Directing JavaScript with arrows

We propose weakening the definition of progress to a branching-time operator, making it more amenable to compositional proof and simplifying the predicates needed to reason about highly asynchronous programs. The new progress operator (“achieves”) coincides with the “leads-to” operator on all “observable” progress properties (those where the target predicate is stable) and satisfies the same composition properties as leads-to, including the PSP theorem. The advantage of achievement lies in its compositionality: a program inherits all achievement properties of its “decoupled components”. (For example, a dataflow network inherits achievement properties from each of its processes.) The compositionality of achievement captures, in a UNITY-like logic, the well-known operational trick of reasoning about an asynchronous program by considering only certain well-behaved executions.KeywordsComposition PropertyProgress PropertyFIFO ChannelTarget PredicateCompositional ProofThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

What's does a mouse drag event have in common with an Array of numbers?

An asynchronous message-passing program P is nondeterministic. Given the same input, multiple executions of P may exercise different send/receive event sequences (or SR-sequences) and may even produce different results. Such nondeterminacy makes it difficult to determine the correctness of P. Let X be an input of P. Assume that any execution of P with X terminates. Reachability testing of P with X is to execute, in a systematic manner, all possible SR-sequences of P with X such that the correctness of P with X can be determined. The basic idea of reachability testing is described as follows. We first execute P with X nondeterministically to collect one or more SR-sequences. For each collected SR-sequence, we analyze its race conditions and generate race variants, which are prefixes of other SR-sequences. We replay race variants to generate new SR-sequences. For each new SR-sequence, we repeat the same process until we eventually execute all possible SR-sequences of P with X. We describe an efficient implementation of reachability testing of asynchronous message-passing programs. Our technique deals with partially-ordered SR-sequences and reduces the complexity and redundancy caused by totally-ordered SR-sequences.

Asynchronous programming is a standard approach for designing responsive applications. Modern languages such as C# provide async/await primitives for the disciplined use of asynchrony. In spite of this, programs can deadlock because of incorrect use of blocking operations along with non-blocking (asynchronous) operations. While developers are aware of this problem, there is no automated technique to detect deadlocks in asynchronous programs.

Asynchronous programming is a standard approach for designing responsive applications. Modern languages such as C# provide async/await primitives for the disciplined use of asynchrony. In spite of this, programs can deadlock because of incorrect use of blocking operations along with non-blocking (asynchronous) operations. While developers are aware of this problem, there is no automated technique to detect deadlocks in asynchronous programs. We present a novel representation of control flow and scheduling of asynchronous programs, called continuation scheduling graph and formulate necessary conditions for a deadlock to occur in a program. We design static analyses to construct continuation scheduling graphs of asynchronous C# programs and to identify deadlocks in them. We have implemented the static analyses in a tool called DeadWait. Using DeadWait, we found 43 previously unknown deadlocks in 11 asynchronous C# libraries. We reported the deadlocks to the library developers. They have confirmed and fixed 40 of them.

Web application development from simple web pages to complex interactive platforms (including social networks, e-commerce systems, corporate portals) requires new approaches, tools and technologies. JavaScript libraries and frameworks play a special role in developing web applications, simplifying the creation of effective, scalable, and convenient interfaces. The purpose of the article is to research the problems and prospects of using React in combination with Redux when creating web applications with a complex structure, to assess the advantages of their joint use in comparison with similar tools and to develop the web application “FarmerProducts”. The research methodology consists of the main methodological approaches and technological tools for developing web applications. Such methods, in particular, are: system and comparative analysis – to identify the features of creating web applications; method of expert assessments, which involves the study of literary sources and information resources, conducting interviews and surveys of experts, as well as the processes of developing and testing scalable and high-performance web applications based on the use of React and Redux. The scientific novelty of the research is the analysis of modern tools (React, Angular, Vue. js) for developing web applications, identifying problems and prospects for their use, creating an author’s web application (using React and Redux), which includes an intuitive interface, a flexible database, simplifying the process of working with the application by using a stack of modern technologies. Conclusions. The paper analyses the problems and prospects of using modern web application development tools; focuses on React, which is suitable for different projects; conducts a comparative analysis of React with Angular, Vue. js and Svelte, identifies their main characteristics, advantages, disadvantages; demonstrates the dependence of the choice of tools on the project context (React in combination with Redux can provide an optimal balance between performance, flexibility and scalability); describes the author’s web application – the FarmerProducts online store; identifies further ways to improve this web application.

