173,110 research outputs found
Optimizing Abstract Abstract Machines
The technique of abstracting abstract machines (AAM) provides a systematic
approach for deriving computable approximations of evaluators that are easily
proved sound. This article contributes a complementary step-by-step process for
subsequently going from a naive analyzer derived under the AAM approach, to an
efficient and correct implementation. The end result of the process is a two to
three order-of-magnitude improvement over the systematically derived analyzer,
making it competitive with hand-optimized implementations that compute
fundamentally less precise results.Comment: Proceedings of the International Conference on Functional Programming
2013 (ICFP 2013). Boston, Massachusetts. September, 201
Holographic and 3D teleconferencing and visualization: implications for terabit networked applications
Abstract not available
Grammatical metaphors in English
This article focuses on the concept of 'grammatical metaphor' as it has been introduced in the framework of Systemic Functional Linguistics. It first explains 'metaphor' in general, as it is traditionally known. In contrast to this, grammatical metaphor is explained as a grammatical resource in language. Two types of grammatical metaphor, ideational metaphor and interpersonal metaphor, are explained and illustrated
Matrix Code
Matrix Code gives imperative programming a mathematical semantics and
heuristic power comparable in quality to functional and logic programming. A
program in Matrix Code is developed incrementally from a specification in
pre/post-condition form. The computations of a code matrix are characterized by
powers of the matrix when it is interpreted as a transformation in a space of
vectors of logical conditions. Correctness of a code matrix is expressed in
terms of a fixpoint of the transformation. The abstract machine for Matrix Code
is the dual-state machine, which we present as a variant of the classical
finite-state machine.Comment: 39 pages, 19 figures; extensions and minor correction
A Programming Language for Web Service Development
There is now widespread acceptance of Web services and service-oriented architectures. But despite the agreement on key Web services standards there remain many challenges. Programming environments based on WSDL support go some way to facilitating Web service development. However Web services fundamentally rely on XML and Schema, not on contemporary programming language type systems such as those of Java or .NET. Moreover, Web services are based on a messaging paradigm and hence bring forward the traditional problems of messaging systems including concurrency control and message correlation. It is easy to write simple synchronous Web services using traditional programming languages; however more realistic scenarios are surprisingly difficult to implement. To alleviate these issues we propose a programming language which directly supports Web service development. The language leverages XQuery for native XML processing, supports implicit message correlation and has high level join calculus-style concurrency control. We illustrate the features of the language through a motivating example
Fine-grained visualization pipelines and lazy functional languages
The pipeline model in visualization has evolved from a conceptual model of data processing into a widely used architecture for implementing visualization systems. In the process, a number of capabilities have been introduced, including streaming of data in chunks, distributed pipelines, and demand-driven processing. Visualization systems have invariably built on stateful programming technologies, and these capabilities have had to be implemented explicitly within the lower layers of a complex hierarchy of services. The good news for developers is that applications built on top of this hierarchy can access these capabilities without concern for how they are implemented. The bad news is that by freezing capabilities into low-level services expressive power and flexibility is lost. In this paper we express visualization systems in a programming language that more naturally supports this kind of processing model. Lazy functional languages support fine-grained demand-driven processing, a natural form of streaming, and pipeline-like function composition for assembling applications. The technology thus appears well suited to visualization applications. Using surface extraction algorithms as illustrative examples, and the lazy functional language Haskell, we argue the benefits of clear and concise expression combined with fine-grained, demand-driven computation. Just as visualization provides insight into data, functional abstraction provides new insight into visualization
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