Charles Oliver Nutter wrote:
> It slows down JRuby a bit more than Ruby 1.8, unfortunately, because of 
> the way the JVM manages exception handling and operand stacks. But 
> generally you won't notice it, since nontrivial code bodies will be 
> quite a bit faster than 1.8.

Actually, it just occurred to me that this is entirely a factor of local 
variable handling; when rescue is involved, JRuby has to switch from 
stack-based local variables to heap-based local vars. I'm working on a 
few ways to mitigate this cost for the general case, so this perf hit 
may go away.

- Charlie