cowbel / README

                                 COWBEL V0.2

                              © 2012 David Given


cowbel is a minimalist but expressive statically typed programming language
which compiles into real machine code via C. It has generics, interfaces, a
garbage collector, non-nullable types, an object-oriented system based on
interfaces and composition, and features a familiar Javascript-like syntax.

The purpose of cowbel is to fit the niche where hard-core systems languages
like C or C++ are too much work, but dynamic or virtual-machine languages
like Python or Java are too heavyweight. cowbel programs compile into
standalone executables with few dependencies that have comparable size and
performance to C.


In order to use cowbel, currently you need:

 - a Unixish. There is nothing platform-specific in cowbel, but I wrote it on
   Linux and that's what everything assumes. If you want it to work on
   anything else you'll need to hack it.
 - Java 6 or above with the following Apache Commons modules:
 - The Boehm garbage collector:
 - Ant 1.8.
 - gcc.
If you have Debian, you've already got all these. Merely install these

  libgc-dev libcommons-io-java libcommons-lang3-java libcommons-cli-java

Once this is all set up, build it with this:

Assuming this works, you can now invoke cowbel with the 'cowbel' shell script.

  ./cowbel -Iinclude test/life.cow -o life
This should produce an executable called 'life' which you can run.

If it *didn't* work, most likely you'll need to edit the Java classpath
because things on your system don't match mine. The classpath is stored in
'build.xml' and 'cowbel' and should be trivial to modify.

It's probably also a good idea to run the test suite, just to make sure
everything works:


You can find some slightly less trivial sample programs in the 'samples'
directory. (Feel like submitting some? Let me know!)


Cowbel is a programming language, and as such the manual is beyond the scope
of this README. Please see the cowbel web site for more information:
If you use cowbel, please join the mailing list. This will allow you
to ask questions, hopefully receive answers, and get news about any
new releases. You can subscribe or view the archives at the following page:

For reference, the distribution you're looking at right now contains:

  src/        the Java source code to the cowbel compiler
  build.xml   the antfile that builds the compiler
  cowbel      a shell script that runs the compiler
  include/    the cowbel standard library
  test/       the test suite and example code
  run-tests   a shell script that runs the test suite


There's a whole bunch of stuff missing in cowbel. Most notably:

 - complete type checking (some invalid programs will be accepted)
 - dataflow analysis (undefined variables and missing return arguments are
   not detected)
 - complete coverage of primitive data types (strings only support three
   methods, for example)
 - object composition
 - interface inheritance
If you find anything else wrong, feel free to file a bug here:

I like bug reports. I like them even better if they have a minimal test case


Most of cowbel is available under the two-clause BSD license. Please see the
COPYING.BSD file for the full text.

Portions of cowbel, including the test suite and the runtime library, are
Creative Commons Zero distributable. Please see the COPYING.CC0 file for more


Cowbel 0.2: 2012-03-20: Rewrote most of the compiler core to be much more
orthogonal, consistent, flexible, etc. Now uses global type inference to
determine the concrete type of values. Much, *much* better code produced as
a result. Lots of bugfixes, rearrangements, improvements, etc.

Cowbel 0.1: 2012-02-13: Initial release.


Cowbel was written by me, David Given. You may contact me at,
or visit my website at There may or may not be
anything interesting there.