clojure-scheme

Pervasive tail-call optimization anyone?

A few cosmetic changes to the lovely ClojureScript compiler and we are producing output suitable for compilation to C via Gambit Scheme!

Clojure/West 2013 hosted a talk introducing clojure-scheme. The slides are online and the corresponding video will be made available this August.

Getting Started

The fastest way to get started is to try the self-hosted clojure-scheme REPL:

1. Install Gambit Scheme from source or from an OSX/Win32 installer.
2. Put gsc on your PATH (make install puts gsc in /usr/local/Gambit-C/bin by default).
3. Install Leiningen.
4. git clone https://github.com/takeoutweight/clojure-scheme.git
5. In the root clojure-scheme directory, run lein install
6. In the samples/repl directory, run lein run to build the self-hosted REPL. (src/build.clj demonstrates how to compile .clj files to scheme code).
7. run sh run-clojure-repl to launch the REPL, and enter (install-clojure-repl) to switch from Scheme mode to Clojure mode.

Performance

Gambit seems to be a promising compile target for Clojure:

			(scm* [] (load "core"))
			(ns bench)
			(defn fib [n]
				 (if  (or (identical? n 0) (identical? n 1))
						 1
						(+  (fib (dec n) )  (fib (- n 2)))))
			(prn "fib 36:" (fib 36))

... in the Clojure REPL ...

			cljs.compiler> (time (fib 36))
			"Elapsed time: 1138.814 msecs"
			24157817
			cljs.compiler> (compile-file "bench.cljs")

... in the shell ...

			$ gsc -exe bench.scm
			$ time ./bench
			fib 36: 24157817
			real	0m0.775s
			user	0m0.737s
			sys	0m0.009s