- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Fri, 10 Feb 2012 10:20:42 -0500
- To: www-style@w3.org
On 2/10/12 8:36 AM, Lea Verou wrote: > On 10/2/12 12:07, François REMY wrote: >> * it recognizes both "-beta-property" and >> "-vendor-property" as aliases : > > I was under the impression that such aliases consume extra memory (as > they need to be present on every instance) and thus vendors are trying > to avoid them. I think it really depends on how they're required to behave. If the aliases are pure parse-time aliases (as in, they just both get treated as "property" internally, last one set wins, etc), then supporting them is pretty low overhead. You just have to have a mapping from alias to real property name, and there is no extra storage involved otherwise. You can see the entirety of the code and data needed to add such aliases in Gecko at <http://hg.mozilla.org/mozilla-central/rev/8adb2f64c138>. If there were a lot of aliases, a bit more complexity may be involved to replace the linear scan with a hashtable lookup, but it wouldn't be a huge deal. If the aliases have some sort of complicated cascading behavior, then things get worse. The longer the separate data needs to be kept, the worse it is. The worst case, of course, would be if both aliases are required to be present in computed style and then the "right" one is picked for used style. -Boris
Received on Friday, 10 February 2012 15:21:15 UTC