On Wed, Jun 4, 2014 at 1:17 AM, Rik Cabanier <caban...@gmail.com> wrote:
> > > > On Tue, Jun 3, 2014 at 3:48 PM, Till Schneidereit < > t...@tillschneidereit.net> wrote: > >> On Wed, Jun 4, 2014 at 12:26 AM, Rik Cabanier <caban...@gmail.com> wrote: >> >>> > Actually, inverse() is already spec'd to throw if the inversion fails. >>> In >>> > that case (assuming we keep it that way) there is no need at all for >>> any >>> > isInvertible kind of method. Note that in floating-point arithmetic >>> there >>> > is no absolute notion of invertibility; there just are different matrix >>> > inversion algorithms each failing on different matrices, so >>> "invertibility" >>> > only makes sense with respect to one inversion algorithm, so it is >>> actually >>> > better to keep the current exception-throwing API than to introduce a >>> > separate isInvertible getter. >>> > >>> >>> That would require try/catch around all the "invert()" calls. This is >>> ugly >>> but more importantly, it will significantly slow down javascript >>> execution. >>> I'd prefer that we don't throw at all but we have to because SVGMatrix >>> did. >>> >> >> That isn't really true in modern engines. Just having a try/catch doesn't >> meaningfully slow down code anymore. If an exception is actually thrown, a >> (very) slow path is taken, but otherwise things are good. >> >> (I can only say this with certainty about SpiderMonkey and V8, but would >> assume that other engines behave similarly. And even if not, it doesn't >> make sense to make decisions like this based on their current performance >> characteristics.) >> > > Interesting! > I wrote a small experiment: http://jsfiddle.net/G83mW/14/ > Gecko is indeed impervious but Chrome, Safari and IE are not. V8 is > between 4 and 6 times slower if there's a try/catch. > Ah, I stand corrected on V8, then. I know that they have some optimizations in place for try/catch, but they're apparently less effective than ours. I'm sure it's only a matter of time until this stops causing slowdowns in any engine. > > I agree that we shouldn't make decision on the current state. (FWIW I > think that exceptions should only be used for "exceptional" cases.) > That's true, yes. Also, given that you all would rather not have exceptions here for other reasons, this seems to all be moot anyway. :) _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
