Figwheel tools will eventually hold much of Figwheel's functionality in separate composable libraries, (i.e. compile, error/warning parsing etc.)
For now, it only holds the support for figwheel.tools.nrepl which is a drop in
replacement for piggieback.
piggieback has one known flaw, it instantiates a new ClojureScript
REPL on every eval request. Creating a CLJS REPL is a particularly
heavy operation. It involves, at the very least, the reloading of the
analysis cache and this causes a noticeable lag on each evaluation. In
my experience the lag is close to 1 second.
figwheel.tools.nrepl creates a single CLJS REPL on a thread and is much
more responsive and lighter as a result. It also handles more of the nREPL
protocol's features.
figwheel.tools.nrepl provides an instantaneous response to forms
submitted for evaluation.
For example it can handle multiple forms
;; Multiple forms are evaluated:
=> 1 2 (+ 1 2) 4
1
2
3
4
=>
You can also interrupt a hung evaluation:
;; Interrupting a hung evaluation
=> (loop [] (recur))
;; now reload the current page that hosts the REPL
^C
;; control is returned to the REPL which is actually running in
;; a new runtime
=>
figwheel.tools.nrepl handles the ClojureScript I/O as explicit
messages and can leverage these explicit messages to create a better
ClojureScript nREPL experience.
Modify your project.clj to include the following :dependencies and :repl-options:
:profiles {:dev {:dependencies [[figwheel.tools "0.1.0-SNAPSHOT"]]
:repl-options {:nrepl-middleware [figwheel.tools.nrepl/wrap-cljs-repl]}}}
In your nREPL environment you can now start a CLJS REPL
$ lein repl
....
user=> (figwheel.tools.nrepl/cljs-repl (cljs.repl.nashorn/repl-env))
To quit, type: :cljs/quit
nil
cljs.user=> (defn <3 [a b] (str a " <3 " b "!"))
#<
function cljs$user$_LT_3(a, b) {
return [cljs.core.str(a), cljs.core.str(" <3 "), cljs.core.str(b), cljs.core.str("!")].join("");
}
>
cljs.user=> (<3 "nREPL" "ClojureScript")
"nREPL <3 ClojureScript!"
Copyright © 2017 Bruce Hauman
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.