cljs-repl

cljs-bootstrap

This project uses bootstrapped ClojureScript to implement node.js and web ClojureScript REPLs. The bootstrapped aspect means that the REPLs run using only JavaScirpt files (i.e. without a JVM).

Note: this was originally a fork of https://github.com/swannodette/cljs-bootstrap

This is a work in progress and many things work but there are still bugs (see examples below).

Just the REPL please

If you just want to the bootstrapped ClojureScript REPL, you try the web version at clojurescript.net or you can download a pre-built Node.js version and run it like this:

curl https://gist.githubusercontent.com/kanaka/b588dbb6d44174672cc2/raw/repl-node.js > clojurescript.js
chmod clojurescript.js
./clojurescript.js

Build the REPL

To build the bootstrapped REPL, follow these steps:

• First, check out the repositories:

git clone https://github.com/clojure/clojurescript
git clone --branch cljs-bootstrap https://github.com/swannodette/tools.reader
git clone https://github.com/kanaka/cljs-bootstrap

• Build and install the regular ClojureScript compiler and patched reader:

cd clojurescript
time ./script/build
# Note the version of ClojureScript that is built. 
cd ..
 
cd tools.reader
lein install
cd ..

• Update the cljs-bootstrap project.def with the version of ClojureScript that was built above and then install Node/npm dependencies (source-map-support and readline-sync):

cd cljs-bootstrap
vi project.def # update to correct ClojureScript version 
lein npm install

• Bootstrap build the ClojureScript compiler and simple REPL (this compiles to JavaScript in the .cljs_bootstrap/ directory):

time lein run -m clojure.main script/build.clj

• Run the REPL using a Node launch script:

node repl.js

• Optionally, you can now build/compile the sources into a single standalone JavaScript file repl-node.js (as per the gist above).

  • First you need to download and unzip the Google Closure compiler jar file:

wget http://dl.google.com/closure-compiler/compiler-latest.zip
unzip compiler-latest.zip

• Now generate the standalone all-in-one REPL files for node.js (repl-node.js) and the web (repl-web.js):

./script/gen_single.sh

• Run the standalone all-in-one REPL:

./repl-node.js

Dynamic namespace loading

To load/evaluate arbitrary libraries/namespaces you must first configure the search path. For example, to load the "joel.core" namespace from src/joel/core.cljs, you need to configure the loader like this:

cljs.user> (cljs-bootstrap.repl/set-load-cfg :lib-base-path "src/")

Now you can load it and use it like this:

cljs.user> (ns foo.bar (:require joel.core))
foo.bar> (joel.core/some-fn 1 2 3)

Macros are supported by bootstrapped ClojureScript but they still must live in a separate file from regular ClojureScript code and are loaded using :require-macros.

Examples

• Try some code that works:

cljs.user> :foo 
:foo 
cljs.user> 123 
123 
cljs.user> (+ 2 3) 
5 
cljs.user> (second [2 3 4]) 
3 
cljs.user> ( (fn [a b] (* a b)) 3 4) 
12 
cljs.user> ( #(* %1 %2) 4 5) 
20 
cljs.user> ( #(* %1 %2) 4 5) 
20 
cljs.user> (do (prn :foo) (prn :bar) :baz) 
:foo 
:bar 
:baz 
cljs.user> (def x 3) 
#'cljs.user/x 
cljs.user> (def foo (fn [a b] (* a b))) 
#'cljs.user/foo 
cljs.user> (foo 6 7) 
42 
cljs.user> (defn bar [a b] (* a b)) 
#'cljs.user/bar 
cljs.user> (bar 7 8) 
56 
cljs.user> (let* [x 7 y (+ 1 x)] y) 
8 
cljs.user> (meta (with-meta [2 3 4] {:a 123})) 
{:a 123} 
cljs.user> (let [[x y] [3 4] z (+ x y)] (* x y z)) 
84 
cljs.user> (and 1 2 3 4) 
4 
cljs.user> (map #(.toUpperCase %) ["hello" "allcaps" "world"]) 
("HELLO" "ALLCAPS" "WORLD") 
cljs.user> (.toString (reify Object (toString [this] "hello"))) 
"hello" 
cljs.user> (defprotocol IFoo (foo [this])) 
nil 
cljs.user> (foo (reify IFoo (foo [this] (prn "lots of foo")))) 
"lots of foo" 
nil 
cljs.user> (deftype Bar [] IFoo (foo [this] (prn "some bar too"))) 
cljs.user/Bar 
cljs.user> (foo (Bar.)) 
"some bar too" 
nil 
cljs.user> (defrecord Baz [b] IFoo (foo [this] (prn "some baz:" b))) 
cljs.user/Baz 
cljs.user> (foo (Baz. 5)) 
"some baz:" 5 
nil 
cljs.user> (ns foo.bar (:require [hello-world.core]) (:require-macros [hello-world.macros])) 
"prn from inside hello-world.core" 
"prn from inside hello-world.macros" 
nil 
cljs.user> (hello-world.core/mult-fn 2 3) 
6 
cljs.user> (hello-world.macros/mult-macro 7 8) 
56 
cljs.user> (doc map) 
------------------------- 
 
([f] [f coll] [f c1 c2] [f c1 c2 c3] [f c1 c2 c3 & colls]) 
... 
 

• Try some things that do not work yet:

cljs.user> (require ['hello-world.core]) 
/home/joelm/scratch/cljs-bootstrap/.cljs_bootstrap/cljs/core.cljs:8272 
      x 
      ^ 
Error: Doesn't support name: 
... 
 

License

Copyright © 2015 David Nolen, Rich Hickey, Joel Martin & Contributors

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.