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Copyright 2009-2010 Alexey Radul.
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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/>.
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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 ./run-tests in a shell 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


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
  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 in source form.