Implementation and DCGs

Appeared in Volume 8/1, February 1995

There are two new WWW pages that may be of interest to logic programmers:

1. The talk "Issues in Implementing Logic Languages", is available at http://ps-www.dfki.uni-sb.de/~vanroy/impltalk.html. It is divided into three parts: high-level issues, Prolog implementation issues, and general implementation techniques. Examples are taken from various logic languages, including constraint languages. The talk provides a wealth of information that will be helpful to both the novice implementor and the experienced practitioner.

2. A collection of papers, programs, and preprocessors related to the Extended Definite Clause Grammar notation is available at http://ps-www.dfki.uni-sb.de/~vanroy/edcg.html. Extended DCG's generalize Prolog's Definite Clause Grammar notation to support multiple named accumulators. EDCG's allow effective declarative programming with state. They enforce single-threading for state updating. They keep a program short and make it easier to maintain. With the term_expansion mechanism their use is transparent to the programmer. Extended DCG's are related to the use of monads in functional programming.

For more information, contact:

Peter Van Roy
DFKI Saarbruecken GmbH
D-66123 Saarbruecken, Germany
Email: vanroy@dfki.uni-sb.de