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In this paper we report on an attempt to classify student problems and mistakes, and measuring the frequency of particular problems in a firstsemester programming course. We also propose a scheme for annotating student hand-ins which may be useful both in grading and in future research. acceptedVersion

A concept (or signature) describes the interface of a set of abstract types by listing the operations that should be supported for those types. When implementing a generic operation, such as sorting, we may then specify requirements such as “elements must be comparable” by requiring that the element type models the Comparable concept. We may also use axioms to describe behaviour that should be common to all models of a concept. However, the operations specified by the concept are not always the ones that are best suited for the implementation. For example, numbers and matrices may both be addable, but adding two numbers is conveniently done by using a return value, whereas adding a sparse and a dense matrix is probably best achieved by modifying the dense matrix. In both cases, though, we may want to pretend we're using a simple function with a return value, as this most closely matches the notation we know from mathematics. This paper presents two simple concepts to break the notational tie between implementation and use of an operation: functionalisation, which derives a set of canonical pure functions from a procedure; and mutification, which translates calls using the functionalised declarations into calls to the implemented procedure. publishedVersion

Parsing is the process of analysing an input string in order to extract a structured representation of its content (a syntax tree) with respect to a specific language. In the thesis, we focus on parsing formal languages, such as programming or markup languages — as opposed to natural spoken languages. Unlike natural languages, formal languages are never ambiguous: there is only a single correct interpretation of the input. Parsing is a pervasive activity: every time a source file must be turned into executable code, a parser is required. Similarly, parsers are used to convert input files into relevant data structures. It is fair to say that most programs include a parser — sometimes many. As such, making parsers easier to write, use, and modify is a broadly beneficial endeavour. This thesis is concerned with the limitations of currently available parsing systems, and how to overcome them. In particular, we show how to develop a simple yet expressive notation that can be easily extended, and build upon this basis to add context-sensitive parsing to the parsing system, robust support for infix expression (avoiding expressiveness and performance issues relating to associativity selection) as well as many more expressiveness and usability features — such as permissive parsing and debugging tools. (FSA - Sciences de l'ingénieur) -- UCL, 2019

Integrating ecosystem data into developer tools can be very beneficial but is usually complicated. By automating the routine parts of this task we can reduce the amount of work needed to develop these tools. We have developed a framework that allows developers to quickly develop new tools that use ecosystem data. This framework automates the execution of user-defined analyses on ecosystem projects, allowing the developer to focus only on what ecosystem data is needed for her tool and how to present it.