Most graphical user interface (GUI) libraries forbid accessing UI elements from threads other than the UI event loop thread. Violating this requirement leads to a program crash or an inconsistent UI. Unfortunately, such errors are all too common in GUI programs. We present a polymorphic type and effect system that prevents non-UI threads from accessing UI objects or invoking UI-thread-only meth...

With the recent success of refactoring, UML tool vendors seek ways to support programmers in applying a (sequence of) refactoring(s). The problem with such tools is that the UML metamodel – on which their repository is based – is inadequate to maintain the consistency between the model and the code while one of them gets refactored. Therefore, we propose a set of minimal extensions to the UML m...

With the increased interest in refactoring, UML tool vendors seek ways to support software developers in applying a (sequence of) refactoring(s). The problem with such tools is that the UML metamodel – on which their repository is based – is inadequate to maintain the consistency between the model and the code while one of them gets refactored. Therefore, we propose a set of minimal extensions ...

Recently, code clone has been regarded as one of factors that make software maintenance more difficult. A code clone is a code fragment in a source code that is identical or similar to another. For example, if we modify a code fragment which has code clones, it is necessary to consider whether we have to modify each of its code clones. It is generally said that code clone is one of bad-smells t...

-Object oriented software systems are subject to frequent modifications either during development (iterative, agile software development) or software evolution. For such systems which have large number of classes, detection of design defects is a complex task. Bad smells are used to identify design defects in object oriented software design. Identification of bad smells allows us to apply appro...

Design defects, antipatterns, code smells are software defects at the architectural level that must be detected and corrected to improve software quality. Automatic detection and correction of these software architectural defects, which suffer of a lack of tools, are important to ease the maintenance of objectoriented architectures and thus to reduce the cost of maintenance. A clear understandi...

In this showpiece, we demonstrate the functionality of Quality Hound — an online program analysis tool that takes as input a Scratch project and presents to the user a visual representation of the detected quality problems. Made accessible via a browser-based user interface, Quality Hound is instantaneously accessible to any Scratch user all over the world. The design of Quality Hound is inform...