paultopia/clojurec

A Clojure implementation on top of C

ClojureC

This is compiler for the Clojure programming language that targets C as a backend. It is based on ClojureScript and was started off ClojureScript's commit 0e0aa7fdd379649bf87f8fff5c6a64e37fe616a4.

Community and Organization

We use a Trello board to keep track of ideas, proposals, TODOs, bugs and who's doing what. If you plan to contribute, please do join the board.

Additional documentation for the project can be found at the wiki.

Preparations

Submodules

ClojureC includes a submodule. To fetch it, do

git submodule init
git submodule update

Dependencies

Before you can run anything make sure you have GLib 2 and the Boehm-Demers-Weiser garbage collector installed. If

pkg-config --cflags glib-2.0
pkg-config --cflags bdw-gc

don't report errors you should be good.

Make sure you're using Leiningen 2 - older versions of Leiningen won't work. Run the testsuite:

lein test

All tests should pass.

Using ClojureC

Note that ClojureC is still in its experimental phase, so please don't expect a polished experience, yet.

From the command line

ClojureC provides a very simple command line compiler interface. Let's say we want to compile samples/echo.cljc:

(ns cljc.user)
(defn -main [& args]
  (apply println args))

If you do the following in the clojurec directory

lein run -c src/cljc/cljc/core.cljc cljc.core run run
lein run -c samples/echo.cljc cljc.user run run
lein run -d cljc.user/-main run
cd run
make

you should have a cljc executable in the run directory that acts mostly like echo.

Objective-C bridge

ClojureC features a very rudimentary Objective-C bridge. Here's an example:

(ns cljc.user
  (:require [cljc.objc :as objc]))

(extend-type (§ NSString)
  ICounted
  (-count [self]
    (§ self length)))

(defn -main [& args]
  (let [app (§ (§ NSApplication) sharedApplication)
        date (§ (§ NSDate) :dateWithTimeIntervalSinceNow 3600)
        locale (§ (§ NSLocale) currentLocale)
        desc (§ date :descriptionWithLocale locale)]
    (println "Hello, NSApplication: `" desc "` has count " (count desc))))

If you have that code in /tmp/nsdate.cljc, then this will build and run it:

lein run -c src/cljc/cljc/core.cljc cljc.core run run
lein run -c src/cljc/cljc/objc.cljc cljc.objc run run -m
lein run -c /tmp/nsdate.cljc cljc.user run run -m
lein run -d cljc.user/-main run -m
cd run
make

For a more involved example, see samples/ios.cljc.

iOS sample app

To build the iOS sample app, do

cd samples
./build-ios.sh

The last step will open an XCode project that will build and run the iOS app that build-ios.sh compiled from samples/ios.cljc.

From the REPL

The easiest way to play around with ClojureC interactively is in the namespace clojurec.core-test. For example:

(core-run '(pr (+ 1 2)))
=> [3]

Mobile Platform Notes

Android

See the README.md file in "clojurec/run/android".