> On 28 Nov 2017, at 02:33, Jiacai Liu <[email protected]> wrote: > > > Also, most of the performance boost from transducers is due to less garbage > > being created, and some times the heap of the JVM is so large you'll never > > see much change from switching to transducers. > > Thanks for this tip. I seldom use transducers in my daily work, and I was > convinced transducers are a better choice in whatever situation after reading > some articles. But the test shows it isn't an easy choice, only when do > something reducible, will transducers make more sense.
If you're going for pure speed (such as, you have functional use cases to make the application faster) you shouldn't take them from granted. It's true that they might be faster option in many situations, but you should always benchmark it. Missing the pure speed requirement, I'd use them as the default option, reducible or not. I prefer the flexibility they offer out of the box, the fact that I can stack up xducers as I need and then refactor/compose them out, when and if it makes sense. As a bonus, I like the fact that transducers let me turn off caching of lazy seqs (eduction) or fold a stateless chain in parallel. IMHO, it's more flexible option to grant default use. Renzo > > On Tuesday, November 28, 2017 at 5:07:10 AM UTC+8, tbc++ wrote: > >> Also, I think the transducer version should always be faster, no matter > >> the size of the source collection (no threshold). > > It's a bit more complicated than that, mostly because transducer pipelines > require about 2 allocations per step during creation. Also, most of the > performance boost from transducers is due to less garbage being created, and > some times the heap of the JVM is so large you'll never see much change from > switching to transducers. > > Don't get me wrong, transducers are great and I often default to them over > seqs, but in micro-benchmarks like this there's too much in play to always > see a 100% performance boost. > > On Mon, Nov 27, 2017 at 12:55 PM, David Bürgin <[email protected]> wrote: > Jiacai – > > I saw you updated the gist. Just in case it passed you by: performance > profits from the source collection being reducible. So pouring ‘dataset’ > into a vector beforehand should speed up the processing quite a bit. > > Also, I think the transducer version should always be faster, no matter > the size of the source collection (no threshold). > > > -- > David > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to [email protected] > Note that posts from new members are moderated - please be patient with your > first post. > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > > > > -- > “One of the main causes of the fall of the Roman Empire was that–lacking > zero–they had no way to indicate successful termination of their C programs.” > (Robert Firth) > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to [email protected] > Note that posts from new members are moderated - please be patient with your > first post. > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to [email protected] Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
