- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Thu, 08 Aug 2013 01:55:52 -0400
- To: Jonas Sicking <jonas@sicking.cc>
- CC: Domenic Denicola <domenic@domenicdenicola.com>, public-script-coord@w3.org
On 8/8/13 1:52 AM, Jonas Sicking wrote: > Couldn't we still implement such a method by having specially generated > code which did type testing specifically by doing checks similar to what > Array.isArray does? I.e. we would generate wholly different type testing > code than we do for (other) DOM objects. It depends on whether we even have a way to tell some Arrays apart from others internally. Right now, SpiderMonkey (for example) doesn't allow an embedding to do that. If we posit that that's changed, introducing basically a separate kind of DOM object that doesn't behave like all the others is possible, but would slow down some things (more branching) and would require a bunch more work to make it play nice with the JIT (because it doesn't have the same internal layout as other objects the JIT knows about). So as I said, doable at significant performance cost. -Boris
Received on Thursday, 8 August 2013 05:56:22 UTC