12,012 research outputs found
On the Implementation of GNU Prolog
GNU Prolog is a general-purpose implementation of the Prolog language, which
distinguishes itself from most other systems by being, above all else, a
native-code compiler which produces standalone executables which don't rely on
any byte-code emulator or meta-interpreter. Other aspects which stand out
include the explicit organization of the Prolog system as a multipass compiler,
where intermediate representations are materialized, in Unix compiler
tradition. GNU Prolog also includes an extensible and high-performance finite
domain constraint solver, integrated with the Prolog language but implemented
using independent lower-level mechanisms. This article discusses the main
issues involved in designing and implementing GNU Prolog: requirements, system
organization, performance and portability issues as well as its position with
respect to other Prolog system implementations and the ISO standardization
initiative.Comment: 30 pages, 3 figures, To appear in Theory and Practice of Logic
Programming (TPLP); Keywords: Prolog, logic programming system, GNU, ISO,
WAM, native code compilation, Finite Domain constraint
Timetabling in constraint logic programming
In this paper we describe the timetabling problem and its solvability in a Constraint Logic
Programming Language. A solution to the problem has been developed and implemented in
ECLiPSe, since it deals with finite domains, it has well-defined interfaces between basic
building blocks and supports good debugging facilities. The implemented timetable was
based on the existing, currently used, timetables at the School of Informatics at out
university. It integrates constraints concerning room and period availability
A Denotational Semantics for First-Order Logic
In Apt and Bezem [AB99] (see cs.LO/9811017) we provided a computational
interpretation of first-order formulas over arbitrary interpretations. Here we
complement this work by introducing a denotational semantics for first-order
logic. Additionally, by allowing an assignment of a non-ground term to a
variable we introduce in this framework logical variables.
The semantics combines a number of well-known ideas from the areas of
semantics of imperative programming languages and logic programming. In the
resulting computational view conjunction corresponds to sequential composition,
disjunction to ``don't know'' nondeterminism, existential quantification to
declaration of a local variable, and negation to the ``negation as finite
failure'' rule. The soundness result shows correctness of the semantics with
respect to the notion of truth. The proof resembles in some aspects the proof
of the soundness of the SLDNF-resolution.Comment: 17 pages. Invited talk at the Computational Logic Conference (CL
2000). To appear in Springer-Verlag Lecture Notes in Computer Scienc
An overview of the ciao multiparadigm language and program development environment and its design philosophy
We describe some of the novel aspects and motivations behind
the design and implementation of the Ciao multiparadigm programming system. An important aspect of Ciao is that it provides the programmer with a large number of useful features from different programming paradigms and styles, and that the use of each of these features can be turned on and off at will for each program module. Thus, a given module may be using e.g. higher order functions and constraints, while another module may be using objects, predicates, and concurrency. Furthermore, the language is designed to be extensible in a simple and modular way. Another important aspect of Ciao is its programming environment, which provides a powerful preprocessor (with an associated assertion language) capable of statically finding non-trivial bugs, verifying that programs comply with specifications, and performing many types of program optimizations. Such optimizations produce code that is highly competitive with other dynamic languages or, when the highest levéis of optimization are used, even that of static languages, all while retaining the interactive development environment of a dynamic language. The environment also includes a powerful auto-documenter. The paper provides an informal overview of the language and program development environment. It aims at illustrating the design philosophy rather than at being exhaustive, which would be impossible in the format of a paper, pointing instead to the existing literature on the system
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Silicon compilation
Silicon compilation is a term used for many different purposes. In this paper we define silicon compilation as a mapping from some higher level description into layout. We define the basic issues in structural and behavioral silicon compilation and some possible solutions to those issues. Finally, we define the concept of an intelligent silicon compiler in which the compiler evaluates the quality of the generated design and attempts to improve it if it is not satisfactory
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