This is a nice trick and its one I have done myself on Clojure CLIs (particularly with "help" options) to defer loading and give a faster feel to startup. It is great to have a repl that starts super fast for people learning Clojure to get started, or to spin one up to try something.
However, the time to start up a base Clojure repl (with no deps or app code) is already subsecond - so you're saving no more than a second with this approach. The problem is that (approximately) no one actually starts a REPL this way. [You can find my ongoing notes on this subject at http://dev.clojure.org/display/design/Improving+Clojure+Start+Time by the way.] Most people start a REPL via Leiningen (or Boot), and the demo'ed technique changes nothing about that experience. Leiningen still needs to start the Clojure runtime, compile and load nrepl and all the tooling, launch an nrepl server in a new JVM, connect to it, load all the middleware code, and commonly even a vast amount of application code (based on common patterns of project setup). If you look at the Luminus guestbook application for example (not picking on this one, just one I happened to look at), at dev time it loads env/dev/clj/user.clj prior to repl startup which loads a vast number of dependency namespaces and application code, which takes 10s of seconds, which dwarfs Clojure core load time. Because this a Clojure repl hack, it also does nothing to affect actually running a Clojure application, which again must load the Clojure runtime and your application code (which often involves compiling and loading a lot of code) before it starts doing anything. So while this is a nice demo, I don't see that it actually changes anything for the vast majority of actual "Clojure start time issues" people experience on a daily basis. That said, this is an acknowledged pain point that we still care about very much! I'm sure there will be more work on this to come. On Saturday, June 18, 2016 at 9:25:37 PM UTC-5, Sungjin Chun wrote: > > Yes, I want this kind of instant speed (I hope this kind of speed is > possible in > emacs + side). > > https://www.youtube.com/watch?v=D3gpQth8uTI&feature=youtu.be > > Have you seen this? Why we simply cannot do this? > -- 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.
