5,162 research outputs found
Semantic Component Composition
Building complex software systems necessitates the use of component-based
architectures. In theory, of the set of components needed for a design, only
some small portion of them are "custom"; the rest are reused or refactored
existing pieces of software. Unfortunately, this is an idealized situation.
Just because two components should work together does not mean that they will
work together.
The "glue" that holds components together is not just technology. The
contracts that bind complex systems together implicitly define more than their
explicit type. These "conceptual contracts" describe essential aspects of
extra-system semantics: e.g., object models, type systems, data representation,
interface action semantics, legal and contractual obligations, and more.
Designers and developers spend inordinate amounts of time technologically
duct-taping systems to fulfill these conceptual contracts because system-wide
semantics have not been rigorously characterized or codified. This paper
describes a formal characterization of the problem and discusses an initial
implementation of the resulting theoretical system.Comment: 9 pages, submitted to GCSE/SAIG '0
Trustworthy Refactoring via Decomposition and Schemes: A Complex Case Study
Widely used complex code refactoring tools lack a solid reasoning about the
correctness of the transformations they implement, whilst interest in proven
correct refactoring is ever increasing as only formal verification can provide
true confidence in applying tool-automated refactoring to industrial-scale
code. By using our strategic rewriting based refactoring specification
language, we present the decomposition of a complex transformation into smaller
steps that can be expressed as instances of refactoring schemes, then we
demonstrate the semi-automatic formal verification of the components based on a
theoretical understanding of the semantics of the programming language. The
extensible and verifiable refactoring definitions can be executed in our
interpreter built on top of a static analyser framework.Comment: In Proceedings VPT 2017, arXiv:1708.0688
Process Algebras
Process Algebras are mathematically rigorous languages with well defined semantics that permit describing and verifying properties of concurrent communicating systems.
They can be seen as models of processes, regarded as agents that act and interact continuously with other similar agents and with their common environment. The agents may be real-world objects (even people), or they may be artifacts, embodied perhaps in computer hardware or software systems.
Many different approaches (operational, denotational, algebraic) are taken for describing the meaning of processes. However, the operational approach is the reference one. By relying on the so called Structural Operational Semantics (SOS), labelled transition systems are built and composed by using the different operators of the many different process algebras. Behavioral equivalences are used to abstract from unwanted details and identify those systems that react similarly to external
experiments
Efficient Normal-Form Parsing for Combinatory Categorial Grammar
Under categorial grammars that have powerful rules like composition, a simple
n-word sentence can have exponentially many parses. Generating all parses is
inefficient and obscures whatever true semantic ambiguities are in the input.
This paper addresses the problem for a fairly general form of Combinatory
Categorial Grammar, by means of an efficient, correct, and easy to implement
normal-form parsing technique. The parser is proved to find exactly one parse
in each semantic equivalence class of allowable parses; that is, spurious
ambiguity (as carefully defined) is shown to be both safely and completely
eliminated.Comment: 8 pages, LaTeX packaged with three .sty files, also uses cgloss4e.st
Carnap: an Open Framework for Formal Reasoning in the Browser
This paper presents an overview of Carnap, a free and open framework for the development of formal reasoning applications. Carnapās design emphasizes flexibility, extensibility, and rapid prototyping. Carnap-based applications are written in Haskell, but can be compiled to JavaScript to run in standard web browsers. This combination of features makes Carnap ideally suited for educational applications, where ease-of-use is crucial for students and adaptability to different teaching strategies and classroom needs is crucial for instructors. The paper describes Carnapās implementation, along with its current and projected pedagogical applications
Action semantics in retrospect
This paper is a themed account of the action semantics project, which Peter Mosses has led since the 1980s. It explains his motivations for developing action semantics, the inspirations behind its design, and the foundations of action semantics based on unified algebras. It goes on to outline some applications of action semantics to describe real programming languages, and some efforts to implement programming languages using action semantics directed compiler generation. It concludes by outlining more recent developments and reflecting on the success of the action semantics project
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