Separate regular and CIDER repls in Boot

Until now, Boot documentation had imperfect instructions on how to setup Boot to fully work with CIDER. I've updated the page to include a better way which separates regular repl (launched from terminal, better be quick to load) from the heavy CIDER repl with all the necessary dependencies. Here we go, add this code to ~/.boot/profile.boot:

(require 'boot.repl)

(deftask cider ""
  (reset! boot.repl/*default-dependencies*
         '[[org.clojure/tools.nrepl "0.2.12"]
           [cider/cider-nrepl "0.10.0"]
           [refactor-nrepl "2.0.0-SNAPSHOT"]])
  (reset! boot.repl/*default-middleware*

Then in Emacs do M-x customize-variable cider-boot-parameters and set it to cider repl -s wait.

Now, if you compare the loading time of two REPLs:

$ time boot cider repl -s
boot cider repl -s  32.92s user 1.20s system 210% cpu 16.182 total

$ time boot repl -s
boot repl -s  12.71s user 0.37s system 242% cpu 5.385 total

That's 5 versus 16 seconds! Quite significant, especially if you just want to quickly check something in the REPL from the terminal.


Tasks can be used in Boot to imitate profiles in Leiningen. We have created a cider task which only changes some configuration inside Boot and delegates work to the next task. So boot cider repl would be roughly equivalent to lein with-profiles cider repl had we a similar :cider profile in Leiningen.

Boot still feels a little bit unpolished, but I think I will eventually migrate to it completely, and for good reasons. I plan to write an extensive entry soon about why I like the Boot approach over the Leiningen approach. Stay tuned!