isn't
> already raised by exceptions?  They're practically the same thing,
> only return-to-label is *easier* to analyze statically, because
> 'return' can only jump to a label that is lexically (not just
> dynamically) in scope.

If you want to call a function and make sure control flow does not  
escape, then in the face of exceptions alone you can wrap it in try/ 
catch. However, with multi-level returning lambdas, if you are passed  
a function then you have no way to prevent it from returning early,  
since it could be a lambda in the lexical scope of your caller.

Regards,
Maciej