We study an extension of the Hindley/Milner system with explicit type scheme annotations and declarations. The can express polymorphic function arguments, user-defined data types abstract components, structure fields. More generally, all programs lambda calculus be encoded by a translation between typing derivations. show that reconstruction in this reduced to decidable problem first-order unification under mixed prefix.

Many statically typed programming languages provide an abstract data type construct, such as the module in Modula-2. However, most of these languages, implementations types are not first-class values. Thus, they cannot be assigned to variables, passed function parameters, or returned results. Several higher-order functional feature strong and static systems, parametric polymorphism, algebraic types, explicit variables. Most them rely on Hindley-Milner inference instead requiring declarations...

In Java, an interface specifies public abstract methods and associated constants. Conformance of a class to is by name. We propose allow structural conformance interfaces: any or that declares implements each method in target conforms structurally the interface, expression source type can be used where value expected. argue results major gain flexibility situations require retroactive abstraction over types. Structural requires no additional syntax only small modifications Java compiler...

Abstract We argue that the novel combination of type classes and existential types in a single language yields significant expressive power. explore this context higher-order functional languages with static typing, parametric polymorphism, algebraic data Hindley–Milner inference. Adding to an existing already features requires only minor syntactic extension. first demonstrate how provide quantification over by extending syntax definitions, give examples possible uses. then develop system...

Virtualization lets you carve your computer into slices, allowing for great experimentation with different operating systems, tools, and techniques.

Did you ever wish you'd made a backup copy of file before changing it? Or applying collaborator's modifications? Version control systems make this easier, and do lot more.

We describe Triveni, a framework and API for integrating threads events. The design of Triveni is based on an algebra, including preemption combinators, processes. compatible with existing standards, such as Pthreads Java threads, the event models structured Observer pattern. software architecture algorithms underlying concrete implementation in Java. This environment includes specification testing safety properties. results described paper have been used to integrate process-algebraic...

This paper looks at Plone, one of the best content management systems. Plone is distributed under a free open-source license: cost getting started only limited to time you have available set up software on server. written in Python and uses Zope application server infrastructure; it runs most modern operating can be customized for maintenance - entirely over Web.

Since the mid-nineties, server-based Web applications have emerged as a convenient way to provide functionality user audience without any specific software or system requirements except need for reasonably up-to-date browser. The tricky integration, installation, and configuration tasks are under control of an expert on server side. These advantages apply both general public small research teams. Typical browser-based interfaces one more roles might keep some information in persistent...

Testing is an important part of application development hardware engineers, in particular, have a long established history testing for the obvious reason that it's awfully hard to rebuild microprocessor every time bug pops up design stage-not mention enormous headaches such bugs generate on software side. In this installment Scientific Programming, we'll discuss role process and examine ways leverage automated unit your projects

Constraint-based languages can express in a concise way the complex logic of new generation interactive services for applications such as banking or stock trading, that must support multiple types interfaces accessing same data. These include automatic speech-recognition where inputs may be provided any order by users service. We study this paper how to systematically test event-driven developed using languages. show tested automatically, without need manually-written cases, and efficiently,...

There is an emerging consensus in the scientific software community that progress research dependent on "quality and accessibility of at all levels" (wssspe.researchcomputing.org.uk/). This depends embracing best traditional---and emergent---practices engineering, especially agile practices intersect with more formal tradition engineering. As a first step our larger exploratory project to study in-process quality metrics for development projects Computational Science Engineering (CSE), we...

Academic courses focused on individual microcomputers or client/server applications are no longer sufficient for students to develop knowledge in embedded systems. Current and near-term industrial systems employ multiple interacting components new network security approaches; hence, academic preparation requires teaching realistic projects comparable these real-world products. However, the complexity, breadth, technical variations of products difficult reproduce classroom. This paper...

By incorporating automated component, integration, and acceptance testing into the various tiers of a lightweight lava 2 Enterprise Edition (J2EE) Web application architecture, developers can shorten development cycle increase quality their work

Background: In this paper, we present our initial efforts to integrate formal methods, with a focus on model-checking specifications written in Temporal Logic of Actions (TLA+), into computer science education, targeting undergraduate juniors/seniors and graduate students. Formal methods can play key role ensuring correct behavior safety-critical systems, yet remain underutilized educational industry contexts. Aims: We aim (1) qualitatively assess the state programs, (2) construct...

Energy-efficient software helps improve mobile device experiences and reduce the carbon footprint of data centers. However, energy goals are often de-prioritized in order to meet other requirements. We take inspiration from recent work exploring use large language models (LLMs) for different engineering activities. propose a novel application LLMs: as code optimizers efficiency. describe evaluate prototype, finding that over 6 small programs our system can efficiency 3 them, up 2x better...

Computing systems are consuming an increasing and unsustainable fraction of society's energy footprint, notably in data centers. Meanwhile, energy-efficient software engineering techniques often absent from undergraduate curricula. We propose to develop a learning module for software, suitable incorporation into class. There is one major problem with such endeavor: curricula have limited space mastering energy-related programming aspects. To address this problem, we leverage the domain...

We present a novel form of intra-volume directory layering with hierarchical, inheritance-like namespace unification. While each layer an OLFS volume constitutes subvolume that can be mounted separately in fan-in configuration, the entire hierarchy is always accessible (online) and fully navigable through any layer. uses relational database to store its metadata either or (virtual) host file system as backing store, along block caching for improved performance. Because runs virtual...