Difference lists in Prolog

How to Teach Difference Lists?

Lists are, on the one hand, a useful modeling construct in logic programming because of their not predefined length, on the other hand the concatenation of lists by append(L1,L2,L3) is rather inefficient because it copies the list L1. To avoid the invocation of the append/3-procedure an alternative possibility is the use of incomplete lists of the form [ el1, ... elk | Var], in which Var descri...

When stopword lists make the difference

In this brief communication, we evaluate the use of two stopword lists for the English language (one comprising 571 words and another with 9) and compare them with a search approach accounting for all word forms. We show that through implementing the original Okapi form or certain ones derived from the Divergence from Randomness (DFR) paradigm, significantly lower performance levelsmay result w...

Improving Functional Logic Programs by Difference-Lists

Modern multi-paradigm declarative languages integrate features from functional, logic, and concurrent programming. In this work, we consider the adaptation of the logic programming transformation based on the introduction of diierence-lists to an integrated setting. Unfortunately, the use of diierence-lists is impractical due to the absence of non-strict equality in lazy (call-by-name) language...

GNU Prolog: Beyond Compiling Prolog to C

We describe in this paper the compilation scheme of the GNU Prolog system. This system is built on our previous experience of compiling Prolog to C in wamcc. The compilation scheme has been however redesigned to overcome drawbacks of the compilation to C. In particular, GNU-Prolog is based on a low-level miniassembly platform-independent language that makes it possible to avoid the phase of com...

GNU Prolog: beyond ompiling Prolog to C