Pieter W. M. Koopman

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Software testing is a labor-intensive and hence expensive, yet heavily used technique to control quality. In this paper we introduce Gast, a fully automatic test-tool. Properties from first order logic can be expressed in the system, Gast automatically generates appropriate test-data, evaluates the property for these values, and analyzes the test-results.(More)
In this paper we introduce the iTask system: a set of combinators to specify <i>work flows</i> in a pure functional language at a very high level of abstraction. Work flow systems are automated systems in which <i>tasks</i> are coordinated that have to be executed by humans and computers. The combinators that we propose support work flow patterns commonly(More)
This paper describes an efficient interpreter for lazy functional languages like Haskell and Clean. The interpreter is based on the elimination of algebraic data types and pattern-based function definitions by mapping them to functions using a new efficient variant of the Church encoding. The transformation is simple and yields concise code. We illustrate(More)
G∀ST is a fully automatic test system. Given a logical property, stated as a function, it is able to generate appropriate test values, to execute tests with these values, and to evaluate the results of these tests. Many reactive systems, like automata and protocols, however, are specified by a model rather than in logic. There exist tools that are able to(More)
Workflow management systems (WFMS) are software systems that coordinate the tasks human workers and computers have to perform to achieve a certain goal based on a given workflow description. Due to changing circumstances, it happens often that some tasks in a running workflow need to be performed differently than originally planned and specified. Most(More)
<i>Task-Oriented Programming</i> (TOP) is a novel programming paradigm for the construction of distributed systems where users work together on the internet. When multiple users collaborate, they need to interact with each other frequently. TOP supports the definition of tasks that react to the progress made by others. With TOP, complex multi-user(More)
In this paper we present a novel automated, on-line, model-based testing system for on-the-fly testing of thin-client web applications. Web applications are specified by means of Extended State Machines. To handle dynamic web applications, arbitrarily large and complex state input and output types, and the transport of information from the web-page to the(More)
More and more software systems use a browser as the universal graphical user interface. As a consequence these applications inherit browser navigation as part of their interface. Typical browser actions are the use of the back-and forward-button and the cloning of windows. Browser navigation is difficult to deal with because it has effects that are noticed(More)
Although computer systems penetrate all facets of society, the software running those systems may contain many errors. Producing high quality software appears to be difficult and very expensive. Even determining the quality of software is not easy. Testing is by far the most used way to estimate the quality of software. Testing itself is not easy and time(More)