TaggedArrays (Proposal)

[Dain Sundstrom]

Wow.  That dramatically changes my mental model of exceptions in the JVM.  This is going to dramatically simplify some of my code.

thanks

-dain

On Jul 7, 2012, at 11:48 AM, Vitaly Davidovich wrote:

> Here's a blog post from John Rose explaining that exception throwing compiles to a goto in cases like this: 
> https://blogs.oracle.com/jrose/entry/longjumps_considered_inexpensive
> 
> Sent from my phone
> 
> On Jul 7, 2012 2:43 PM, "Rémi Forax" <forax at univ-mlv.fr> wrote:
> On 07/07/2012 07:02 PM, Dain Sundstrom wrote:
> > On Jul 7, 2012, at 1:56 AM, Rémi Forax wrote:
> >
> >> You have also to figure out how to get two return values from a method call,
> >> but exceptions are your best friend here.
> > Can you give an example of what you mean here?  Also, from all the presentations I've seen on the JVM, exceptions are very expensive to throw and catch, so I would expect this to be way slower then say returning the multiple values using a generated results class.
> 
> Exception are not expensive if you throw them and just catch them (and
> don't use them) in the same inlining horizon,
> so you can use them to implement non Java control flow without thinking
> too much.
> 
> Anyway, the idea here is to use exception as an exceptional mechanism by
> example when
> something that should be an int is not. In that case, throwing an
> exception is not a big deal
> because the VM will have to deopt which usual have a bigger impact on
> the run time.
> 
> >
> > -dain
> 
> Rémi
> 
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