Aspect-Oriented Modeling (AOM) has been the subject of intense research over the last decade and aims to provide numerous benefits to modeling, such as enhanced modularization, easier evolution, higher quality as well as reduced modeling effort. However, these benefits can only be obtained at the cost of learning and applying new modeling approaches. Studying their applicability is therefore important to assess whether they are worth using in practice. In this paper, we report a controlled experiment to assess the applicability of AOM, focusing on a recently published UML profile (AspectSM). This profile was originally designed to support model-based robustness testing in an industrial context but is applicable to the behavioral modeling of other crosscutting concerns. This experiment assesses the applicability of AspectSM from two aspects: the quality of derived state machines and the effort required to build them. With AspectSM, a crosscutting behavior is modeled using an "aspect state machine". The applicability of aspect state machines is evaluated by comparing them with standard UML state machines that directly model the entire system behavior, including crosscutting concerns. The quality of both aspect and standard UML state machines derived by subjects is measured by comparing them against predefined reference state machines. Results show that aspect state machines derived with AspectSM are significantly more complete and correct though AspectSM took significantly more time than the standard approach.

Kvik is an open-source system that we developed for explorative analysis of functional genomics data from large epidemiological studies. Creating such studies requires a significant amount of time and resources. It is therefore usual to reuse the data from one study for several research projects. Often each project requires implementing new analysis code, integration with specific knowledge bases, and specific visualizations. Existing data exploration tools do not provide all the required functionality for such multi-study data exploration. We have therefore developed the Kvik framework which makes it easy to implement specialized data exploration tools for specific projects. Applications in Kvik follow the three-tier architecture commonly used in web applications, with REST interfaces between the tiers. This makes it easy to adapt the applications to new statistical analyses, metadata, and visualizations. Kvik uses R to perform on-demand data analyses when researchers explore the data. In this note, we describe how we used Kvik to develop the Kvik Pathways application to explore gene expression data from healthy women with high and low plasma ratios of essential fatty acids using biological pathway visualizations. Researchers interact with Kvik Pathways through a web application that uses the JavaScript libraries Cytoscape.js and D3. We use Docker containers to make deployment of Kvik Pathways simple.

Complex event processing (CEP) and Reactive Languages (RLs) are examples of solutions for the so-called reactive applications. Such applications are designed to detect and react to changes or event occurrences as they happen in a timely fashion. Both CEP and RLs have been developed by different communities, yet some researchers agree that they share certain aspects and could perhaps be integrated. With that in mind, we developed a JavaScript library called CEP.js that leverages the well-known Reactive Extensions for JavaScript (RxJS) to offer not only general-purpose stream operations but also CEP ones. The fact of being a JavaScript library allows CEP.js to be used in Web applications and easily embedded into mobile applications. Therefore, it opens many possibilities for CEP in mobile client applications. It also raises the concern of energy efficiency since CEP applications commonly have to deal with a significant number of events, and its continuous operations on data flows may incur significant processing. Even though CEP.js has been designed after RxJS, it was conceived in a loosely coupled way that the underlying reactive library should be easily replaced if needed. In addition to presenting the CEP.js library, in this paper, we investigate if there is any significant change in performance by running an experiment where the replacement of the reactive library used in CEP.js is the main factor analyzed. The experiment was executed in different Android devices, focusing specifically on energy consumption, an essential non-functional requirement in the smartphone realm.

JavaScript libraries, such as JQuery, are widely used in web applications. In these libraries' event delegation models, a DOM element's event handler is usually bound to its parent nodes. This makes it difficult for developers to figure out the user-defined event handlers of a specified DOM element. In this paper, we propose an approach that identifies the user-defined event handlers of DOM elements in a web page. We dynamically collect the execution trace for each triggered event in a web page, and analyze how each function is used in the execution trace to discover the event handlers for each event. We evaluate our approach on seven real-world web applications. The result shows that our approach is effective, with an overall precision of 100% and recall of 99.8%.

