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
This project is no longer actively maintained, though PRs and such are still welcome.
Background, Features, and Limitations
Forked off of a version of ClojureScript circa 2012 (prior to Clojure and ClojureScript being refactored to use the same compiler or front end), ClojureC provides:
Generation of C or Objective-C code, enabling faster startup than JVM-based executables
Objective-C message sending uses the section character (§) in place of the at-sign (@), as the latter is already used by Clojure.
Ability to statically expose any C function to ClojureC (dynamic loading might be possible but is not currently implemented)
An implementation of the Boehm Garbage Collector (GC)
Incomplete support for native threads
Exception handling currently uses two global variables (could be replaced with thread-local vars?).
Extending protocols might also not be threadsafe.
No support for "modern" Clojure language features such as transducers
Limited optimization, really only as demanded by the language
For example, loop/recur is turned into a real loop.
Implemented via setjmp/longjmp.
Alternatives to ClojureC
If native threads are not important, but fast startup is, consider using ClojureScript instead of ClojureC, as the startup time for the v8 engine is reportedly much faster than for the JVM.
As there seem to be few known use cases for programs that need to both start up quickly and use native threading, it is perhaps not surprising that there's little apparent interest in making the necessary changes to "productize" ClojureC. Such changes could include:
Full support for native threads
Supporting the latest version of the Clojure language
Supporting a C++ back end
Retargeting the GCC compiler back end
Implementing a proper optimizer
Providing improved debugger support
Other than (perhaps) full native-thread support, each of the above item would represent a substantial investment of resources that are not, at present, available.
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.
ClojureC includes a submodule. To fetch it, do
git submodule init git submodule update
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:
All tests should pass.
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
(ns cljc.user) (defn -main [& args] (apply println args))
If you do the following in the
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 -f c/Makefile
you should have a
cljc executable in the
run directory that acts mostly like
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
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
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))) => 
Mobile Platform Notes
See the README.md file in "clojurec/run/android".