- From: Ian Hickson <ian@hixie.ch>
- Date: Tue, 1 May 2012 06:26:40 +0000 (UTC)
On Mon, 30 Apr 2012, Ryosuke Niwa wrote: > > > > Seems like it'd be better just to have UAs optimise their JS string > > implementations so that it can just be backed by the same thing as the > > DOM or the control's editor. (I believe Mozilla may in fact already do > > that.) > > In theory, this is possible. But any sort of proxy, etc... that lazily > obtain the value (e.g. delaying it until substr, etc... is called) is > hard to implement in practice because we need to serialize text before > DOM is modified. e.g. > > 1 var inputValue = input.value; > 2 var textUsed = input.value.substr(5, 10); > > In the above example, inputValue could be a proxy object. However, in > the example below: > > 1 var inputValue = input.value; > 2 input.value = 'bar'; > 3 var textUsed = input.value.substr(5, 10); > > we need to serialize the string immediately before the statement in the > line 2 is evaluated. That's just copy-on-write. It's hardly rocket science. :-P -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Monday, 30 April 2012 23:26:40 UTC