The testing of Ajax (Asynchronous JavaScript and XML) web applications poses novel challenges for testers because Ajax constructs dynamic web applications by using Asynchronous communication and run time Document Object Model (DOM) manipulation. Ajax involves extreme dynamism, which induces novel kind of issues like state explosion, triggering state changes and unreachable states etc. that require more demanding web-testing methods. Model based testing is amongst the effective approaches to detect faults in web applications. However, the state model generated for an Ajax application can be enormous and may be hit by state explosion problem for large number of user action based changes and for immense dynamism. Recent research has not addressed this issue comprehensively because existing techniques either apply partial reduction or compromise the effectiveness of testing. This research uses soft computing based Fuzzy C Means (FCM) clustering algorithm to generate state machine model of an Ajax web application. The focus is on devising a framework to avoid the state explosion problem. The framework prioritizes the requirements and use cases based on requirements weightage, stakeholder weightage and user session based use case frequency. FCM uses this data to reduce the state space by identifying the most pivotal usage areas. The resultant DOM mutations for only these usage areas are considered to induce the finite state machine thus avoiding the state explosion. Experimental results show that the framework controls the size of generated state machine without compromising the effectiveness of testing.

Annotation: This research explores the application of information and communication technologies in education, specifically the use of JavaScript scripts on the Moodle platform for teaching discrete mathematics. Digital technologies enhance interactivity, adaptability, and automation in assessment. JavaScript enables the creation of web applications for visualizing mathematical concepts, automating assignment evaluation, and developing educational platforms. Special attention is given to the Ford-Fulkerson algorithm for finding the maximum flow in graphs and its practical implementation in modeling transport and communication networks. JavaScript libraries such as Vis.js and Chart.js effectively visualize graph structures and truth tables. Moodle allows for the integration of custom plugins for algorithmic computations, improving the quality of education. Implementing JavaScript in education not only saves time for instructors and students but also facilitates deeper comprehension of complex mathematical concepts and enhances students’ digital literacy. By leveraging JavaScript, students can interact with algorithms, analyze large sets of mathematical data, and receive instant feedback on their calculations, fostering a more engaging and efficient learning experience.

If-transpiler: Inlining of hybrid flow-sensitive security monitor for JavaScript

Dreamweaver CS4 is a massive step forward in terms of integration with the rest of the CS4 suite (Flash, Fireworks, Photoshop, etc.), and also includes a whole host of exciting new features of its own. The Essential Guide to Dreamweaver CS4 with CSS, Ajax, and PHP concentrates on getting the best out of Dreamweaver CS4, rather than going into every menu item and toolbar icon. The emphasis is on developing websites compliant with the latest web standards, using CSS, JavaScript libraries (with particular emphasis on Spry, Adobe's implementation of Ajax), and PHP. The book covers all aspects of the new user interface, including workspace layouts, iconic panels, the related documents feature, Live View, Code Navigator, and Live Code. It also shows how to use the improved CSS editing features, and JavaScript code introspection. There is also coverage of other new features, such as version control through Subversion integration, and the improved support for Photoshop integration through the use of Smart Objects. What you'll learn Streamline your workflow with the Related Files toolbar, Live view, and the Code Navigator Bring your pages alive with Ajax widgets from Spry, jQuery, and the Yahoo! User Interface Library Use server-side includes, templates, and Adobe's InContext Editing online service Create dynamic web applications using Dreamweaver's PHP server behaviors Build real world web site functions, such as form validation, random quote generator, search function, user management/login pages, dynamic Ajax gallery, and much more Consume RSS feeds and create Spry data sets How to publish your site after you've created it

The microprogrammed approach to implementing control state machines has been used widely since the early 1960s and has the advantages of structured programming and fixed timing characteristics. With microprogramming, state machine changes require only a change in memory contents, so the rate at which the controller can be clocked does not change no matter how significant the program change. This approach is in contrast to the standard state machine approach with state transitions described in a hardware description language like VHDL or Verilog, where design changes can dramatically impact the logic equations, amount of combinational logic, and clock frequency. This article introduces the microprogramming technique and presents a microprogrammed control unit that has been tailored to implementation in field programable gut arrays. The sequencer presented supports both nested subroutines and nested loops and can operate in both pipelined and non‐pipelined modes. Althouse not attractive for a small number of states, the microprogrammed approach has significant advantages for complex controllers with a large number of states.