A Coq-based synthesis of Scala programs which are correct-by-construction

The present paper introduces Scala-of-Coq, a new compiler that allows a Coq-based synthesis of Scala programs which are "correct-by-construction". A typical workflow features a user implementing a Coq functional program, proving this program's correctness with regards to its specification and making use of Scala-of-Coq to synthesize a Scala program that can seamlessly be integrated into an existing industrial Scala or Java application.Comment: 2 pages, accepted version of the paper as submitted to FTfJP 2017 (Formal Techniques for Java-like Programs), June 18-23, 2017, Barcelona , Spai

Processing of ICARTT Data Files Using Fuzzy Matching and Parser Combinators

In this paper, the task of parsing and matching inconsistent, poorly formed text data through the use of parser combinators and fuzzy matching is discussed. An object-oriented implementation of the parser combinator technique is used to allow for a relatively simple interface for adapting base parsers. For matching tasks, a fuzzy matching algorithm with Levenshtein distance calculations is implemented to match string pair, which are otherwise difficult to match due to the aforementioned irregularities and errors in one or both pair members. Used in concert, the two techniques allow parsing and matching operations to be performed which had previously only been done manually

Haiku - a Scala combinator toolkit for semi-automated composition of metaheuristics

There is an emerging trend towards the automated design of metaheuristics at the software component level. In principle, metaheuristics have a relatively clean decomposition, where well-known frameworks such as ILS and EA are parametrised by variant components for acceptance, perturbation etc. Automated generation of these frameworks is not so simple in practice, since the coupling between components may be implementation specific. Compositionality is the ability to freely express a space of designs ‘bottom up’ in terms of elementary components: previous work in this area has used combinators, a modular and functional approach to componentisation arising from foundational Computer Science. In this article, we describeHaiku, a combinator tool-kit written in the Scala language, which builds upon previous work to further automate the process by automatically composing the external dependencies of components. We provide examples of use and give a case study in which a programatically-generated heuristic is applied to the Travelling Salesman Problem within an Evolutionary Strategies framework

Polymonadic Programming

Monads are a popular tool for the working functional programmer to structure effectful computations. This paper presents polymonads, a generalization of monads. Polymonads give the familiar monadic bind the more general type forall a,b. L a -> (a -> M b) -> N b, to compose computations with three different kinds of effects, rather than just one. Polymonads subsume monads and parameterized monads, and can express other constructions, including precise type-and-effect systems and information flow tracking; more generally, polymonads correspond to Tate's productoid semantic model. We show how to equip a core language (called lambda-PM) with syntactic support for programming with polymonads. Type inference and elaboration in lambda-PM allows programmers to write polymonadic code directly in an ML-like syntax--our algorithms compute principal types and produce elaborated programs wherein the binds appear explicitly. Furthermore, we prove that the elaboration is coherent: no matter which (type-correct) binds are chosen, the elaborated program's semantics will be the same. Pleasingly, the inferred types are easy to read: the polymonad laws justify (sometimes dramatic) simplifications, but with no effect on a type's generality.Comment: In Proceedings MSFP 2014, arXiv:1406.153

Controlling Contractors with Monads for Hybrid Dynamical Systems

Physical systems with intelligent behaviors result from inter-actions of different fields: sensor networks, robotics, optimization, reasoning, etc. Rooted in this philosophy of interdisciplinary, this paper makes a connexion between hybrid dynamical systems, interval-based constraint propagation and functional programming. It shows how to build a monadic program in Haskell to control contractors (constraint propagators) for the state estimation of multi-model (hy- brid) dynamical systems, subject to partial and uncertain measurements. The example of system taken here is an elevator that can either be moving upward, downward or stopped. The altitude is measured directly and the estimation problem is simply to track its motion. The purpose of the Haskell library is to offer both a high-level and flexible framework for building propagation strategies based on user knowledge or user requirements.L'élaboration de sytèmes autonomes est le résultat d'interactions entre différents domaines: réseau de capteurs, robotique, optimisation, raison- nement automatique, etc. Cet article, ancré dans cette philosophie pluridis- ciplinaire, montre une connexion entre les systèmes hybrides dynamiques, la propagation de contraintes sur intervalles et la programmation fonctionnelle. Plus précisément, il montre comment concevoir un programme monadique en Haskell pour contrôler les contracteurs (propagateurs de contraintes) permet- tant l'estimation d'état de systèmes dynamiques multi-modéles (hybrides), su- jets à des mesures partielles et incertaines. L'exemple de système pris ici est un ascenseur qui peut monter, descendre ou être stopé. L'altitude est mesurée directement et le problème d'estimation est simplement de suivre son mouve- ment. L'objectif de la bibliothéque Haskell est d'offrir un cadre à la fois flexible et de haut niveau pour construire des stratégies de propagation basées sur les connaissances ou les pré-requis de l'utilisateur

Shortcut fusion rules for the derivation of circular and higher-order monadic programs

Functional programs often combine separate parts using intermediate data structures for communicating results. Programs so defined are modular, easier to understand and maintain, but suffer from inefficiencies due to the generation of those gluing data structures. To eliminate such redundant data structures, some program transformation techniques have been proposed. One such technique is shortcut fusion, and has been studied in the context of both pure and monadic functional programs. In this paper, we study several shortcut fusion extensions, so that, alternatively, circular or higher-order programs are derived. These extensions are also provided for effect-free programs and monadic ones. Our work results in a set of generic calculation rules, that are widely applicable, and whose correctness is formally established.(undefined

Lazy functional parser combinators in Java

A parser is a program that checks if a text is a sentence of the language as described by a grammar. Traditionally, the program text of a parser is generated from a grammar description, after which it is compiled and subsequently run. The language accepted by such a parser is, by the nature of this process, hardcoded in the program. Another approach, primarily taken in the context of functional languages, allows parsers to be constructed at runtime, thus dynamically creating parsers by combining elements from libraries of higher level parsing concepts; this explanins the the name "parser combinators". Efficient implementation of this concept relies heavily on the laziness that is available in modern functional languages [13, 14]. This paper shows how to use parser combinators in a functional language as well as Java, and shows how parser combinators can be implemented in Java. Implementing parser combinators is accomplished by combining two libraries. The first one, written in Haskell, defines error-correcting and analysing parser combinators [2]. The second one consists of a small Java library implementing lazy functional behavior. The combinator library is straightforwardly coded in Java, using lazy behavior where necessary. In this paper all three aspects, the two libraries and its combination, are explained