Ribbit

A small and portable Scheme implementation that supports closures, tail calls, first-class continuations, a REPL and AOT and incremental compilers. All that for a run time footprint around 4 KB!

You can try the REPL with a minimal library here or try a more featureful version here.

Please note that currently the incremental compiler used by the REPL only supports a subset of the Scheme special forms. In particular procedure definitions should use the syntax (define name (lambda ...)) .

Usage

The Ribbit compiler is written in Scheme and can be executed with Gambit, Guile or Chicken. It has been tested with Gambit v4.7.5 and above. For the best experience install Gambit from https://github.com/gambit/gambit .

Currently Ribbit supports the target languages C, JavaScript, Python and Scheme which are selectable with the compiler's -t option with c, js, py, and scm respectively. The compacted RVM code can be obtained with the target none which is the default.

The -m option causes a minification of the generated program. This requires a recent version of Gambit.

The -l option allows selecting the Scheme runtime library (located in the lib subdirectory). The min library has the fewest procedures and a REPL that supports the core Scheme forms only. The max library has most of the R4RS predefined procedures, except for file I/O. The max-tc library is like max but with run time type checking. The default is the max-tc library.

Here are a few examples:

Use Gambit to compile the minimal REPL to JavaScript
and execute with nodejs:

  % cd src
  % gsi rsc.scm -t js -l min repl-min.scm
  % echo "(define f (lambda (n) (if (< n 2) n (+ (f (- n 1)) (f (- n 2))))))(f 25)" | node repl-min.scm.js
  > 0
  > 75025
  > 

Do the same but with Python:

  % cd src
  % gsi rsc.scm -t py -l min repl-min.scm
  % echo "(define f (lambda (n) (if (< n 2) n (+ (f (- n 1)) (f (- n 2))))))(f 25)" | python3 repl-min.scm.py
  > 0
  > 75025
  > 

Use Guile to compile the REPL with type checking to C
and then compile RVM with gcc:

  % cd src
  % guile -s rsc.scm -t c -l max-tc repl-max.scm
  % gcc repl-max.scm.c
  % echo "(+ 1 (* 2 3))(car 0)" | ./a.out
  > 7
  > *** type error
  > 

Use Chicken to compile the minimal REPL to minified Scheme
and execute with Gambit:

  % cd src
  % csi -q rsc.scm -t scm -l min -m repl-min.scm
  % echo "(define twice (lambda (x) (* x 2)))(twice 21)" | gsi repl-min.scm.scm
  > 0
  > 42
  >