Scott Meyers

Difficulties in integrating multiview development systems

Drawbacks of current approaches to integrating multiple perspectives in a development environment are discussed. An integrated environment is defined as one in which a dynamic collection of tools can work together on a single system so that changes made to the system by one tool can be seen by other tools, and integration criteria are set forth. Five representative approaches to systems integration-shared file systems, selective broadcasting, simple databases, view-oriented databases, and canonical representation-are examined, and their relative strengths and weaknesses are summarized. None of the integration mechanisms is shown to be uniformly superior to the others. The issue of environment evolution and its effect on integration is addressed.<<ETX>>

Using GELO to visualize software systems

GELO is a package that supports the interactive graphical display of software systems. Its features include built-in panning and zooming, abstraction of objects too small to see, pick correlation, windowing, and scroll bars. GELO creates a hierarchy of graphical objects that correspond to the components of the structure being displayed. Five flavors of graphical objects are supported, including those for simple structures, tiled layouts, and graph-based layouts. This framework is powerful enough to handle a wide variety of graphical visualizations, and it is general enough that new object flavors can be smoothly integrated in the future. GELO is easy to learn and to use, and is presently employed in two software development environments. Among its current applications are a variety of visual languages, an interactive display of call graphs, an interactive display of data structures, and a graphical representation of module dependencies.

Support for maintaining object-oriented programs

The authors explain how inheritance and dynamic binding make object-oriented programs difficult to maintain, and give a concrete example of the problems that arise. They show that the difficulty lies in the fact that conventional tools are poorly suited for work with object-oriented languages, and argue that semantics-based tools are essential for effective maintenance of object-oriented programs. The authors describe a system developed for working with C++ programs. This system comprises a relational database system for information about programs, and an interactive database interface integrated with a text editor. They describe the system architecture, detail the database relations, provide informal evidence on the systems effectiveness, and compare it to other research with similar goals.<<ETX>>

Facilitating software maintenance by automated detection of constraint violations

CCEL, a language that allows programmers to formally express constraints on their software systems and to automatically detect violations of these constraints, is introduced. The power, flexibility, and overall utility of CCEL are demonstrated by examples showing how it can express real constraints from real software developers for real systems.<<ETX>>

Representing programs in multiparadigm software development environments

A canonical program representation, semantic program graphs (SPGs), is described, and it is shown how SPGs can act as the foundation for multiparadigm software development environments. Using SPGs as the basis for program representation allows developers to see different views of programs that correspond to different ways of thinking about them, and it allows editors to be created so that the underlying program can be edited using any of the paradigms. As the sole program representation, SPGs also facilitate communication between paradigms: changes made in one view can be immediately reflected in all other views.<<ETX>>