Use of long in Nashorn

Hannes Wallnoefer hannes.wallnoefer at
Sun Dec 6 10:27:53 UTC 2015

Am 2015-12-06 um 11:12 schrieb Hannes Wallnoefer:
>> * array length: could we still have Nashorn APIs that return long? 
>> Optimistic filters will deal with these appropriately, won’t they? I 
>> guess they should since they also need to be able to handle return 
>> values from POJO methods that return long (e.g. 
>> System.currentTimeMillis()). Hence, you could have NativeArray.length 
>> return “long” and let the optimistic machinery decide whether to cast 
>> it as int or double. That would allow you to not have to box the 
>> return value of NativeArray.length.
> Yes, we could have things returning long, but it will deoptimize to 
> Object. OptimisticReturnFilters (which do the runtime checks) are not 
> used for ScriptObject properties.

Actually it would still be nice not to box, which probably means we have 
to make it optimistic. Looking at this, I found that we have an 
@Optimistic annotation but it looks like it isn't actually used nor 


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