A Java Interface to Prolog
March 18, 2003
May 5, 1999
See the Copyright and
License Information section for more information.
- JPL 1.0.1 released. This release contains the following changes:
- Fixed a bug with the representation of Tuples. They are now
always binary terms, though generally structured as binary
trees. The interface is the same, except we now require that Tuples
contain at least two elements. (The single element constructor
has been removed, but I consider this a patch, not an interface change)
- Added an ith() accessor to the Compound and Query classes. This is
used to obtain the ith element in the array of Terms in the Compound or Query.
- Added a debugString() method to the Term and Query classes.
This is used to obtain more detailed information about the structure of the
Term or Query.
- Updated and fixed some of the documentation.
- JPL is now released under the terms of the Gnu Library Public License,
not the Gnu General Public License. All relevant files have been updated.
Feb 25, 1999
- JPL 1.0.0 is out. Check the download
section for information about how to retrieve it. I hope most
of the core interfaces are frozen.
- I am in need of Solaris testers! I have access to a Solaris
box, but it has ancient and outdated compilers, libs, etc. If anyone
gets this to compile on any platform other than Linux, please send me patches.
- Eventually I'd like to work out some config scripts. For now
you must config manually. Sorry.
- I have not even tried getting this to run under Windows. Anyone
with more expertise (and patience) than I is welcome to give it a go!
JPL is a set of Java classes and C functions providing an interface between
Java and Prolog. JPL uses the Java Native Interface (JNI) to connect
to a Prolog engine through the Prolog Foreign Language Interface (FLI),
which is more or less in the process of being standardized in various implementations
of Prolog. JPL is not a pure Java implementation of Prolog; it makes
extensive use of native implementations of Prolog on supported platforms.
The current version of JPL only works with SWI-Prolog.
Currently, JPL only supports the embedding of a Prolog engine within the
Java VM. Future versions may support the embedding of a Java VM within
Prolog, so that, for example, one could take advantage of the rich class structure
of the Java environment from within Prolog.
JPL is designed in two layers, a low-level interface to the Prolog FLI
and a high-level Java interface for the Java programmer who is not concerned
with the details of the Prolog FLI. The low-level interface is provided
for C programmers who may wish to port their C implementations which use
the FLI to Java with minimal fuss.
JPL now requires SWI-Prolog version 3.1.0 or later, which is available
at the following URL:
SWI-Prolog license information is available here:
You will also need a Java development environment. Sun's Java website
is a good place to start:
JPL 2.0.2 was developed and tested on Windows NT4, and has not yet been compiled
on any non-Windows platform
JPL1.0.1 was written and tested on Linux kernel 2.1.24. It should compile
on any other UNIX system with a full suite of gnu tools.
Copyright and License
JPL is released under the terms of the Gnu Library Public License:
Copyright (c) 2003 Paul Singleton. All rights reserved.
This means, among other things, that you may use this software in
commercial products without being required to distribute your software under
the same licensing terms. See the License for
Copyright (c) 1998 Fred Dushin. All rights reserved.
This library is free software; you can redistribute
it and/or modify it under the terms of the GNU Library Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
This library 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 Library
Public License for more details.
The Documentation for JPL is organized into the following sections:
- Getting Started
- The Low-Level Interface
- The High-Level Interface
- Gnu Public License
- The JPL API
Download (this section is obsolete)
Gnu-zipped, UNIX compressed, and Zipped versions of the source distribution
are available at:
You may be interested in viewing the ChangeLog.
The latest version of JPL is available by the World Wide Web at the following
Writing free software is only gratifying if you hear from users.
Please feel free to contact the author, Fred Dushin, at the following address:
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JPL logo was made by the Gimp.