Jon Zeppieri wrote: > On Sat, Dec 6, 2008 at 11:49 AM, Maciej Stachowiak <[EMAIL PROTECTED]> wrote: >> On Dec 5, 2008, at 11:12 PM, Jon Zeppieri wrote: >> >>> I don't get it. What issue is raised by return-to-label that isn't >>> already raised by exceptions? [...] > Also, what was the performance issue?
The (minor) performance issue is that if there is a lambda that returns from a given function, all calls within that function body must check for an escape, even if the lambda is never passed to them or otherwise accessible to them. Similarly for calls within the scope of a labelled statement or iteration that contains a lambda with a corresponding 'break' or 'continue'. Exceptions, OTOH, are implementable without an explicit check on each function call. Just this performance issue on its own wouldn't be significant -- it might matter in a language that is otherwise highly optimizable, but not in ECMAScript. I'll address the safety issue separately. -- David-Sarah Hopwood _______________________________________________ Es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
