My mental model explains most of this away due to the different load patterns of java vs v8. In JVM clojure, functions are essentially 1:1 with classes, so in a functional language and standard lib, that's a lot of classes. Java will eagerly classload your entire app and deps before doing any work. V8 takes an upfront hit on parsing into javascript, but the JS target fits the structure of clojure itself much more closely. More time (not sure how much compared to JVM) will be spent JITing hot code paths, but that won't show up in the startup cost.
You can get JVM clojure REPL startup a little faster by AOT compiling all your deps, but it's generally not worth it in a development flow. I think lumo does some extra tricks to keep this upfront cost down that are v8-specific: https://anmonteiro.com/2016/11/the-fastest-clojure-repl-in-the-world/ On Fri, Jul 14, 2017 at 6:20 PM Didier <didi...@gmail.com> wrote: > This link: > https://dev.clojure.org/display/design/Improving+Clojure+Start+Time says > that the Java startup time is ~94 ms, while Clojure boot time is ~640 ms. > That's a ~680% increase. > > On my machine the java start time is: ~1042 ms, and the Clojure start time > is around ~3108 ms. A ~298% increase. > > When I time the startup time of lumo against node, I get ~1190 ms for > node, and ~1523 ms for lumo. A ~128% increase only. > > Does Clojure perform more initialization then ClojureScript? And would > that explain the much higher overhead Clojure has on top of the JVM, versus > ClojureScript? > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > 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 clojure+unsubscr...@googlegroups.com. > 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 clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com 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 clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
