Program Transformations in Magnolia

We explore program transformations in the context of the Magnolia programming language. We discuss research and implementations of transformation techniques, scenarios to put them to use in Magnolia, interfacing with transformations, and potential workflows and tooling that this approach to programming enables.Vi utforsker program transformasjoner med tanke på programmeringsspråket Magnolia. Vi diskuterer forsking og implementasjoner av transformasjonsteknikker, sammenhenger der vi kan bruke dei i Magnolia, grensesnitt til transformasjoner, og potensielle arbeidsflyt og verktøy som denne tilnærmingen til programmering kan tillate og fremme.Masteroppgåve i informatikkINF39

Conference on the Programming Environment for Development of Numerical Software

Systematic approaches to numerical software development and testing are presented

Knowledge restructing and the development of expertise in computer programming

This thesis reports a number of empirical studies exploring the development of expertise in computer programming. Experiments 1 and 2 are concerned with the way in which the possession of design experience can influence the perception and use of cues to various program structures. Experiment 3 examines how violations to standard conventions for constructing programs can affect the comprehension of expert, intermediate and novice subjects. Experiment 4 looks at the differences in strategy that are exhibited by subjects of varying skill level when constructing programs in different languages. Experiment 5 takes these ideas further to examine the temporal distribution of different forms of strategy during a program generation task. Experiment 6 provides evidence for salient cognitive structures derived from reaction time and error data in the context of a recognition task. Experiments 7 and 8 are concerned with the role of working memory in program generation and suggest that one aspect of expertise in the programming domain involves the acquisition of strategies for utilising display-based information. The final chapter attempts to bring these experimental findings together in terms of a model of knowledge organisation that stresses the importance of knowledge restructuring processes in the development of expertise. This is contrasted with existing models which have tended to place emphasis upon schemata acquisition and generalisation as the fundamental modes of learning associated with skill development. The work reported here suggests that a fine-grained restructuring of individual schemata takes places during the later stages of skill development. It is argued that those mechanisms currently thought to be associated with the development of expertise may not fully account for the strategic changes and the types of error typically found in the transition between novice, intermediate and expert problem solvers. This work has a number of implications for existing theories of skill acquisition. In particular, it questions the ability of such theories to account for subtle changes in the various manifestations of skilled performance that are associated with increasing expertise. Secondly, the work reported in this thesis attempts to show how specific forms of training might give rise to the knowledge restructuring process that is proposed. Finally, the thesis stresses the important role of display-based problem solving in complex tasks such as programming and highlights the role of programming language notation as a mediating factor in the development and acquisition of problem solving strategies

Ahead-of-Time Algebraic Compilation for Safety-Critical Java

In recent years Java has been increasingly considered as a language for safety-critical embedded systems. However, some features of Java are unsuitable for such systems. This has resulted in the creation of Safety-Critical Java (SCJ), which facilitates the development of certifiable real-time and embedded Java programs. SCJ uses different scheduling and memory management models to standard Java, so it requires a specialised virtual machine (SCJVM). A common approach is to compile Java bytecode program to a native language, usually C, ahead-of-time for greater performance on low-resource embedded systems. Given the safety-critical nature of the applications, it must be ensured that the virtual machine is correct. However, so far, formal verification has not been applied to any SCJVM. This thesis contributes to the formal verification of SCJVMs that utilise ahead-of-time compilation by presenting a verification of compilation from Java bytecode to C. The approach we adopt is an adaptation of the algebraic approach developed by Sampaio and Hoare. We start with a formal specification of an SCJVM executing the bytecodes of a program, and transform it, through the application of proven compilation rules, to a representation of the target C code. Thus, our contributions are a formal specification of an SCJVM, a set of compilation rules with proofs, and a strategy for applying those compilation rules. Our compilation strategy can be used as the basis for an implementation of an ahead-of-time compiling SCJVM, or verification of an existing implementation. Additionally, our formal model of an SCJVM may be used as a specification for creating an interpreting SCJVM. To ensure the applicability of our results, we base our work on icecap, the only currently available SCJVM that is open source and up-to-date with the SCJ standard