I want to announce that library(ffi) is now available on the master branch of Scryer Prolog. The purpose of this library is be able to call native code via a C ABI. Note that FFI is just one way to communicate with the outside world in Scryer Prolog: sockets, files, pipes or the HTTP libraries are also good options depending on the task and they're safer. This library is based on libffi

Multi-core and highly-connected architectures have become ubiquitous, and this has brought renewed interest in language-based approaches to the exploitation of parallelism. Since its inception, logic programming has been recognized as a programming paradigm with great potential for automated exploitation of parallelism. The comprehensive survey of the first twenty years of research in parallel logic programming, published in 2001, has served since as a fundamental reference to researchers and developers. The contents are quite valid today, but at the same time the field has continued evolving at a fast pace in the years that have followed. Many of these achievements and ongoing research have been driven by the rapid pace of technological innovation, that has led to advances such as very large clusters, the wide diffusion of multi-core processors, the game-changing role of general-purpose graphic processing units, and the ubiquitous adoption of cloud computing. This has been paralleled by significant advances within logic programming, such as tabling, more powerful static analysis and verification, the rapid growth of Answer Set Programming, and in general, more mature implementations and systems. This survey provides a review of the research in parallel logic programming covering the period since 2001, thus providing a natural continuation of the previous survey. The goal of the survey is to serve not only as a reference for researchers and developers of logic programming systems, but also as engaging reading for anyone interested in logic and as a useful source for researchers in parallel systems outside logic programming.
Authors: Agostino Dovier, Andrea Formisano, Gopal Gupta, Manuel V. Hermenegildo, Enrico Pontelli, Ricardo Rocha

Prolog modules are objects. This statement may surprise you. From past experience, it will also annoy some Prolog practitioners. It is not the case that the creators of Prolog module systems intended to create an object-oriented extension to Prolog. But what modules are is a function of their characteristics, not a function of their design.

Logtalk inherits but also extends and improves Prolog predicate semantics to provide clear and uniform closed world semantics, support protocols, provide consistent meta-predicate semantics, prevent misusing of multifile predicates, and prevent a number of hacks based on predicate directives that would break encapsulation. This post discusses...

Prolog programs have both logical and procedural meanings. In this post we'll take a look at procedural ideas more commonly associated with functional programming than Prolog, namely: map, filter and reduce (foldl and foldr). We'll code them and then query them.

In the process of developing a fairly large SWI-Prolog project, I've developed some experience at using PlDoc — which actually goes beyond being an automated documentation system, doubling as an integrated development environment — and PlUnit, which I'll share here.

Announcing my Prolog LSP implementation and discussing how it was implemented