Installation

• Install MIT/GNU Scheme (required)

  sudo aptitude install mit-scheme mit-scheme-doc mit-scheme-dbg
  

  or http://www.gnu.org/software/mit-scheme/

• Install Mechanics Scmutils (optional) http://groups.csail.mit.edu/mac/users/gjs/6946/linux-install.htm

Quick Start

Execute git submodule init to fetch the unit test framework and execute ./run-tests to self-test

Run (load "load") in Scheme to grab everything and start playing with it

core/example-networks.scm and examples/* have usage examples

Main Documentation

• Intellectual foundation

  • Alexey Radul and Gerald Jay Sussman. The Art of the Propagator. CSAIL Tech Report MIT-CSAIL-TR-2009-002, MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA, 2009. http://hdl.handle.net/1721.1/44215

  • Alexey Radul. Propagation Networks: A Flexible and Expressive Substrate for Computation. PhD thesis, Massachusetts Institute of Technology, Cambridge, MA, September 2009. http://hdl.handle.net/1721.1/49525

• Programmer manual: http://groups.csail.mit.edu/mac/users/gjs/propagators/

Content

The doc/ directory contains documents about the whole system, and aspects of it. The main attractions as of this writing are the Propagator Networks thesis and the Art of the Propagator paper.

The core/ directory implements Alexey's thesis, much sanitized and extended and updated.

The extensions/ directory adds (or attempts to add) various additional features and ideas. The rest of the software relies on the extensions in extensions/ as well as the core in core/.

The examples/ directory contains extended examples of uses of propagator networks. This code is not in any sense part of the system, but is a series of clients.

The support/ directory contains supporting stuff that isn't about propagators at all; just useful helpers and langauge facilities.

• eq-properties
• generic operations
• profilers
• miscellaneous utilities

The testing/ directory (submodule) is the unit testing framework this project uses, distributed here in source form. As software, testing/ is a separate entity and not part of the propagator project at all; but it so happens that Alexey also maintains it.

Loading Convention

Loading is done through files called load.scm in every directory. They are responsible for collecting the contents of their own directory, and for loading their needed dependencies when appropriate.

The toplevel load.scm is the main entry point. extensions/load.scm, core/load.scm, and examples/load.scm serve as secondary entry points for those portions of the system.

Unit Testing

run-tests scripts run the unit tests for the portion of system in that directory. The toplevel run-tests runs all the unit tests.

examples/run-examples exercises all the extended examples. This takes a minute, so is not considered part of the normal test suite.

Unit tests are in test/ subdirectories of their respective directories. The test suites are independent of each other, and nothing depends on them.

The unit tests are organized into test groups. Test groups are named after the test files they are in.

Test suites can also be run from the REPL by loading the system, loading an appropriate test suite's test/load.scm file, and running (run-registered-tests). This offers interactive debugging of the tests.

Some of the extensions rely on the symbolic algebra subsystems in Mechanics Scmutils. The full system will load just fine into a normal MIT/GNU Scheme, but extensions that need symbolic algebra will not work. The extensions/run-tests script will not run without a Mechanics install, and the extensions/test/load.scm test suite will fail if you run it from the REPL in MIT/GNU Scheme.

None of this applies to the testing/ directory, since it is a separate software project that happens to be distributed here as a submodule.

License

Copyright 2009-2010 Alexey Radul. This file is part of Propagator Network Prototype.

Propagator Network Prototype is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Propagator Network Prototype is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Propagator Network Prototype. If not, see http://www.gnu.org/licenses/.