Do we really need the [[HasOwnProperty]] internal method and hasOwn trap

Brendan Eich brendan at
Mon Nov 19 03:37:06 PST 2012

David Bruant wrote:
> So my position is let's not bake performance bottlenecks in the 
> language (which we tend to do naturally anyway) and for things that 
> can be optimized, let's say that the implementations will pay the cost 
> of the static/runtime analysis if it's really felt by them like a 
> worthwhile idea. 

No, sorry. Allocations will always cost. It's unphysical to argue 
otherwise. I've been burned too many times by this, even if it's a small 
constant overhead. Those add up, as David Bacon used to point out to 
good effect.


More information about the es-discuss mailing list