75,176 research outputs found
Total Haskell is Reasonable Coq
We would like to use the Coq proof assistant to mechanically verify
properties of Haskell programs. To that end, we present a tool, named
hs-to-coq, that translates total Haskell programs into Coq programs via a
shallow embedding. We apply our tool in three case studies -- a lawful Monad
instance, "Hutton's razor", and an existing data structure library -- and prove
their correctness. These examples show that this approach is viable: both that
hs-to-coq applies to existing Haskell code, and that the output it produces is
amenable to verification.Comment: 13 pages plus references. Published at CPP'18, In Proceedings of 7th
ACM SIGPLAN International Conference on Certified Programs and Proofs
(CPP'18). ACM, New York, NY, USA, 201
Group Communication Patterns for High Performance Computing in Scala
We developed a Functional object-oriented Parallel framework (FooPar) for
high-level high-performance computing in Scala. Central to this framework are
Distributed Memory Parallel Data structures (DPDs), i.e., collections of data
distributed in a shared nothing system together with parallel operations on
these data. In this paper, we first present FooPar's architecture and the idea
of DPDs and group communications. Then, we show how DPDs can be implemented
elegantly and efficiently in Scala based on the Traversable/Builder pattern,
unifying Functional and Object-Oriented Programming. We prove the correctness
and safety of one communication algorithm and show how specification testing
(via ScalaCheck) can be used to bridge the gap between proof and
implementation. Furthermore, we show that the group communication operations of
FooPar outperform those of the MPJ Express open source MPI-bindings for Java,
both asymptotically and empirically. FooPar has already been shown to be
capable of achieving close-to-optimal performance for dense matrix-matrix
multiplication via JNI. In this article, we present results on a parallel
implementation of the Floyd-Warshall algorithm in FooPar, achieving more than
94 % efficiency compared to the serial version on a cluster using 100 cores for
matrices of dimension 38000 x 38000
Type-Directed Weaving of Aspects for Polymorphically Typed Functional Languages
Incorporating aspect-oriented paradigm to a polymorphically typed functional
language enables the declaration of type-scoped advice, in which the
effect of an aspect can be harnessed by introducing possibly polymorphic
type constraints to the aspect. The amalgamation of aspect orientation and
functional programming enables quick behavioral adaption of functions, clear
separation of concerns and expressive type-directed programming. However,
proper static weaving of aspects in polymorphic languages with a type-erasure
semantics remains a challenge. In this paper, we describe a type-directed
static weaving strategy, as well as its implementation, that supports
static type inference and static weaving of programs written in an aspect-oriented
polymorphically typed functional language, AspectFun. We show
examples of type-scoped advice, identify the challenges faced with compile-time
weaving in the presence of type-scoped advice, and demonstrate how
various advanced aspect features can be handled by our techniques. Lastly,
we prove the correctness of the static weaving strategy with respect to the
operational semantics of AspectFun
Supporting software maintenance with non-functional information
The paper highlights the role of non functional information (about efficiency, reliability and other software attributes) of software components in software maintenance, focusing in the component programming framework. Non functional information is encapsulated in modules bound to both definitions and implementations of software components and it is written as expressions in a classical programming language. It is shown with an example how this notation supports software maintenance, with the help of an algorithm which is able to select the best implementation of a software component in its context of use, meaning byPeer ReviewedPostprint (published version
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