Wild_LIFE

Appeared in Volume 6/1, February 1993

The Wild_LIFE interpreter is the first implementation of the LIFE language available to the general public. It is a product of the Paradise project at the DEC Paris Research Laboratory.

LIFE (Logic, Inheritance, Functions, and Equations) is an experimental programming language with a powerful facility for structured type inheritance. It reconciles styles from functional programming, LP and OOP. It subsumes, and fully contains the functionality of, the precursor languages LOGIN and Le_Fun. The syntax of Wild_LIFE has been kept as close as possible to that of the Edinburgh family of Prolog so that Prolog compatibility is easy to achieve.

From a theoretical point of view, LIFE implements a constraint LP language with equality (unification) and entailment (matching) constraints over order-sorted feature terms. The interplay of unification and matching provides an implicit coroutining facility thanks to an automatic suspension mechanism. This allows interleaving interpretation of relational and functional expressions which specify structural dependencies on objects.

The Wild_LIFE interpreter is a fully functional implementation of the LIFE language. It has been extensively tested on DECstations running Ultrix, and it should not be hard to port to other Unix workstations. It has a comfortable user interface with incremental query extension ability. It contains an extensive set of built-in operations as well as an X Windows interface.

This release contains the following:

1. The C and LIFE source code of Wild_LIFE.

2. A set of non-trivial example programs including an incremental Gaussian equation solver, a PERT scheduler, a full LIFE parser, a flower-drawing program that handles X events, uses an X toolkit and a 3D turtlegraphics package written in LIFE and compiles rewrite rules into LIFE.

3. A draft user manual.

4. An extensive test suite to verify the correct working of the interpreter.

Uncompress and untar this file to obtain the Life/ directory. Read Life/README for further instructions.

The Paradise project has written many articles and research reports on various aspects of LIFE. Read Life/README for instructions on how to get copies.

Relevant electronic mail addresses:

life-users@prl.dec.com
This is a mailing list of people using LIFE or interested in specific aspects of LIFE, whether theory, implementation, or applications.

life-request@prl.dec.com
Send messages to this address to be put on, or removed from, the life-users mailing list.

life-bugs@prl.dec.com

paradise@prl.dec.com
This is PRL's local LIFE community.