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. I agree that we shouldn't make decision on the current state. (FWIW I think that exceptions should only be used for "exceptional" cases.) _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
