Local Reasoning about Web Programs

Since 1990, the world wide web has evolved from a static collection of reference pages to a dynamic programming and application-hosting environment. At the core of this evolution is the programming language JavaScript and the XML update library "DOM". Every modern web browser contains a DOM implementation which allows JavaScript programs to read and alter the web page that the user is currently viewing. JavaScript and DOM are extremely successful, and this success may be in part due to their highly dynamic and tightly integrated nature. However, this very nature hinders formal program analysis and tool development. Even the implementation independent specification that defines DOM is largely written in the English language, and not using any formal system. While client-side web programming was once a simple discipline of form validation and interface trickery, it is fast becoming a far more serious business encompassing application development for the emerging ubiquitous "cloud". As this evolution gains pace there is an increasing demand for client-side tool support of the sort commonly enjoyed by "enterprise" programmers, working in more easily analysed languages such as Java. This thesis makes use of recent developments in program reasoning using context logic to provide the first formal, compositional specification for the Fundamental Interfaces of DOM Core Level 1. It presents both a big-step operational semantics for the necessary operations of the library and a context logic for reasoning about programs which use the library. Finally, it presents example programs that use the library and shows how context logic can be used to prove useful properties of those programs

Local reasoning about mashups

Web mashups are complex programs that dynamically compose XML data and JavaScript code from many sources. Whereas data is sometimes formally specified by XML schema, code never is. This makes it difficult to construct reliable software. Using local Hoare reasoning, introduced in separation logic to reason about e.g. C programs and extended in context logic to reason about e.g. the DOM library, we are able to reason about mashup programs, proving that they are fault-free and providing specifications for code that are analogous to XML schema for data

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

Systematic composition of distributed objects: Processes and sessions

We consider a system with the infrastructure for the creation and interconnection of large numbers of distributed persistent objects. This system is exemplified by the Internet: potentially, every appliance and document on the Internet has both persistent state and the ability to interact with large numbers of other appliances and documents on the Internet. This paper elucidates the characteristics of such a system, and proposes the compositional requirements of its corresponding infrastructure. We explore the problems of specifying, composing, reasoning about and implementing applications in such a system. A specific concern of our research is developing the infrastructure to support structuring distributed applications by using sequential, choice and parallel composition, in the anarchic environment where application compositions may be unforeseeable and interactions may be unknown prior to actually occurring. The structuring concepts discussed are relevant to a wide range of distributed applications; our implementation is illustrated with collaborative Java processes interacting over the Internet, but the methodology provided can be applied independent of specific platforms

The Meaning of Memory Safety

We give a rigorous characterization of what it means for a programming language to be memory safe, capturing the intuition that memory safety supports local reasoning about state. We formalize this principle in two ways. First, we show how a small memory-safe language validates a noninterference property: a program can neither affect nor be affected by unreachable parts of the state. Second, we extend separation logic, a proof system for heap-manipulating programs, with a memory-safe variant of its frame rule. The new rule is stronger because it applies even when parts of the program are buggy or malicious, but also weaker because it demands a stricter form of separation between parts of the program state. We also consider a number of pragmatically motivated variations on memory safety and the reasoning principles they support. As an application of our characterization, we evaluate the security of a previously proposed dynamic monitor for memory safety of heap-allocated data.Comment: POST'18 final versio

Promises and Challenges of Teaching Statistical Reasoning to Journalism Undergraduates: Twin Surveys of Department Heads, 1997 and 2008

This research is dedicated to the memory of Victor Cohn, former science reporter for the Washington Post and often considered the dean of science writers, who collaborated on the first wave of the survey. The 1997 survey was supported by a grant from the American Statistical Association and the 2008 survey by a grant from the Communication graduate program at Marquette University. Special thanks to research assistants Kathryn Zabriskie and Gongke Li for their valuable help in the survey. The analyses and conclusions are solely those of the authors