[whatwg] Script loading and execution order for importScripts
Oliver Hunt
oliver at apple.com
Sat Mar 7 12:54:13 PST 2009
Yes, i realise it does more than _just_ a syntax check, but the user
observable effect is just the success or failure of syntax check :D
--Oliver
On Mar 7, 2009, at 12:51 PM, Boris Zbarsky wrote:
> Oliver Hunt wrote:
>> If by "compilation" you mean you're (effectively) just doing a
>> syntax check then webkit is able to this, although it has a
>> reasonable cost associated with it
>
> "Compilation" in this case is parsing and compilation to
> SpiderMonkey bytecode. This does include syntax checks, of course,
> but also an optimization pass (constant folding, some simple dead
> expression elimination, that sort of thing) and produces the actual
> object that can be executed (which is quite distinct from the
> character array that is input to the compilation process).
>
> This is not a trivial cost at the moment: it's about 10-20% of the
> cost of loading and executing some of the large scripts out there
> which have all sorts of function definitions but don't immediately
> run all the code (e.g. the scripts loaded by gmail).
>
> -Boris
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